Federal Registers - Table of Contents Federal Registers - Table of Contents
• Publication Date: 02/14/2007
• Publication Type: Final Rules
• Fed Register #: 72:7135-7221
• Standard Number: 1910
• Title: Electrical Standard; Final Rule

[Federal Register: February 14, 2007 (Volume 72, Number 30)]
[Rules and Regulations]               
[Page 7135-7221]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr14fe07-14]                         

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Part II

Department of Labor

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Occupational Safety and Health Administration

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29 CFR Part 1910

Electrical Standard; Final Rule

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DEPARTMENT OF LABOR

Occupational Safety and Health Administration

29 CFR Part 1910

[Docket No. S-108C]
RIN 1218-AB95
 
Electrical Standard

AGENCY: Occupational Safety and Health Administration, Labor.

ACTION: Final rule.

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SUMMARY: The Occupational Safety and Health Administration (OSHA) is 
revising the general industry electrical installation standard found in 
Subpart S of 29 CFR Part 1910. The Agency has determined that 
electrical hazards in the workplace pose a significant risk of injury 
or death to employees, and that the requirements in the revised 
standard, which draw heavily from the 2000 edition of the National Fire 
Protection Association's (NFPA) Electrical Safety Requirements for 
Employee Workplaces (NFPA 70E), and the 2002 edition of the National 
Electrical Code (NEC), are reasonably necessary to provide protection 
from these hazards. This final rule focuses on safety in the design and 
installation of electric equipment in the workplace. This revision will 
provide the first update of the installation requirements in the 
general industry electrical installation standard since 1981.
    OSHA is also replacing the reference to the 1971 NEC in the 
mandatory appendix to the general industry powered platform standard 
found in Subpart F of 29 CFR Part 1910 with a reference to OSHA's 
electrical installation standard.

DATES: This final rule becomes effective on August 13, 2007.

ADDRESSES: In accordance with 28 U.S.C. 2112(a), the Agency designates 
the Associate Solicitor of Labor for Occupational Safety and Health, 
Office of the Solicitor of Labor, Room S4004, U.S. Department of Labor, 
200 Constitution Avenue, NW., Washington, DC 20210, to receive 
petitions for review of the final rule.

FOR FURTHER INFORMATION CONTACT: For general information and press 
inquiries, contact Mr. Kevin Ropp, Director, Office of Communications, 
Room N-3647, OSHA, U.S. Department of Labor, 200 Constitution Avenue, 
NW., Washington, DC 20210; telephone (202) 693-1999. For technical 
inquiries, contact Mr. David Wallis, Directorate of Standards and 
Guidance, Room N-3609, OSHA, U.S. Department of Labor, 200 Constitution 
Avenue, NW., Washington, DC 20210; telephone (202) 693-2222.
    For additional copies of this Federal Register notice, contact 
OSHA, Office of Publications, Room N-3101, U.S. Department of Labor, 
200 Constitution Avenue, NW., Washington, DC 20210; telephone (202) 
693-1888. Electronic copies of this Federal Register notice, as well as 
news releases and other relevant documents, are available at OSHA's Web 
page on the Internet at http://www.osha.gov.


SUPPLEMENTARY INFORMATION:

I. Introduction

    This final rule revises OSHA's existing standard for electrical 
installations, which is contained in Sec. Sec.  1910.302 through 
1910.308 of Subpart S, with relevant definitions in Sec.  1910.399. It 
applies, as the existing standard does, to employers in general 
industry and in shipyard employment, longshoring, and marine terminals.
    OSHA undertook the project to revise Subpart S for two major 
reasons. First, the Agency wanted the standard to reflect the most 
current practice and technology in the industry. The existing standard 
is based on a national consensus standard, the 1979 edition of Part I 
of NFPA 70E, entitled Standard for Electrical Safety Requirements for 
Employee Workplaces. That consensus standard has been updated several 
times since OSHA last revised its electrical installation requirements 
in 1981. The final rule being published today is based on Part I of the 
2000 edition of NFPA 70E. Second, in implementing this rule, OSHA is 
responding to requests from stakeholders that the Agency revise Subpart 
S so that it reflects the most recent editions of NFPA 70E and the 
NEC.\1\ These stakeholders argued that interested members of the public 
have had substantial input into the content of NFPA 70E and that 
industry is complying with that consensus standard in its present form. 
The revised standard will be more flexible and efficient for 
stakeholders, including small businesses, while improving safety for 
employees.
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    \1\ See, for example, letters from: Judith Gorman, Managing 
Director of the Institute of Electrical and Electronic Engineers; 
George D. Miller, President and Chief Executive Officer of the 
National Fire Protection Association; Frank K. Kitzantides, Vice 
President of Engineering at the National Electrical Manufacturers 
Association; and Kari P. Barrett, Director of Regulatory and 
Technical Affairs, Plant Operations, at the American Chemistry 
Council (Exhibit 2-62, 2-63, 2-64, 2-65).
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    OSHA's existing electrical standard in Sec. Sec.  1910.302 through 
1910.308 is based on the 1979 edition of NFPA 70E, which is a national 
consensus standard developed by a cross section of industry, labor, and 
other allied interests. Consensus standards like the NEC and NFPA 70E 
provide nationally recognized safe electrical installation 
requirements. Additionally, the consensus process used in developing 
the 2000 edition of NFPA 70E, Part 1 of which is based on the NEC, 
ensures that requirements contained in that standard are current and at 
the forefront of electrical safety technology. Because the primary 
objective of this revision of Subpart S is to update the standard to 
recognize, and in some cases require, the more current electrical 
safety technology, OSHA believes that the more recent editions of NFPA 
70E should be the foundation of the final standard.\2\ Lastly, the 
Agency has determined that electrical hazards in general industry 
workplaces pose a significant risk and that the final standard will 
substantially reduce that risk.
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    \2\ A newer edition of NFPA 70E was published shortly after OSHA 
issued the proposed rule. Whether the final rule should be based on 
this edition, NFPA 70E-2004, is one of the issues raised by comments 
on the proposal. See the discussion of this issue in section V, 
Summary and Explanation of the Final Standard.
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    The remainder of the preamble discusses the background of the final 
rule, the history of the standard, and the legal authority for the 
standard; provides a summary and explanation of the final standard; 
includes the final economic and regulatory flexibility analysis and the 
information collections associated with the rule; and covers other 
miscellaneous topics. The outline of the preamble is as follows:

I. Introduction
II. Background
III. History of the Standard
IV. Legal Authority
V. Summary and Explanation of the Final Standard
VI. Final Economic and Regulatory Screening Analysis
VII. State Plan Standards
VIII. Environmental Impact Analysis
IX. Unfunded Mandates
X. Federalism
XI. OMB Review under the Paperwork Reduction Act of 1995
XII. Effective Date and Date of Application

II. Background

A. Hazards Associated With Electricity

    Electricity is widely recognized as a serious workplace hazard, 
exposing employees to electric shock, burns, fires, and explosions. 
According to the Bureau of Labor Statistics, 289 employees were killed 
by contact with electric current in 2002 (Ex. 2-8). Other employees 
have been killed or injured in fires and explosions caused by electricity.
    It is well known that the human body will conduct electricity. If 
direct body contact is made with an electrically energized part while a 
similar contact is made simultaneously with another conductive surface 
that is maintained at a different electrical potential, a current will 
flow, entering the body at one contact point, traversing the body, and 
then exiting at the other contact point, usually the ground. Each year 
many employees suffer pain, injuries, and death from such electric 
shocks.
    Current through the body, even at levels as low as 3 milliamperes, 
can also cause injuries of an indirect or secondary nature in which 
involuntary muscular reaction from the electric shock can cause 
bruises, bone fractures and even death resulting from collisions or 
falls.
    Burns suffered in electrical accidents can be very serious. These 
burns may be of three basic types: electrical burns, arc burns, and 
thermal contact burns. Electrical burns are the result of the electric 
current flowing in the tissues, and may be either skin deep or may 
affect deeper layers (such as muscles and bones) or both. Tissue damage 
is caused by the heat generated from the current flow; if the energy 
delivered by the electric shock is high, the body cannot dissipate the 
heat, and the tissue is burned. Typically, such electrical burns are 
slow to heal. Arc burns are the result of high temperatures produced by 
electric arcs or by explosions close to the body. Finally, thermal 
contact burns are those normally experienced from the skin contacting 
hot surfaces of overheated electric conductors, conduits, or other 
energized equipment. In some circumstances, all three types of burns 
may be produced simultaneously.
    If the current involved is great enough, electric arcs can start a 
fire. Fires can also be created by overheating equipment or by 
conductors carrying too much current. Extremely high-energy arcs can 
damage equipment, causing fragmented metal to fly in all directions. In 
atmospheres that contain explosive gases or vapors or combustible 
dusts, even low-energy arcs can cause violent explosions.

B. Nature of Electrical Accidents

    Electrical accidents, when initially studied, often appear to be 
caused by circumstances that are varied and peculiar to the particular 
incidents involved. However, further consideration usually reveals the 
underlying cause to be a combination of three possible factors: work 
involving unsafe equipment and installations; workplaces made unsafe by 
the environment; and unsafe work performance (unsafe acts). The first 
two factors are sometimes considered together and simply referred to as 
unsafe conditions. Thus, electrical accidents can be generally 
considered as being caused by unsafe conditions, unsafe acts, or, in 
what is usually the case, combinations of the two. It should also be 
noted that inadequate maintenance can cause equipment or installations 
that were originally considered safe to deteriorate, resulting in an 
unsafe condition.
    Some unsafe electric equipment and installations can be identified, 
for example, by the presence of faulty insulation, improper grounding, 
loose connections, defective parts, ground faults in equipment, 
unguarded live parts, and underrated equipment. The environment can 
also be a contributory factor to electrical accidents in a number of 
ways. Environments containing flammable vapors, liquids, or gases; 
areas containing corrosive atmospheres; and wet and damp locations are 
some unsafe environments affecting electrical safety. Finally, unsafe 
acts include the failure to deenergize electric equipment when it is 
being repaired or inspected or the use of tools or equipment too close 
to energized parts.

C. Protective Measures

    There are various ways of protecting employees from the hazards of 
electric shock, including insulation and guarding of live parts. 
Insulation provides a barrier to the flow of current. To be effective, 
the insulation must be appropriate for the voltage, and the insulating 
material must be undamaged, clean, and dry. Guarding prevents the 
employee from coming too close to energized parts. It can be in the 
form of a physical barricade, or it can be provided by installing the 
live parts out of employees' reach. (This technique is known as 
"guarding by location.")
    Grounding is another method of protecting employees from electric 
shock; however, it is normally a secondary protective measure. To keep 
guards or enclosures at a common potential with earth, they are 
connected, by means of a grounding conductor, to ground. In addition, 
grounding provides a path of low impedance and of ample capacity back 
to the source to pass enough current to activate the overcurrent 
devices in the circuit. If a live part accidentally contacts a grounded 
enclosure, current flow is directed back to earth, and the circuit 
protective devices (for example, fuses and circuit breakers) can 
interrupt the circuit.
    If it draws too much current, electric equipment can overheat, 
which can result in fires. Overheating can also lead to electric shock 
hazards if the insulation protecting a conductor melts. Protecting 
electric equipment from overcurrent helps prevent this from happening.
    Designing and installing equipment to protect against dangerous 
arcing and overheating is also important in preventing unsafe 
conditions that can lead to fires, high energy electric arcs, and 
explosions. Employers and employees cannot usually detect improperly 
designed or rated equipment. Thus, OSHA relies on third-party testing 
and certification of electric equipment to ensure proper electrical 
design. This helps ensure, for example, that equipment will not 
overheat during normal operation and that equipment designed for use in 
a hazardous location will not cause a fire or explosion. It also helps 
ensure that equipment is appropriately rated and marked, allowing 
employees designing electrical installations and installing electric 
equipment to select equipment and size conductors in accordance with 
those ratings.\3\ Many of the requirements in OSHA's electrical 
standards in turn depend on accurate ratings on equipment.
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    \3\ Electric equipment is typically rated for use with certain 
voltages and current. For example, an electric hair dryer might be 
rated at 125 volts, 1875 watts. The voltage rating indicates the 
maximum voltage for which the equipment is rated. The wattage rating 
indicates how much power the equipment will draw when connected to a 
circuit at the maximum voltage. The current drawn by the equipment 
is the wattage rating divided by the voltage rating. Thus, the 
circuit voltage (120 volts, nominal) is less than the maximum rated 
voltage of the hair dryer (125 volts), and the circuit is rated for 
the current the equipment will draw (1875 watts/125 volts = 15 
amperes). Thus, the hair dryer would be suitable for use on a 120-
volt circuit capable of safely carrying 15 amperes.
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    These protective measures help ensure the safe installation of 
electric equipment and are prescribed by the requirements presently 
contained in 29 CFR Part 1910, Subpart S. Addressing common unsafe 
conditions, these rules cover such safety considerations as guarding 
and insulation of live parts, grounding of equipment enclosures, and 
protection of circuits from overcurrent. This rulemaking updates those 
requirements to make them consistent with the latest editions of NFPA 
70E. This revision will better protect employees by recognizing the 
latest techniques in electrical safety and by requiring installations 
to incorporate those techniques whenever necessary.

D. Significant Risk and Reduction in Risk

    As stated earlier, electricity has long been recognized as a 
serious workplace hazard exposing employees to dangers such as electric 
shock, electrocution, fires, and explosions. The 100-year-long history 
of the National Electrical Code, originally formulated and periodically 
updated by industry consensus, attests to this fact. The NEC has 
represented the continuing efforts of experts in electrical safety to 
address these hazards and provide standards for limiting exposure in 
all electrical installations, including workplaces. OSHA has determined 
that electrical hazards in the workplace pose a significant risk of 
injury or death to employees and that this final rule, which draws 
heavily on the experience of the NEC, will substantially reduce this 
risk.
    According to the U.S. Bureau of Labor Statistics, between 1992 and 
2002, an average of 295 employees died per year from contact with 
electric current, and between 1992 and 2001 an average of 4,309 
employees lost time away from work because of electrical injuries.\4\ 
Overall, there has been a downward trend in injuries and illnesses, but 
the percentage has varied from year to year. From 1992 to 2001, the 
number of injuries involving days away from work decreased by 29 
percent. From 1992 to 2002, the number of deaths decreased by 9 
percent. This downward trend is due, in major part, to 30 years of 
highly protective OSHA regulation in the area of electrical 
installation, based on the NEC and NFPA 70E standards. The final 
standard carries forward most of the existing requirements for 
electrical installations, with the new and revised requirements 
intended as fine tuning, introducing new technology along with other 
improvements in safety. By complying with the final standard, employers 
will prevent unsafe electrical conditions from occurring.
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    \4\ The Survey of Occupational Injuries and Illnesses and the 
Census of Fatal Occupational Injuries, http://www.bls.gov/iif/home.htm#tables.

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    While the number of deaths and injuries associated with electrical 
hazards has declined, contact with electric current still poses a 
significant risk to employees in the workplace, as evidenced by the 
numbers of deaths and serious injuries still occurring due to contact 
with electric current. This final rule will help further reduce the 
number of deaths and injuries associated with electrical hazards by 
providing additional requirements for installation safety and by 
recognizing alternative means of compliance.

III. History of the Standard

    On February 16, 1972, OSHA incorporated the 1971 edition of the 
National Fire Protection Association's (NFPA) National Electrical Code 
(NEC), NFPA 70-1971, by reference as its electrical standard for 
general industry (37 FR 3431). The Agency followed the procedures 
outlined in Section 6(a) of the Occupational Safety and Health Act of 
1970 (OSH Act; 29 U.S.C. 655), which directed the Secretary to adopt 
existing national consensus standards as OSHA standards within 2 years 
of the effective date of the OSH Act. In incorporating the 1971 NEC by 
reference, OSHA made the entire 1971 NEC applicable to all covered 
electrical installations made after March 15, 1972. For covered 
installations made before that date, OSHA listed about 16 provisions 
from the 1971 NEC that applied. No other provisions of the 1971 NEC 
applied to these older installations. Thus, older installations were 
"grandfathered" so that they did not need to meet most of the 
requirements in the consensus standard.
    On January 16, 1981, OSHA revised its electrical installation 
standard for general industry (46 FR 4034). This revision replaced the 
incorporation by reference of the 1971 NEC with relevant requirements 
from Part I of the 1979 edition of NFPA 70E. The revision simplified 
and clarified the electrical standard and updated its provisions to 
match the 1978 NEC (the latest edition available at the time). The 
standard was written to reduce the need for frequent revision and to 
avoid technological obsolescence. These goals were achieved--NFPA 70E 
had only minor changes over its initial 15 years of existence. The 
first substantial changes were introduced in the 1995 edition of NFPA 
70E.
    The 2000 edition of NFPA 70E contains a number of significant 
revisions, including a new, alternative method for classifying and 
installing equipment in Class I hazardous locations (see preamble 
Section I. N. Zone Classification, below). NFPA has recommended that 
OSHA revise its general industry electrical standards to reflect the 
latest edition of NFPA 70E, arguing that such a revision would provide 
a needed update to the OSHA standards and would better protect 
employees. This final rule responds to NFPA's recommendations with 
regard to installation safety. It also reflects the Agency's commitment 
to update its electrical standards, keep them consistent with NFPA 
standards, and ensure that they appropriately protect employees. The 
Agency intends to extend this commitment by using NFPA 70E as a basis 
for future revisions to its electrical safety-related work practice 
requirements and new requirements for electrical maintenance and 
special equipment.
    The proposed rule was published in the Federal Register on April 5, 
2004. The public had a 60-day comment period that ended on June 4, 
2004. OSHA received 38 comments on the proposed revision of OSHA's 
electrical installation standard for general industry. The Agency 
received one hearing request on the proposal, which was subsequently 
withdrawn.
    The comments addressed specific provisions in the proposal and 
raised several issues, including: (1) Whether OSHA should use the 
latest edition of NFPA 70E or the NEC to revise Subpart S; (2) whether 
OSHA should update the corresponding construction standard at the same 
time; (3) whether OSHA should address work practices and other revised 
provisions of NFPA 70E; and (4) what the effective date of the standard 
should be. (See section V, "Summary and Explanation of the Final 
Standard," later in the preamble, for a discussion of the comments.)

IV. Legal Authority

    The purpose of the OSH Act, 29 U.S.C. 651 et seq., is "to assure 
so far as possible every working man and woman in the Nation safe and 
healthful working conditions and to preserve our human resources." 29 
U.S.C. 651(b). To achieve this goal, Congress authorized the Secretary 
of Labor to promulgate and enforce occupational safety and health 
standards. 29 U.S.C. 655(b) & 658.
    A safety or health standard "requires conditions, or the adoption 
or use of one or more practices, means, methods, operations, or 
processes, reasonably necessary or appropriate to provide safe or 
healthful employment and places of employment." 29 U.S.C. 652(8). A 
standard is reasonably necessary or appropriate within the meaning of 
Section 652(8) if:
     A significant risk of material harm exists in the 
workplace and the proposed standard would substantially reduce or 
eliminate that workplace risk;
     It is technologically and economically feasible;
     It employs the most cost effective protective measures;
     It is consistent with prior Agency action or supported by 
a reasoned justification for departing from prior Agency action;
     It is supported by substantial evidence; and
     In the event the standard is preceded by a consensus 
standard, it is better able to effectuate the purposes of the OSH Act 
than the standard it supersedes.
    International Union, UAW v. OSHA (LOTO II), 37 F.3d 665, 668 (D.C. 
Cir. 1994).
    OSHA has generally considered an excess risk of 1 death per 1000 
employees over a 45-year working lifetime as clearly representing a 
significant risk (see Industrial Union Dept. v. American Petroleum 
Institute (Benzene), 448 U.S. 607, 655 (1980); International Union v. 
Pendergrass (Formaldehyde), 878 F.2d 389, 392-93 (D.C. Cir. 1989); 
Building and Construction Trades Dept., AFL-CIO v. Brock (Asbestos), 
838 F.2d 1258, 1264-65 (D.C. Cir. 1988)).
    A standard is considered technologically feasible if the protective 
measures it requires already exist, can be brought into existence with 
available technology, or can be created with technology that can 
reasonably be expected to be developed (see American Iron and Steel 
Institute v. OSHA (Lead II), 939 F.2d 975, 980 (D.C. Cir. 1991)). A 
standard is economically feasible when industry can absorb or pass on 
the costs of compliance without threatening the industry's long-term 
profitability or competitive structure (see American Textile Mfrs. 
Institute v. OSHA (Cotton Dust), 452 U.S. 490, 530 n. 55 (1981); Lead 
II, 939 F.2d at 980). A standard is cost effective if the protective 
measures it requires are the least costly of the available alternatives 
that achieve the same level of protection (see LOTO II, 37 F.3d at 
668).
    All OSHA standards must be highly protective (LOTO II, 37 F.3d at 
669) and, where practical, "expressed in terms of objective criteria 
and of the performance desired." 29 U.S.C. 655(b)(5). Finally, the OSH 
Act requires that when promulgating a rule that differs substantially 
from a national consensus standard, OSHA must explain why the 
promulgated rule is a better method for effectuating the purpose of the 
OSH Act. 29 U.S.C. 655(b)(8). As discussed earlier, OSHA is using NFPA 
70E as the basis for its final rule, with some modifications as 
necessary, as explained in detail in the next section of the preamble.

V. Summary and Explanation of the Final Standard

    This section discusses the important elements of the final 
standard, explains the purpose of the individual requirements, and 
explains any differences between the final standard and the existing 
standard. This section also discusses and resolves issues raised during 
the comment period, significant comments received as part of the 
rulemaking record, and any substantive changes that were made from the 
language of the proposed rule. References in parentheses are to 
exhibits in the rulemaking record. Except as noted, OSHA is carrying 
forward the language from the proposal into the final rule without 
substantive differences.

A. Issues

    1. Comments supporting the revision of Subpart S. The vast majority 
of the comments supported OSHA's efforts to update the general industry 
electrical standards (Exs. 3-3, 3-4, 3-6, 3-7, 3-8, 3-9, 4-10, 4-24). 
For example, the National Petrochemical & Refiners Association 
expressed support for updating Subpart S so that it is consistent with 
the current editions of the NFPA 70E and the NEC, because, they stated, 
its members place a high priority on safety and understand the 
necessity for electrical installation standards (Ex. 3-4). The American 
Society of Safety Engineers (ASSE) also supported the proposal, 
stating: "It is appropriate to move forward with this revision, given 
the seriousness of electrical hazards and the fact that nearly 300 
workers are killed each year from contact with electrical current or as 
the result of injuries caused by fires and explosions related to 
electrical accidents [Ex. 3-5]."
    The National Institute for Occupational Safety and Health (NIOSH) 
and the North Carolina Department of Labor also supported OSHA's 
proposed revision (Exs. 3-9, 5-2). NIOSH stated: "The proposed revised 
standard will provide workers in general industry and maritime 
employment with improved protection against injuries and death from 
electrical hazards [Ex. 3-9]." The North Carolina Department of Labor 
expressed a similar view, stating: "The revisions proposed to the 
existing standard should provide a greater measure of protection to 
employees working on and around electrical equipment and installations 
[Ex. 5-2]."
    OSHA appreciates the support of these commenters. The Agency 
believes that the final standard will better protect employees than the 
existing standard. The record overwhelmingly supports this view.
    2. OSHA should use the latest version of NFPA 70E or the NEC. OSHA 
received several comments recommending that the standard be based on 
the latest version of NFPA 70E or the NEC (Exs. 3-8, 4-3, 4-6, 4-8, 4-
11). Some of the commenters argued that, by using the 2000 edition of 
the NFPA 70E rather than the more recent 2004 edition, OSHA was not 
reflecting the most current practices and technology. For example, 
David Soffrin of the American Petroleum Institute stated:

    We applaud the reasons for the proposal, as stated by OSHA: (a) 
To reflect the most current practice and technology in the industry; 
and (b) to respond to requests from stakeholders that the electrical 
standards conform with the most recent editions of the National Fire 
Protection Association (NFPA) 70E, Standard for Electrical Safety 
Requirements for Employee Workplaces, and the National Electrical 
Code (NEC). However, the proposal follows the NFPA standard 70E-
2000, while the NFPA Standards Council issued an updated version 
January 14, 2004, which supercedes NFPA 70E-2000. We believe that if 
the intent is to reflect the most current practice and technology, 
using a four-year-old standard, which will be even more dated by the 
time OSHA finalizes this standard, is inappropriate. We therefore 
recommend that OSHA revise the proposal using NFPA 70E-2004, 
Standard for Electrical Safety in the Workplace, or the 2002 NEC, 
which would require numerous modifications [Ex. 4-11].

    John Paschal of the Bechtel Corporation wrote: "Since NFPA 70E-
2004 is now published and issued to the public, and since it contains 
significantly enhanced technical data that the NFPA 70E-2000 did not 
contain, I recommend that OSHA adopt NFPA 70E-2004 instead of NFPA 70E-
2000 [Ex. 4-3]."
    James Kendrick of ASSE noted that the major differences between the 
current versions of the OSHA electrical installation standards and the 
proposed rule fall into the following categories:
     Changes in the hardware specifications that are consistent 
with NEC requirements,
     Changes in installation practices that are consistent with 
the current, accepted installation practices followed by licensed 
electricians and other qualified persons,
     Clarification of existing requirements that add minimal 
new obligations or otherwise permit flexibility in compliance, and
     Requirements that do significantly modify electrical 
system and equipment installation practices or impose new documentation 
requirements (Ex. 3-5).
    He was concerned that the OSHA final rule would be functionally 
obsolete when it is published and, thus, have diminished utility in the 
future since most electricians are currently learning the NEC 2002 
coding system. He argued that it would be beneficial for OSHA to use 
the same standard as those involved in electrical work.
    OSHA has decided not to base the final rule as a whole on NFPA 70E-
2004, which was published on April 9, 2004, shortly after OSHA's 
proposal was published. The 2004 version of the national consensus 
standard was not placed in the rulemaking record; therefore, the Agency 
does not believe that the public would have had adequate notice of the 
many changes in the latest NFPA standard, to the extent that the Agency 
would have incorporated these changes in the final rule. Basing Subpart 
S on the latest edition of NFPA 70E would thus necessitate reproposing 
the rule. Given the time involved in reproposing and finalizing an OSHA 
standard, it is likely that NFPA 70E will be revised yet again within 
that timeframe. In addition, because NFPA 70E and OSHA's electrical 
installation standard were developed specifically to minimize the need 
for revision with every new version of the NEC, a final rule based on 
the 2000 edition of NFPA 70E will not be obsolete. Furthermore, several 
provisions in the final rule are based on corresponding requirements in 
the 2002 NEC, on which NFPA 70E-2004 is based. (See the distribution 
table later in this section of the preamble.) In proposing and 
finalizing this revision of Subpart S, OSHA carefully chose which NEC 
changes would have the greatest impact on employee safety. The Agency 
does not believe that delaying the substantial increase in employee 
safety that would result from the standard published in the final rule 
is warranted.
    On the other hand, where the rulemaking record supports specific 
requirements that are consistent with the 2004 edition of NFPA 70E, 
OSHA has adopted those requirements in the final rule. For example, 
final Sec.  1910.304(b)(3)(ii)(A) is based, in part, on Section 
410.4(B)(1) of the 2004 edition of NFPA 70E rather than Part I, Chapter 
2, Section 2.4 of the 2000 edition of NFPA 70E. (See the detailed 
explanation, later in the preamble, discussing the rationale for this 
provision, which requires a written assured equipment grounding 
conductor program where ground-fault circuit-interrupters are not 
available.) In these specific cases, the rulemaking record supports 
OSHA's using the language from the relevant provision in NFPA 70E-2004 
and from the 2002 NEC, on which the new NFPA 70E requirement is based. 
This avoids the notice problem discussed earlier. In addition, OSHA 
will consider using later versions of NFPA 70E to update the electrical 
installation requirements adopted in this final rule when the Agency 
develops future proposals to revise Subpart S to update the existing 
electrical safety-related work practice requirements and to adopt new 
provisions on safety-related maintenance and special equipment.
    3. OSHA should update the Electrical Standard for construction at 
the same time this rule is being promulgated. The Agency received one 
comment asking OSHA to consider revising the Electrical Standard for 
construction at the same time as the revision to the Electrical 
Standard for general industry (Ex. 4-2). Reliable Safety Solutions, 
LLC, stated that installing equipment in general industry and 
installing equipment in the construction industry is much the same (Ex. 
4-2). They argued that the hazards encountered are the same and the 
safe work practices when working with electricity are the same. Thus, 
they said that to update one standard and not the other would allow for 
one standard to be out of date and certain hazards to exist.
    The Agency is aware that the general industry and the construction 
industry both address similar electrical hazards and have similar safe 
work practices. OSHA is also aware that its electrical standards for 
construction in 29 CFR 1926, Subpart K also need updating. Like Subpart 
S, Subpart K is based on the 1979 edition of NFPA 70E. In addition, the 
electrical safety-related work practices in Subpart K are even older 
than their general industry counterparts. However, OSHA must consult 
with the Advisory Committee on Construction Safety and Health before 
publishing a proposal. In addition, OSHA would have to include the 
construction industry in its regulatory analysis and repropose the 
standard to address construction as part of this rulemaking. Although 
OSHA will consider updating Subpart K to make it consistent with 
Subpart S in the future, it is not possible to do so as part of this 
final rule.
    4. OSHA should update the safety-related work practice requirements 
in Subpart S at the same time this rule is being promulgated. One 
commenter recommended that OSHA revise its electrical safety-related 
work practice standard in Subpart S based on the corresponding 
requirements in NFPA 70E (Ex. 4-5). He argued that electricians 
encounter exposed energized parts of electric circuits, which 
demonstrates the need for the protective clothing and safe work 
practices contained in NFPA 70E.
    OSHA agrees that the latest editions of NFPA 70E provide improved 
protection to employees through better electrical safety-related work 
practices. In particular, the heightened focus on the hazards posed by 
electric arcs may substantially reduce injuries and fatalities 
associated with those hazards. However, revising the safety-related 
work practice requirements in Subpart S is beyond the scope of this 
rulemaking. The Agency is planning to update these requirements as the 
next phase of the project to update OSHA's electrical standards. 
Although OSHA expects this phase of the project to yield significant 
benefits, the Agency also expects it to take longer to promulgate a 
final rule on safety-related work practices owing to the more complex 
regulatory analysis required and the greater controversy that is likely 
to be encountered.

B. Scope

    Existing Sec. Sec.  1910.302 through 1910.308 of Subpart S apply to 
electrical installations and utilization equipment used and installed 
in workplaces in general industry and in shipyard employment, 
longshoring, and marine terminals. These sections do not apply to the 
following types of installations:
    (1) Installations in ships, watercraft, railway rolling stock, 
aircraft, or automotive vehicles other than mobile homes and 
recreational vehicles;
    (2) Installations underground in mines; \5\
---------------------------------------------------------------------------

    \5\ This exception was incorporated into the current OSHA 
standard to be consistent with language used in the NEC and NFPA 
70E. However, it should be noted that OSHA does not have 
jurisdiction over mines in general, regardless of whether the mining 
activity takes place above ground or underground. Under the Mine 
Safety and Health Act (MSH Act) (30 U.S.C. 801 et seq.), the Mine 
Safety and Health Administration (MSHA) regulates safety and health 
in mines. For further information, see the Interagency Agreement 
between MSHA and OSHA (http://www.osha.gov/pls/oshaweb/owadisp.show_document?
p_table=MOU&p_id=222).
---------------------------------------------------------------------------

    (3) Installations of railways for generation, transformation, 
transmission, or distribution of power used exclusively for operation 
of rolling stock or installations used exclusively for signaling and 
communication purposes;
    (4) Installations of communication equipment under the exclusive 
control of communication utilities and located outdoors or in building 
spaces used exclusively for such installations; and
    (5) Installations under the exclusive control of electric utilities 
for the purpose of communication or metering; or for the generation, 
control, transformation, transmission, and distribution of electric 
energy. These exempted installations must be located in buildings used 
exclusively by utilities for such purposes or located outdoors on 
property owned or leased by the utility or on public highways, streets, 
roads, etc., or outdoors by established rights on private property.
    These exempted installations present special design considerations 
that are not adequately addressed in Subpart S. For example, electric 
power transmission and distribution installations are typically 
installed where unqualified persons will not have access to them, and 
the only employees working on them are highly trained and skilled. 
Additionally, public safety considerations demand that these 
installations be capable of quick repair when weather or equipment 
failure disrupts electrical service. The National Electrical Safety 
Code (ANSI/IEEE C2), which is developed by experts in electric power 
generation, transmission, and distribution, contains design and 
installation requirements applicable to electric power generation, 
transmission, and distribution systems. Section 1910.269 contains 
OSHA's standard for the maintenance of electric power generation, 
transmission, and distribution installations. While it consists mostly 
of work-practice requirements, it does contain several installation 
requirements. For example, Sec.  1910.269(u)(4) and (v)(4) cover 
guarding of rooms containing electric supply equipment in electric 
power generating stations and substations, respectively.
    Installations in ships, watercraft, railway rolling stock, 
aircraft, or automotive vehicles (other than mobile homes and 
recreational vehicles) are designed to be transportable.\6\ These 
transportability considerations make many of the design requirements in 
Subpart S irrelevant or infeasible. For example, attaching the grounded 
circuit conductor and the equipment grounding conductor to a permanent 
grounding electrode on a transportable wiring system is generally not 
feasible. Thus, some of the provisions in final Sec.  1910.304(g), 
which contains requirements for grounding electrical systems, are 
inappropriate for the wiring of ships, watercraft, railway rolling 
stock, aircraft, or automotive vehicles. By contrast, however, wiring 
that is not a part of the wiring of the ship, watercraft, railway 
rolling stock, aircraft, or automotive vehicle would be covered by 
Subpart S, as appropriate. For example, a portable electric drill 
carried into the cargo area of a truck would be covered by Subpart S if 
it is plugged into the wiring of a service station.
---------------------------------------------------------------------------

    \6\ Although the wiring of recreational vehicles and mobile 
homes is transportable, it is also designed to be attached to 
specially designed, permanently installed power distribution 
outlets. This type of hybrid system must be designed for both 
permanent and transportable uses.
---------------------------------------------------------------------------

    In regard to ships, there has been some confusion about whether the 
"exemption" applies to all wiring or electrical installations brought 
on board a vessel during construction, repair, or ship scrapping even 
when the wiring is supplied by shore-based electric power--or whether 
it only applies to the ship's own wiring. OSHA is hereby clarifying the 
application of the exemptions.
    The "exempted" types of installations in both the existing and 
final standards are identical to those "exempted" by the NEC and NFPA 
70E, which form the basis of both standards. Installations covered 
under the existing standard continue to be covered under the final 
standard. For example, in longshoring operations and related 
employments, this final rule applies to electrical installations aboard 
vessels only if they are shore-based as stated in Sec.  1918.1(b)(3). 
Electrical installations in marine terminals are also covered under 
Subpart S, as noted in Sec.  1917.1(a)(2)(iv). (The marine terminals 
standard in Part 1917 applies to the loading, unloading, movement or 
other handling of cargo, ship's stores or gear within the terminal or 
into or out of any land carrier, holding or consolidation area, and any 
other activity within and associated with the overall operation and 
function of the terminal. This includes the use and routine maintenance 
of facilities and equipment and cargo transfer accomplished with the 
use of shore-based material handling devices. See Sec.  1917.1(a).)
    Section 1910.5 governs how the general industry standards apply to 
shipyard employment. According to Sec.  1910.5(c), the general 
standards in Part 1910 apply to shipyard employment to the extent that 
no industry-specific standard applies to the "same condition, 
practice, means, method, operation, or process." Part 1915 contains 
few requirements related to electrical safety. Paragraph (b) of Sec.  
1915.93 contains four such requirements, for grounding of vessels, the 
safety of the vessel's wiring, overcurrent protection, and guarding of 
infrared heat lamps. Section 1915.92 contains provisions on temporary 
electric lighting, and Sec.  1915.132 contains requirements on portable 
electric tools. Section 1915.181 contains electrical safety-related 
work practices for deenergizing electric circuits and protecting 
employees against contact with live parts during electrical work. In 
addition, Part 1915 contains several other miscellaneous electrical 
safety-related work practices and electrical design requirements. These 
provisions continue to apply in lieu of any corresponding requirements 
in Subpart S of Part 1910. Conversely, where there is no specific 
electrical installation requirement for shipyard employment in Part 
1915, Subpart S of Part 1910 applies.
    As noted earlier, Subpart S does not cover installations in ships, 
but it does cover installations used on ships if the installation is 
shore-based (that is, not part of the vessel's original, internal 
electrical system). Thus, final Sec.  1910.303(g)(2) (guarding live 
parts) applies to the shore-based wiring of the shipyard and to any 
wiring taken onto the ship when it is supplied by shore-based wiring. 
It does not apply to the ship's permanent wiring. The final rule does 
not change this coverage.

C. Grandfather Clause

    The final rule, as does the current standard, exempts older 
electrical installations from meeting some of the provisions of the 
Design Safety Standards for Electrical Systems (that is, Sec. Sec.  
1910.302 through 1910.308). The extent to which OSHA's electrical 
installation standard applies depends on the date the installation was 
made. Older installations must meet fewer requirements than newer ones. 
The grandfathering of older installations, contained in paragraph (b) 
of final Sec.  1910.302, is patterned after the current standard's 
grandfather provisions in existing Sec.  1910.302(b). Most of the new 
provisions contained in the final rule only apply prospectively, to 
installations made after the effective date of the final rule.
    The following paragraphs explain final Sec.  1910.302(b) in the 
following order: Paragraph (b)(1), requirements applicable to all 
installations; paragraph (b)(4), requirements applicable only to 
installations made after the effective date of the revised standard; 
paragraph (b)(3), requirements applicable only to installations made 
after April 16, 1981; and paragraph (b)(2), requirements applicable 
only to installations made after March 15, 1972.
    Requirements applicable to all installations. Paragraph (b)(1) of 
final Sec.  1910.302 contains a list of provisions that would apply to 
all installations, regardless of when they were designed or installed. 
The few requirements in this short list are so essential to employee 
safety that even the oldest electrical installations must be modified, 
if necessary, to meet them. The list is unchanged from the current 
standard, except for the addition of: a prohibition on using grounding 
terminals and devices for purposes other than grounding (in final
Sec.  1910.304(a)(3)); a documentation requirement for hazardous 
locations made under the zone classification system (in final Sec.  
1910.307(b)); and requirements covering the zone classification system 
(in final Sec.  1910.307(g)).
    New provisions applicable to all installations. Paragraph (a)(3) of 
Sec.  1910.304 prohibits the use of a grounding terminal or grounding-
type device on a receptacle, cord connector, or attachment plug for 
purposes other than grounding. OSHA's reasons for adding this 
requirement to the list of provisions applicable to all installations 
is discussed later in this section of the preamble.
    Paragraph (b) of final Sec.  1910.307 contains a new requirement 
that employers document areas designated as hazardous (classified) 
locations. This requirement would ensure that the employer has records 
of the extent and classification of each such area. The documentation 
will help employers to determine what type of equipment is needed in 
these locations and will inform employees of the need for special care 
in the maintenance of the electric equipment installed there. OSHA has 
carefully considered the need to document these areas and has tried to 
balance that need with the extensive burden that would be placed on 
employers who would have to survey and document their existing 
hazardous locations.
    The current standard's division classification system has been in 
place for many years, and most employers and inspection authorities are 
familiar with the boundaries for Class I, II, and III, Division 1 and 2 
locations. An employee servicing equipment in one of these locations 
can obtain this information relatively easily even if the employer has 
not documented the boundaries. Accordingly, OSHA believes that the 
benefit of documenting existing hazardous locations installed using the 
division classification system would be minimal. Therefore, for 
employers using the division system, OSHA is requiring documentation of 
boundaries only for new installations made after the effective date of 
the final standard. Employers would not need to document existing 
division-classified systems.
    On the other hand, the zone classification system is relatively 
new. Most employers are not familiar with this system and have little 
experience determining how to draw the boundaries between the three 
zones. Relatively few NFPA or industry standards provide specifications 
for placing those boundaries. Furthermore, the existing OSHA electrical 
standard recognizes only installations made in accordance with the 
division classification system, not the zone classification system. Any 
existing installation made under the zone system is technically out of 
compliance with OSHA's existing standard. However, because the NEC 
represents standard industry practice, existing zone system 
installations will almost certainly have been installed in accordance 
with an edition of the NEC that recognizes the zone classification 
system (the 1999 and 2002 editions). These editions of the NEC 
explicitly require documentation of hazardous locations. Thus, an 
employer with an existing installation made under the zone 
classification system should already have the documentation required by 
final Sec.  1910.307(b). For these reasons, OSHA is applying the 
documentation requirement to all hazardous location installations made 
under the zone classification system. This will provide employers, 
employees, and OSHA with information critical for determining which 
equipment is suitable in a given hazardous location.
    The new requirements pertaining to zone classification in final 
Sec.  1910.307(g) provide employers with an alternative installation 
method that the current standard does not permit.\7\ Thus, applying 
these provisions to older installations would give employers greater 
flexibility without imposing any new costs. Furthermore, to the extent 
that employers are already using the zone classification system, those 
employers are likely already meeting final Sec.  1910.307(g), which is 
based on provisions in the 1999 and 2002 editions of the NEC.
---------------------------------------------------------------------------

    \7\ See the discussion under the heading "Zone Classification" 
for an explanation of the zone classification system and its 
differences from the current standard's division classification 
system.
---------------------------------------------------------------------------

    Requirements applicable only to installations made after the 
effective date of the final rule. Paragraph (b)(4) of final Sec.  
1910.302 makes the following provisions applicable only to 
installations made or overhauled \8\ after the effective date of the 
final rule:
---------------------------------------------------------------------------

    \8\ See the discussion of the term "overhaul" later in this 
section of the preamble.

------------------------------------------------------------------------

------------------------------------------------------------------------
Sec.   1910.303(f)(4)..................  Disconnecting means and
                                          circuits--Capable of accepting
                                          a lock.
Sec.   1910.303(f)(5)..................  Disconnecting means and
                                          circuits--Marking for series
                                          combination ratings.
Sec.   1910.303(g)(1)(iv) and            600 Volts, nominal, or less--
 (g)(1)(vii).                             Space about electric
                                          equipment.
Sec.   1910.303(h)(5)(vi)..............  Over 600 volts, nominal--
                                          Working space and guarding.
Sec.   1910.304(b)(1)..................  Branch circuits--Identification
                                          of multiwire branch circuits.
Sec.   1910.304(b)(3)(i)...............  Branch circuits--Ground-fault
                                          circuit interrupter protection
                                          for personnel.
Sec.   1910.304(f)(2)(i)(A),             Overcurrent protection--Feeders
 (f)(2)(i)(B) (but not the introductory   and branch circuits for over
 text to Sec.   1910.304(f)(2)(i)), and   600 volts, nominal.
 (f)(2)(iv)(A).
Sec.   1910.305(c)(3)(ii)..............  Switches--Connection of
                                          switches.
Sec.   1910.305(c)(5)..................  Switches--Grounding.
Sec.   1910.306(a)(1)(ii)..............  Electric signs and outline
                                          lighting--Disconnecting means.
Sec.   1910.306(c)(4)..................  Elevators, dumbwaiters,
                                          escalators, moving walks,
                                          wheelchair lifts, and stairway
                                          chair lifts--Operation.
Sec.   1910.306(c)(5)..................  Elevators, dumbwaiters,
                                          escalators, moving walks,
                                          wheelchair lifts, and stairway
                                          chair lifts--Location.
Sec.   1910.306(c)(6)..................  Elevators, dumbwaiters,
                                          escalators, moving walks,
                                          wheelchair lifts, and stairway
                                          chair lifts--Identification
                                          and signs.
Sec.   1910.306(c)(7)..................  Elevators, dumbwaiters,
                                          escalators, moving walks,
                                          wheelchair lifts, and stairway
                                          chair lifts--Single-car and
                                          multicar installations.
Sec.   1910.306(j)(1)(iii).............  Swimming pools, fountains, and
                                          similar installations--
                                          Receptacles.
Sec.   1910.306(k).....................  Carnivals, circuses, fairs, and
                                          similar events.
Sec.   1910.308(a)(5)(v) and             Systems over 600 volts,
 (a)(5)(vi)(B).                           nominal--Interrupting and
                                          isolating devices.
Sec.   1910.308(a)(7)(vi)..............  Systems over 600 volts,
                                          nominal--Tunnel installations.
Sec.   1910.308(b)(3)..................  Emergency power systems--Signs.
Sec.   1910.308(c)(3)..................  Class 1, Class 2, and Class 3
                                          remote control, signaling, and
                                          power-limited circuits--
                                          Separation from conductors of
                                          other circuits.
Sec.   1910.308(f).....................  Solar photovoltaic systems.
------------------------------------------------------------------------

    These provisions are based on requirements that have been added to 
the NEC since the 1978 edition. OSHA has never required employers to 
comply with these requirements, and the Agency believes that an 
increase in employee protection will result from compliance with them 
in new installations. At the same time, employers would incur minimal 
costs to achieve this increase in new installations. In local 
jurisdictions requiring compliance with the NEC, there should be no 
additional costs involved, because the installations would already 
conform to the new OSHA requirements. The Agency believes that even in 
other jurisdictions, the vast majority of installations already comply 
with the latest edition of the NEC, because compliance with the latest 
Code is standard industry practice. OSHA, however, does not believe 
that it is reasonably necessary and appropriate to require existing 
installations to conform to these provisions, particularly given the 
cost and difficulty associated with retrofitting older installations.
    There are many provisions in the final rule that are not contained 
in the existing standard but cannot be considered totally "new" 
provisions. Most of these "new" requirements were actually contained 
in the 1971 NEC. Table 1 lists these "new" provisions and denotes 
their counterparts in the 1971 NEC. From March 15, 1972, until April 
16, 1981, Subpart S incorporated the 1971 NEC by reference in its 
entirety. Accordingly, OSHA required employers to comply with every 
requirement in the 1971 NEC for any new installation made between those 
dates and for any replacement, modification, repair, or rehabilitation 
made during that period. The current standard, which became effective 
on April 16, 1981, omitted many of the detailed provisions of the NEC 
because they were already addressed by the more general requirements 
that were contained in the OSHA standard. For example, OSHA did not 
carry forward 1971 NEC Section 110-11, which required equipment to be 
suitable for the environment if it is installed where the environment 
could cause deterioration. However, the requirement for equipment to be 
suitable for the location in which it was installed is implicit in the 
more general requirements in existing Sec.  1910.303(a) that equipment 
be approved and in existing Sec.  1910.303(b)(2) that equipment be 
installed in accordance with any instructions included in its listing 
or labeling. (Equipment that is not suitable for installation in 
deteriorating environments, such as wet or damp locations, will include 
instructions warning against such installation. These instructions are 
required by the nationally recognized testing laboratory listing or 
labeling the product.)
    Even though OSHA no longer specifically incorporates the 1971 NEC 
into Subpart S, the Agency believes that employers' installations 
actually do comply with those requirements. The vast majority of 
employers are following the entire NEC applicable to their 
installations, as noted in the Economic Analysis section of this 
preamble.\9\ For these reasons, OSHA is not exempting installations 
made after March 15, 1972, from meeting any provision listed in Table 1 
and is not including any of these provisions in final Sec.  
1910.302(b)(4) (the list of provisions that apply only to new 
installations).
---------------------------------------------------------------------------

    \9\ All of the requirements in question appear in some form in 
every edition of the NEC since 1972.
    \10\ These provisions have no direct counterpart in existing 
Subpart S, but were in the 1971 National Electrical Code.

    Table 1.--"New" Provisions That Were Contained in 1971 NEC \10\
------------------------------------------------------------------------
    Provision in the final       Equivalent 1971
           standard                NEC section            Subject
------------------------------------------------------------------------
Sec.   1910.303(b)(3).........  110-20...........  Insulation integrity.
    (b)(4)....................  110-9............  Interrupting rating.
    (b)(5)....................  10-10............  Circuit impedance and
                                                    other
                                                    characteristics.
    (b)(6)....................  110-11...........  Deteriorating agents.
    (b)(7)....................  110-12...........  Mechanical execution
                                                    of work.
    (b)(8)....................  110-4(a) and (d).  Mounting and cooling
                                110-12...........   of equipment.
                                110-13...........
    (c)(1)....................  110-14...........  Electrical
                                                    connections,
                                                    general.
Sec.   1910.304(b)(2).........  210-21(b)........  Branch circuits,
                                                    receptacles and cord
                                                    connectors.
    (b)(4)....................  210-21...........  Branch circuits,
                                                    outlet devices.
    (b)(5)....................  210-22...........  Branch circuits, cord
                                                    connections.
    (e)(1)(iii)...............  230-70(c)........  Services,
                                                    disconnecting means.
    (f)(1)(ix)................  110-9............  Overcurrent
                                240-11...........   protection, 600
                                                    volts, nominal, or
                                                    less, circuit
                                                    breaker ratings.
    (f)(2), except for          240-5............  Overcurrent
     (f)(2)(i)(A),              240-11...........   protection, feeders
     (f)(2)(i)(B), and          240-15...........   and branch circuits
     (f)(2)(iv)(A).                                 over 600 volts,
                                                    nominal.
Sec.   190.305(a)(4)(ii)......  320-5............  Open wiring on
                                                    insulators, support.
    (b)(1)(iii)...............  370-7............  Conductors entering
                                373-5............   cabinets, boxes, and
                                                    fittings, securing
                                                    conductors.
    (b)(2)(ii)................  370-15(b)........  Fixture canopy or pan
                                                    installed in a
                                                    combustible wall or
                                                    ceiling.
    (e)(1)....................  373-2............  Airspace for
                                384-5............   enclosures installed
                                                    in wet or damp
                                                    locations.
    (h)(3)....................  710-6............  Portable cables,
                                                    grounding
                                                    conductors.
    (j)(2)(i).................  410-52(d)........  Receptacles, cord
                                                    connectors, and
                                                    attachment plugs; no
                                                    exposed energized
                                                    parts.
    (j)(2)(iv) through          410-54...........  Receptacles installed
     (j)(2)(vii).                                   in wet or damp
                                                    locations.
    (j)(3)(ii)................  422-20...........  Appliances,
                                                    disconnecting means.
    (j)(3)(iii)...............  422-30(a)........  Appliances,
                                                    nameplates.
    (j)(3)(iv)................  422-30(b)........  Appliances, marking
                                                    to be visible after
                                                    installation.
    (j)(6)(ii)(A).............  110-9............  Capacitor switches.
                                110-10...........
                                460-8(c)(4)......
    (j)(6)(ii)(B).............  460-8(c)(1)......  Capacitor
                                                    disconnecting means.
Sec.   1910.306(c)(3).........  620-51(a)........  Elevators,
                                                    dumbwaiters,
                                                    escalators, moving
                                                    walks, wheelchair
                                                    lifts, and stairway
                                                    chair lifts; type of
                                                    disconnecting means.
    (c)(10)...................  620-72...........  Elevators,
                                                    dumbwaiters,
                                                    escalators, moving
                                                    walks, wheelchair
                                                    lifts, and stairway
                                                    chair lifts; motor
                                                    controllers.
    (d)(1)....................  630-13...........  Arc welders,
                                630-23...........   disconnecting means.
    (g)(1)(iii)...............  665-34...........  Induction and
                                                    dielectric heating
                                                    equipment,
                                                    detachable panels
                                                    used for access to
                                                    live parts.
    (g)(1)(vi)................  665-8............  Induction and
                                                    dielectric heating
                                                    equipment, ampere
                                                    rating of
                                                    disconnecting means.
    (j)(4)(iii)...............  680-20(a)(4).....  Swimming pools,
                                                    fountains, and
                                                    similar
                                                    installations,
                                                    underwater fixtures
                                                    facing upwards.
Sec.   1910.308(a)(2).........  710-4............  Systems over 600
                                                    volts, nominal; open
                                                    installations of
                                                    braid-covered
                                                    insulated
                                                    conductors.
    (a)(3)(i).................  710-6............  Systems over 600
                                                    volts, nominal;
                                                    insulation shielding
                                                    terminations.
    (a)(4)....................  710-8............  Systems over 600
                                                    volts, nominal;
                                                    moisture or
                                                    mechanical
                                                    protection for metal-
                                                    sheathed cables.
    (a)(5)(i).................  710-21(a)........  Systems over 600
                                                    volts, nominal;
                                                    interrupting and
                                                    isolating devices;
                                                    guarding and
                                                    indicating.
    (a)(5)(ii)................  240-11(a)........  Systems over 600
                                710-21(b)........   volts, nominal;
                                                    interrupting and
                                                    isolating devices;
                                                    fuses.
    (a)(5)(iii) and (a)(5)(iv)  710-21(b)........  Systems over 600
                                                    volts, nominal;
                                                    interrupting and
                                                    isolating devices;
                                                    fused cutouts.
    (a)(5)(vi), but not         710-21(c)........  Systems over 600
     (a)(5)(vi)(B).                                 volts, nominal;
                                                    interrupting and
                                                    isolating devices;
                                                    load interrupter
                                                    switches.
    (a)(5)(vii)...............  710-22...........  Systems over 600
                                                    volts, nominal;
                                                    interrupting and
                                                    isolating devices;
                                                    means for isolating
                                                    equipment.
    (b)(2)....................  700-14...........  Emergency systems,
                                                    emergency
                                                    illumination.
------------------------------------------------------------------------

    In addition, OSHA is not including in the list of new provisions in 
final Sec.  1910.302(b)(4) any provision that merely provides an 
alternative means of compliance for an existing requirement. For 
example, as noted earlier, final Sec.  1910.307(g) provides alternative 
requirements for installations in hazardous (classified) locations 
based on the zone classification system rather than the division 
classification system that is required under the existing standard. 
Such requirements accept alternative installation techniques recognized 
as being equally protective by the NEC and NFPA 70E, and there is no 
need to limit them to new installations.
    OSHA also believes that there is no need to grandfather 
requirements that apply only to temporarily installed equipment and 
wiring.\11\ The few new requirements applying to temporarily installed 
equipment and wiring have been in the NEC since at least 1999 and, in 
most cases, since before that. Employers should already be in 
compliance with such requirements since any existing temporary 
installations almost certainly were put into place well after 1999.\12\ 
For example, final Sec.  1910.304(b)(3)(ii) contains requirements for 
providing ground-fault circuit interrupter protection for temporary 
wiring installations that are used during maintenance, remodeling, or 
repair of buildings, structures, or equipment or during similar 
activities. Temporary wiring installations used for any of these 
purposes were likely to have been installed well after 1999. An 
employer who is complying with the 1999 or later edition of the NEC 
will already be complying with this provision of the rule. Even 
employers who are not complying with recent versions of the NEC for 
temporary wiring installations will face, in this example, only the 
minimal cost of providing ground-fault circuit interrupters; no changes 
would need to be made to any existing permanent wiring, which might 
involve considerably more costs.
---------------------------------------------------------------------------

    \11\ For the purposes of this discussion, "temporarily 
installed equipment or wiring" is wiring and equipment installed on 
a short-term rather than a long-term or permanent basis. It includes 
temporary wiring covered by proposed Sec.  1910.305(a)(2) and other 
equipment and wiring similarly installed on a short-term basis.
    \12\ The limit for temporary wiring used for Christmas 
decorative lighting, carnivals, and similar purposes is 90 days 
(Sec.  1910.305(a)(2)(i)(B)). For other purposes, such as remodeling 
and repair, the limit is the duration of the activity. However, OSHA 
believes that it is highly unlikely that any particular temporary 
activity covered by Subpart S has been on-going since 1999.
---------------------------------------------------------------------------

    Requirements applicable only to installations made after April 16, 
1981. Paragraph (b)(3) of final Sec.  1910.302 lists requirements that 
apply only to installations made after April 16, 1981.
This paragraph carries forward essentially the same list as is 
currently in Sec.  1910.302(b)(3). No provisions have been added to or 
removed from the list.
    Requirements applicable only to installations made after March 15, 
1972. Paragraph (b)(2) of existing Sec.  1910.302 requires all 
installations made after March 15, 1972, and every major replacement, 
modification, repair, or rehabilitation made after that date to meet 
all the installation requirements in Subpart S except for those listed 
in existing Sec.  1910.302(b)(3). A note following existing Sec.  
1910.302(b)(2) indicates that " `[m]ajor replacements, modifications, 
repairs, or rehabilitations' include work similar to that involved when 
a new building or facility is built, a new wing is added, or an entire 
floor is renovated."
    Paragraph (b)(2) of final Sec.  1910.302 will require all 
installations built or overhauled after March 15, 1972, to comply with 
all of the requirements of final Sec. Sec.  1910.302 through 1910.308, 
except as provided in final Sec.  1910.302(b)(3) and (b)(4). As 
discussed earlier, these latter two paragraphs limit the application of 
newer provisions of Subpart S to installations made during later 
periods.
    In Sec.  1910.302(b)(2) in the final rule, OSHA is introducing the 
term "overhaul" to include the types of activities that would trigger 
compliance with the otherwise grandfathered provisions of Subpart S for 
older installations. In Sec.  1910.399 of the final rule, "overhaul" 
is defined as follows:

    Overhaul means to perform a major replacement, modification, 
repair, or rehabilitation similar to that involved when a new 
building or facility is built, a new wing is added, or an entire 
floor is renovated.

    This new term incorporates all the elements of "major replacement, 
modification, or rehabilitation" in the text of existing Sec.  
1910.302(b)(2) and in the note following that provision. OSHA believes 
that using and defining the term "overhaul" in the final rule will 
simplify the standard without making any substantive change to the way 
in which Subpart S applies to older installations.
    Comments on the grandfather clause. OSHA received several comments 
on the grandfather clause proposed in Sec.  1910.302(b) (Exs. 3-7, 4-
25). One commenter was concerned about the level of cross-referring an 
employer would need to do to determine what standards are applicable to 
a given installation (Ex. 3-7). He recommended that a simpler approach 
be adopted or that OSHA develop guidance materials to help employers 
determine which requirements apply to installations made during each of 
the periods addressed by the grandfather clause. Neither commenter 
proposed language that might accomplish this.
    While OSHA acknowledges that some commenters believe that this 
clause is too complex, the Agency believes that the approach taken in 
the final standard is as simple as the Agency can make it. However, 
OSHA will provide compliance assistance tools that will help employers 
understand which requirements are applicable to their particular 
electrical installations. For example, the Agency is considering 
providing on the OSHA Website a color-coded version depicting 
requirements with different applicability dates with different colors 
or a version that lets the reader input the date of the installation 
and that hides inapplicable provisions. Such tools should enable 
employers to determine their compliance obligations quickly and easily. 
In addition, for questions about compliance with the standard, 
employers can contact OSHA through its toll-free telephone help line at 
1-800-321-6742. Alternatively, employers can contact the OSHA Area 
Office or State Plan office nearest them.
    Paragraph (b)(4) of final Sec.  1910.302 lists Sec.  
1910.304(b)(3)(i) (proposed Sec.  1910.304(b)(4)(i)), which requires 
ground-fault circuit interrupter protection for certain permanently 
installed receptacle outlets, as a provision that only applies to new 
installations. One commenter recommended that all of proposed Sec.  
1910.304(b)(4), which as noted previously contains requirements for 
ground-fault circuit interrupters on temporary receptacle outlets, 
apply only to new installations (Ex. 3-7). The commenter noted that 
this provision is new and should only be applied to new installations.
    As noted earlier, OSHA believes that most employers are already 
complying with this provision. The National Electrical Code has 
required ground-fault circuit interrupters in a manner similar to that 
in the final rule since the 1996 edition of the NEC. In addition, the 
final rule sets an effective date 180 days after publication of the 
final rule in the Federal Register. OSHA believes that very few 
temporary installations that were in place before publication of the 
final rule will still be in place 6 months later. There may be some 
projects using temporary wiring that last more than 6 months, 
particularly in shipyards. However, even there, OSHA believes that 
temporary receptacle outlets will be moved around, installed, 
uninstalled, and reinstalled many times over the life of the project. 
Even if the Agency were to apply final Sec.  1910.304(b)(3)(ii) only to 
installations made after the effective date, it would apply as soon as 
a receptacle outlet was installed (or reinstalled). OSHA does not 
believe that there is a compelling reason to exempt the very few 
remaining temporary receptacle outlets that may still be in place after 
the effective date. Therefore, OSHA has not adopted the commenter's 
recommendation.
    Mr. Pat Kimmet of CHS Inc. and Mr. Rick Leicht of NCRA were 
concerned that provisions listed in proposed Sec.  1910.302(b)(1), 
which were to apply to all installations regardless of age, would 
require employers to examine existing installations for compliance and 
possibly replace noncompliant equipment even when no significant hazard 
exists (Ex. 4-25). They specifically objected to the inclusion of wire 
bending space (proposed Sec.  1910.303(b)(1)(iii)) on the list. They 
argued that this provision is a relatively recent addition to the NEC 
and that the NEC has revised the wire bending space requirements 
periodically. They believed that the proposal would have required 
employers to meet the wire bending space requirements in the 2000 
edition of the NFPA 70E and the 2002 edition of the NEC.
    OSHA believes that an installation that does not comply with the 
provisions listed in final Sec.  1910.302(b)(1) poses a significant 
hazard to employees. Furthermore, as noted earlier, almost all of the 
provisions listed in that paragraph applied to all installations 
regardless of age since March 15, 1972. Thus, employers should already 
be in compliance with nearly all of the listed provisions.
    The new provisions related to the zone classification system 
(including the documentation requirement) provide for an alternative 
compliance method to that required by the existing standard. The other 
new provision, the prohibition on using grounding terminals and devices 
for purposes other than grounding, as noted earlier, has been a long-
standing NEC requirement. Thus, OSHA does not believe that very many 
existing installations are in violation of this new provision. 
Consequently, Mr. Kimmet's and Mr. Leicht's general concerns about 
widespread noncompliance are unfounded.
    With respect to their specific concern with the inclusion of 
proposed Sec.  1910.303(b)(1)(iii) in the list of provisions applicable 
to all installations, OSHA notes that wire bending space, as mentioned 
in this provision, is simply one of several factors to be considered in 
judging electrical equipment for safety. Paragraph (b)(1) of final 
Sec.  1910.303 reads, in part, as follows:
    (b) Examination, installation, and use of equipment. (1) 
Examination. Electric equipment shall be free from recognized 
hazards that are likely to cause death or serious physical harm to 
employees. Safety of equipment shall be determined using the 
following considerations:
* * * * *
    (iii) Wire-bending and connection space;
* * * * *
    (viii) Other factors that contribute to the practical 
safeguarding of persons using or likely to come in contact with the 
equipment.

    Paragraph (b)(1)(iii) of final Sec.  1910.303 does not require 
compliance with the minimum wire bending space requirements in the NEC. 
Rather, wire bending space will be one of the relevant factors in 
judging the electrical safety of equipment in accordance with the 
introductory text of final Sec.  1910.303(b)(1). OSHA does not consider 
this a new requirement. The current standard contains the catchall 
"other factors" language in existing Sec.  1910.303(b)(1)(vii). The 
Agency construes wire bending space to be one of those "other 
factors" judged under the existing standard. Thus, OSHA is simply 
making explicit in the final rule a factor employers were required to 
consider under Sec.  1910.303(b)(1)(vii) of the existing standard. If 
conductors are installed so tightly into enclosures that they overheat 
or that the insulation is damaged, a serious safety hazard would exist. 
Such an installation would violate the existing standard as well as the 
new one. For these reasons, OSHA has not adopted Mr. Kimmet's and Mr. 
Leicht's recommendation to remove Sec.  1910.303(b)(1)(iii) from the 
list of provisions in final Sec.  1910.302(b)(1) that apply to all 
installations.
    Several commenters suggested that proposed Sec.  1910.304(a)(3) be 
added to the list of requirements in Sec.  1910.302(b)(1) applicable to 
all installations (Exs. 4-13, 4-17, 4-18, 4-21). Proposed Sec.  
1910.304(a)(3) read as follows:

    A grounding terminal or grounding-type device on a receptacle, 
cord connector, or attachment plug may not be used for purposes 
other than grounding.

    Mr. Bernie Ruffenach typified these commenters, reasoning as 
follows:

    The use of the grounding terminal(s) of any device has never 
been permitted in any electrical standards, codes or other 
recognized practices at any time. Typically, the use of the 
grounding terminal for other than grounding purposes is due to 
improper wiring and occurs when an ungrounded (hot) conductor is 
applied. The result is an imminent danger electrocution hazard. [Ex. 
4-17]

    OSHA agrees that using a grounding terminal or device for purposes 
other than grounding can present a hazard threatening imminent death or 
serious injury. For example, using a grounding terminal as the 
attachment point for a circuit conductor can energize the frame of 
equipment used by employees. If an employee was to touch such miswired 
equipment and a grounded surface at the same time, he or she would 
receive an electric shock and possibly die of electrocution. As the 
commenters noted, compliance with this provision has been a long-
standing common industry practice. Therefore, OSHA has adopted the 
suggestion of these commenters and has added Sec.  1910.304(a)(3) to 
the list of provisions in final Sec.  1910.302(b)(1) that are 
applicable to all installations.

D. Applicability of Requirements for Disconnecting Means

    Several provisions in the final standard require electrical 
disconnecting means to be capable of being locked in the open position 
under certain conditions. For example, final Sec.  1910.306(a)(2)(i) 
requires the disconnecting means for sign and outline lighting systems 
to be capable of being locked in the open position if they are out of 
the line of sight from any section that may be energized. These 
provisions ensure that employees servicing or maintaining the electric 
circuits supplied by the disconnecting means are protected against 
electric shock.
    Sometimes, these disconnecting means also serve as energy isolating 
devices as defined in paragraph (b) of Sec.  1910.147, OSHA's existing 
standard for the control of hazardous energy sources (lockout-tagout). 
Energy isolating devices physically prevent the transmission or release 
of energy. In the case of electric equipment, disconnecting means that 
meet the definition of energy isolating devices prevent the 
transmission of electric energy so that the equipment cannot start up 
and injure employees.
    Paragraph (c)(2)(iii) of the lockout-tagout standard reads as 
follows:

    After January 2, 1990, whenever replacement or major repair, 
renovation or modification of a machine or equipment is performed, 
and whenever new machines or equipment are installed, energy 
isolating devices for such machine or equipment shall be designed to 
accept a lockout device.

    Paragraph (c) of final Sec.  1910.302 clarifies that the provision 
in the lockout-tagout standard is in addition to any requirements in 
Subpart S for disconnecting means to be capable of being locked open. 
The requirements in Subpart S are intended for the protection of 
servicing and maintenance employees from electric shock, which is not 
covered by Sec.  1910.147. The lockout-tagout standard on the other 
hand addresses nonelectric-shock hazards related to servicing and 
maintaining equipment. Thus, the requirements of both standards are 
necessary to protect employees from all servicing- and maintenance-
related hazards.
    OSHA received no comments on this provision in the proposal, and it 
is being carried into the final rule without change.

E. Summary of Changes in Sec. Sec.  1910.303 Through 1910.308

    The Distribution Table for Subpart S lists all the provisions and 
sections from Sec. Sec.  1910.303 through 1910.308. This table 
summarizes changes being made to the standard that involve grammatical 
edits, additions, removals, and paragraph numbers. There are places in 
the standard where no substantial change is made. Most of the changes 
are editorial in nature. Substantive changes made to the existing 
standard are discussed in further detail following the Distribution 
Table.

                           Distribution Table
------------------------------------------------------------------------
                                                       Description of
         OLD--section              NEW--section    changes and rationale
------------------------------------------------------------------------
                  See the note at the end of the table.
------------------------------------------------------------------------
Sec.   1910.303 General.......  Sec.   1910.303
                                 General.
1910.303(a)...................  1910.303(a)......  No substantive
                                                    change. A reference
                                                    to the Sec.
                                                    1910.399 definition
                                                    of "approved" is
                                                    added for
                                                    clarification.
1910.303(b)(1), introductory    1910.303(b)(1),    No substantive
 text.                           introductory       change.
                                 text.
1910.303(b)(1)(i).............  1910.303(b)(1)(i)  No substantive
                                                    change.
1910.303(b)(1)(ii)............  1910.303(b)(1)(ii  No substantive
                                 ).                 change.
                                1910.303(b)(1)(ii  **Adds wire-bending
                                 i).                and connection space
                                                    to the explicit list
                                                    of things to
                                                    consider when
                                                    judging equipment.
1910.303(b)(1)(iii)...........  1910.303(b)(1)(iv  No substantive
                                 ).                 change.
1910.303(b)(1)(iv)............  1910.303(b)(1)(v)  No substantive
                                                    change.
1910.303(b)(1)(v).............  1910.303(b)(1)(vi  No substantive
                                 ).                 change.
1910.303(b)(1)(vi)............  1910.303(b)(1)(vi  No substantive
                                 i).                change.
1910.303(b)(1)(vii)...........  1910.303(b)(1)(vi  No substantive
                                 ii).               change.
1910.303(b)(2)................  1910.303(b)(2)...  No substantive
                                                    change.
                                1910.303(b)(3)...  **Adds a requirement
                                                    for completed wiring
                                                    to be free from
                                                    short circuits and
                                                    grounds other than
                                                    those required in
                                                    the standard.
                                1910.303(b)(4)...  **Adds requirements
                                                    for equipment
                                                    intended to
                                                    interrupt current to
                                                    have adequate
                                                    interrupting
                                                    ratings.
                                1910.303(b)(5)...  **Adds requirements
                                                    for the coordination
                                                    of overcurrent
                                                    protection for
                                                    circuits and
                                                    equipment.
                                1910.303(b)(6)...  **Adds a requirement
                                                    for conductors and
                                                    equipment to be
                                                    identified for the
                                                    purpose when
                                                    installed in an
                                                    environment
                                                    containing
                                                    deteriorating
                                                    agents.
                                1910.303(b)(7)...  **Adds requirements
                                                    for installing
                                                    electric equipment
                                                    in a neat and
                                                    workmanlike manner.
                                1910.303(b)(8)...  **Adds requirements
                                                    for equipment to be
                                                    mounted securely and
                                                    to allow for proper
                                                    cooling.
                                1910.303(c)(1)...  **Adds requirements
                                                    to ensure that
                                                    electrical
                                                    connections are
                                                    secure and
                                                    electrically safe.
                                1910.303(c)(2)...  **Adds requirements
                                                    for connections at
                                                    terminals and for
                                                    the identification
                                                    of terminals
                                                    intended for
                                                    connection to more
                                                    than one conductor
                                                    or to aluminum.
1910.303(c)...................  1910.303(c)(3)(i)  No substantive
                                                    change.
                                1910.303(c)(3)(ii  **Adds a requirement
                                 ).                 that wire connectors
                                                    or splicing means
                                                    installed on
                                                    directly buried
                                                    conductors be listed
                                                    for such use.
1910.303(d)...................  1910.303(d)......  No substantive
                                                    change.
1910.303(e)...................  1910.303(e)......  No substantive
                                                    change. (Individual
                                                    requirements are
                                                    placed in separate
                                                    paragraphs).
1910.303(f)...................  1910.303(f)(1),    No substantive
                                 (f)(2), and        change. (Individual
                                 (f)(3).            requirements are
                                                    placed in separate
                                                    paragraphs).
                                1910.303(f)(4)...  Adds a requirement
                                                    for disconnecting
                                                    means required by
                                                    Subpart S to be
                                                    capable of accepting
                                                    a lock. This
                                                    provision is added
                                                    to make the Subpart
                                                    S requirements on
                                                    disconnecting means
                                                    consistent with Sec.

                                                    1910.147(c)(2)(iii),
                                                    which requires
                                                    energy isolating
                                                    devices (a generic
                                                    term, which includes
                                                    electrical
                                                    disconnecting means)
                                                    to be designed to
                                                    accept a lockout
                                                    device.
                                1910.303(f)(5)...  **Adds marking
                                                    requirements for
                                                    series combination
                                                    ratings of circuit
                                                    breakers or fuses.
1910.303(g)(1), introductory    1910.303(g)(1),    No substantive
 text.                           introductory       change.
                                 text.
1910.303(g)(1)(i).............  1910.303(g)(1)(i)  **The final rule
                                 Table S-1, Note    revises the language
                                 3.                 to clarify how wide
                                                    and high the clear
                                                    space must be. (See
                                                    detailed explanation
                                                    later in the
                                                    preamble).
1910.303(g)(1)(ii)............  1910.303(g)(1)(ii  No substantive
                                 ).                 change.
1910.303(g)(1)(iii)...........  1910.303(g)(1)(ii  No substantive
                                 i).                change.
                                1910.303(g)(1)(iv  **Adds a requirement
                                 ).                 for a second
                                                    entrance on
                                                    equipment rated 1200
                                                    amperes under
                                                    certain conditions.
1910.303(g)(1)(iv)............  1910.303(g)(1)(i)  **Reduces the minimum
                                 (B).               width of the clear
                                                    space to 762 mm.
1910.303(g)(1)(v).............  1910.303(g)(1)(v)  **Adds a prohibition
                                                    against controlling
                                                    illumination for
                                                    working spaces by
                                                    automatic means
                                                    only.
1910.303(g)(1)(vi)............  1910.303(g)(1)(vi  **Increased the
                                 ).                 minimum height of
                                                    the working space
                                                    from 1.91m to 1.98m
                                                    for new
                                                    installations.
                                1910.303(g)(1)(vi  ** Adds requirements
                                 i).                for switchboards,
                                                    panelboards, and
                                                    distribution boards
                                                    installed for the
                                                    control of light and
                                                    power circuits, and
                                                    motor control
                                                    centers to be
                                                    installed in
                                                    dedicated space and
                                                    to be protected
                                                    against damage.
1910.303(g)(2)................  1910.303(g)(2)...  No substantive
                                                    change.
1910.303(h)(1)................  1910.303(h)(1)...  No substantive
                                                    change.
1910.303(h)(2), introductory    1910.303(h)(2)(i)  **The minimum height
 text.                           and (h)(2)(ii).    of fences
                                                    restricting access
                                                    to electrical
                                                    installations over
                                                    600 V is reduced
                                                    from 2.44 m to 2.13
                                                    m.
1910.303(h)(2)(i) and           1910.303(h)(2)(ii  **1. The final rule
 (h)(2)(ii).                     i), (h)(2)(iv),    organizes these
                                 (h)(2)(v), and     requirements based
                                 (h)(5)(iii).       on whether the
                                                    installations are
                                                    indoors or outdoors.
                                                    (The existing
                                                    standard organizes
                                                    them based on
                                                    whether or not the
                                                    installations are
                                                    accessible to
                                                    unqualified
                                                    employees).
                                                   2. Adds requirements
                                                    intended to prevent
                                                    tampering by the
                                                    general public.
                                                   3. Removes
                                                    requirement to lock
                                                    underground box
                                                    covers weighing more
                                                    than 45.4 kg.
1910.303(h)(3), introductory    1910.303(h)(3)...  No substantive
 text.                                              change.
1910.303(h)(3)(i).............  1910.303(h)(5)(i)  **The distances in
                                 Table S-2, Note    Table S-2 for the
                                 3.                 depth of working
                                                    space in front of
                                                    electric equipment
                                                    are increased for
                                                    new installations to
                                                    match the distances
                                                    in NFPA 70E-2000.
1910.303(h)(3)(ii)............  1910.303(h)(5)(iv  No substantive
                                 ).                 change.
1910.303(h)(3)(iii)...........  1910.303(h)(5)(v)  **The distances in
                                                    Table S-3 for the
                                                    elevations of
                                                    unguarded live parts
                                                    are increased for
                                                    new installations to
                                                    match the distances
                                                    in NFPA 70E-2000.
1910.303(h)(4)(i).............  1910.303(h)(4)(i)  **The existing
                                                    standard requires a
                                                    second entrance to
                                                    give access to the
                                                    working space about
                                                    switchboards and
                                                    control panels over
                                                    600 V if the
                                                    equipment exceeds
                                                    1.22 m in width if
                                                    it is practical to
                                                    install a second
                                                    entrance. The final
                                                    rule requires an
                                                    entrance on each end
                                                    of switchboards and
                                                    panelboards
                                                    exceeding 1.83 m
                                                    unless the working
                                                    space permits a
                                                    continuous and
                                                    unobstructed way of
                                                    travel or the
                                                    working space is
                                                    doubled. In
                                                    addition, the final
                                                    rule requires the
                                                    lone entrance
                                                    permitted under
                                                    either of these
                                                    exceptions to be at
                                                    least the distance
                                                    specified in Table S-
                                                    2 from exposed live
                                                    parts.
1910.303(h)(4)(ii)............  1910.303(h)(4)(ii  No substantive
                                 ).                 change.
                                1910.303(h)(5)(ii  **Adds requirements
                                 ).                 for equipment
                                                    operating at 600 V
                                                    or less installed in
                                                    rooms or enclosures
                                                    containing exposed
                                                    live parts or
                                                    exposed wiring
                                                    operating at more
                                                    than 600 V.
                                1910.303(h)(5)(vi  **Adds requirements
                                 ).                 limiting the
                                                    installation of
                                                    pipes or ducts that
                                                    are foreign to
                                                    electrical
                                                    installation
                                                    operating at more
                                                    than 600 V.
Sec.   1910.304 Wiring design   Sec.   1910.304
 and protection.                 Wiring design
                                 and protection.
1910.304(a)(1)................  1910.304(a)(1)...  No substantive
                                                    change. (Individual
                                                    requirements are
                                                    placed in separate
                                                    paragraphs).
1910.304(a)(2)................  1910.304(a)(2)...  No substantive
                                                    change.
1910.304(a)(3)................  1910.304(a)(3)...  No substantive
                                                    change.
                                1910.304(b)(1)...  **Adds requirements
                                                    for the
                                                    identification of
                                                    multiwire branch
                                                    circuits.
                                1910.304(b)(2)(i)  **Adds requirements
                                                    that receptacles
                                                    installed on 15- and
                                                    20-ampere circuits
                                                    be of the grounding
                                                    type and that
                                                    grounding-type
                                                    receptacles be
                                                    installed in
                                                    circuits within
                                                    their rating.
                                1910.304(b)(2)(ii  **Adds a requirement
                                 ).                 for grounding
                                                    contacts on
                                                    receptacles to be
                                                    effectively
                                                    grounded.
                                1910.304(b)(2)(ii  **Adds requirements
                                 i).                on the methods used
                                                    to ground
                                                    receptacles and cord
                                                    connectors.
                                1910.304(b)(2)(iv  **Adds requirements
                                 ).                 on the replacement
                                                    of receptacles.
                                1910.304(b)(2)(v)  **Adds a requirement
                                                    that receptacles
                                                    installed on branch
                                                    circuits having
                                                    different voltages,
                                                    frequencies, or
                                                    types of current be
                                                    noninterchangeable.
                                1910.304(b)(3)...  **Adds requirements
                                                    for ground fault
                                                    circuit interrupter
                                                    protection. (See the
                                                    discussion of these
                                                    requirements later
                                                    in this section of
                                                    the preamble).
1910.304(b)(2)................  1910.304(b)(4),    No significant
                                 introductory       change.
                                 text.
                                1910.304(b)(4)(i)  **Adds requirements
                                                    for ratings of
                                                    lampholders.
                                1910.304(b)(4)(ii  **Adds requirements
                                 ).                 for ratings of
                                                    receptacles.
                                1910.304(b)(5)...  **Adds requirements
                                                    for receptacles to
                                                    be installed
                                                    wherever cords with
                                                    attachment plugs are
                                                    used.
1910.304(c), introductory text  1910.304(c),       No significant
                                 introductory       change. (The
                                 text.              requirements in
                                                    existing paragraph
                                                    (c)(5) are placed in
                                                    a separate paragraph
                                                    (d)).
1910.304(c)(1)................  1910.304(c)(1)...  **Adds a requirement
                                                    for the separation
                                                    of conductors on
                                                    poles.
1910.304(c)(2)................  1910.304(c)(2)...  Increases the minimum
                                                    clearances for new
                                                    installations of
                                                    open conductors and
                                                    service drops to
                                                    match those in NFPA
                                                    70E-2000.
1910.304(c)(3)................  1910.304(c)(3)(i)  No substantive
                                                    change. (The final
                                                    rule clarifies that
                                                    paragraph (c)(2)
                                                    applies to
                                                    platforms,
                                                    projections, or
                                                    surfaces from which
                                                    runs of open
                                                    conductors can be
                                                    reached).
                                1910.304(c)(3)(ii  **Adds restrictions
                                 ).                 for installing
                                                    overhead service
                                                    conductors near
                                                    building openings
                                                    through which
                                                    materials may be
                                                    moved.
1910.304(c)(4)................  1910.304(c)(4)...  **Adds an exception
                                                    to the minimum
                                                    clearance
                                                    requirement for
                                                    conductors attached
                                                    to the side of a
                                                    building. (The final
                                                    rule also clarifies
                                                    that paragraph
                                                    (c)(2) applies to
                                                    roof surfaces that
                                                    are subject to
                                                    pedestrian or
                                                    vehicular traffic).
1910.304(c)(5)................  1910.304(d)......  No substantive
                                                    change.
1910.304(d)(1)(i).............  1910.304(e)(1)(i)  No substantive
                                                    change.
1910.304(d)(1)(ii)............  1910.304(e)(1)(ii  No substantive
                                 ).                 change.
                                1910.304(e)(1)(ii  **Adds a requirement
                                 i).                for service
                                                    disconnecting means
                                                    to be suitable for
                                                    the prevailing
                                                    conditions.
1910.304(d)(2)................  1910.304(e)(2)...  No substantive
                                                    change.
1910.304(e)(1), introductory    1910.304(f)(1),    No substantive
 text.                           introductory       change.
                                 text.
1910.304(e)(1)(i).............  1910.304(f)(1)(i)  No substantive
                                                    change.

[[Page 7149]]


1910.304(e)(1)(ii)............  1910.304(f)(1)(ii  No substantive
                                 ).                 change.
1910.304(e)(1)(iii)...........  1910.304(f)(1)(ii  **The types of
                                 i).                circuits that are
                                                    allowed to have a
                                                    single switch
                                                    disconnect for
                                                    multiple fuses are
                                                    now specified in the
                                                    standard.
1910.304(e)(1)(iv)............  1910.304(f)(1)(iv  No substantive
                                 ).                 change.
1910.304(e)(1)(v).............  1910.304(f)(1)(v)  **Adds a requirement
                                                    to clarify that
                                                    handles of circuit
                                                    breakers and similar
                                                    moving parts also
                                                    need to be guarded
                                                    so that they do not
                                                    injure employees.
1910.304(e)(1)(vi)(A).........  1910.304(f)(1)(vi  No substantive
                                 ).                 change.
1910.304(e)(1)(vi)(B).........  1910.304(f)(1)(vi  No substantive
                                 i).                change.
1910.304(e)(1)(vi)(C).........  1910.304(f)(1)(vi  **Adds circuit
                                 ii).               breakers used on 277-
                                                    volt fluorescent
                                                    lighting circuits to
                                                    the types of
                                                    breakers required to
                                                    be marked "SWD."
                                1910.304(f)(1)(ix  **Adds a requirement
                                 ).                 to clarify ratings
                                                    of circuit breakers.
1910.304(e)(2)................  1910.304(f)(2)...  **Adds specific
                                                    requirements on how
                                                    to protect feeders
                                                    and branch circuits
                                                    energized at more
                                                    than 600 volts.
1910.304(f), introductory text  1910.304(g),       No substantive
                                 introductory       change.
                                 text.
1910.304(f)(1), introductory    1910.304(g)(1),    No substantive
 text.                           introductory       change.
                                 text.
1910.304(f)(1)(i).............  1910.304(g)(1)(i)  No substantive
                                                    change.
1910.304(f)(1)(ii)............  1910.304(g)(1)(ii  No substantive
                                 ).                 change.
1910.304(f)(1)(iii)...........  1910.304(g)(1)(ii  No substantive
                                 i).                change.
1910.304(f)(1)(iv)............  1910.304(g)(1)(iv  No substantive
                                 ).                 change. (The
                                                    specific voltage
                                                    ratings in existing
                                                    paragraphs
                                                    (g)(1)(iv)(B) and
                                                    (g)(1)(iv)(C) are
                                                    being removed.
                                                    However, this is not
                                                    a substantive change
                                                    as those are the
                                                    voltages used in the
                                                    described systems).
1910.304(f)(1)(v).............  1910.304(g)(1)(v)  **Adds an exception
                                                    to the requirement
                                                    to ground systems
                                                    for high-impedance
                                                    grounded systems of
                                                    480 V to 1000 V
                                                    under certain
                                                    conditions.
1910.304(f)(2)................  1910.304(g)(2)...  **No substantive
                                                    change. (The
                                                    standard adds
                                                    descriptions of
                                                    which conductor is
                                                    to be grounded for
                                                    the different
                                                    systems).
                                1910.304(g)(3)...  **Changes
                                                    requirements for
                                                    grounding portable
                                                    and vehicle mounted
                                                    generators so that
                                                    the requirements are
                                                    equivalent to those
                                                    in OSHA's
                                                    Construction
                                                    Standards (Sec.
                                                    1926.404(f)(3)). The
                                                    sentence in the
                                                    construction
                                                    standard reading:
                                                    "No other
                                                    [nonneutral]
                                                    conductor need be
                                                    bonded to the
                                                    generator frame"
                                                    has been dropped
                                                    from the general
                                                    industry version.
                                                    This sentence is not
                                                    regulatory in
                                                    nature, and its
                                                    omission has no
                                                    effect on the
                                                    requirement.
1910.304(f)(3)................  1910.304(g)(4)...  **No longer allows
                                                    employers to use a
                                                    cold water pipe as a
                                                    source of ground for
                                                    installations made
                                                    or modified after
                                                    the effective date.
1910.304(f)(4)................  1910.304(g)(5)...  **Adds a requirement
                                                    that the path to
                                                    ground be effective.
1910.304(f)(5)(i).............  1910.304(g)(6)(i)  No substantive
                                                    change.
1910.304(f)(5)(ii)............  1910.304(g)(6)(ii  No substantive
                                 ).                 change.
1910.304(f)(5)(iii)...........  1910.304(g)(6)(ii  No substantive
                                 i).                change.
1910.304(f)(5)(iv)............  1910.304(g)(6)(iv  **The exceptions for
                                 ) and (g)(6)(v).   grounding fixed
                                                    equipment operating
                                                    at more than 150 V
                                                    are extended to all
                                                    fixed electric
                                                    equipment regardless
                                                    of voltage. Also,
                                                    the final rule
                                                    includes a new
                                                    exception for double-
                                                    insulated equipment.
1910.304(f)(5)(v).............  1910.304(g)(6)(vi  **Adds the following
                                 ) and              equipment to the
                                 (g)(6)(vii).       list of cord- and
                                                    plug-connected
                                                    equipment required
                                                    to be grounded:
                                                    stationary and fixed
                                                    motor-operated tools
                                                    and light industrial
                                                    motor-operated
                                                    tools.
1910.304(f)(5)(vi)............  1910.304(g)(7)...  **Adds frames and
                                                    tracks of
                                                    electrically
                                                    operated hoists to
                                                    the list of
                                                    nonelectrical
                                                    equipment required
                                                    to be grounded.
1910.304(f)(6)................  1910.304(g)(8)...  No substantive
                                                    change.
1910.304(f)(7)(i).............  1910.304(g)(9),    No substantive
                                 introductory       change.
                                 text.
1910.304(f)(7)(ii)............  1910.304(g)(9)(i)  No substantive
                                                    change.
1910.304(f)(7)(iii)...........  1910.304(g)(9)(ii  No substantive
                                 ).                 change.
Sec.   1910.305 Wiring          Sec.   1910.305
 methods, components, and        Wiring methods,
 equipment for general use.      components, and
                                 equipment for
                                 general use.
1910.305(a), introductory text  1910.305(a),       No substantive
                                 introductory       change.
                                 text.
1910.305(a)(1)(i).............  1910.305(a)(1)(i)  **Adds a requirement
                                                    that equipment be
                                                    bonded so as to
                                                    provide adequate
                                                    fault-current-
                                                    carrying capability.
                                                    Also, clarifies that
                                                    nonconductive
                                                    coatings need to be
                                                    removed unless the
                                                    fittings make this
                                                    unnecessary.
                                1910.305(a)(1)(ii  **Adds an exception
                                 ).                 to the bonding
                                                    requirement for the
                                                    reduction of
                                                    electrical noise.
1910.305(a)(1)(ii)............  1910.305(a)(1)(ii  No substantive
                                 i).                change.

[[Page 7150]]


1910.305(a)(2), introductory    1910.305(a)(2),    No substantive
 text.                           introductory       change. Removes the
                                 text.              provision allowing
                                                    temporary wiring to
                                                    be of a class less
                                                    than permanent
                                                    wiring per the 2002
                                                    NEC. The change has
                                                    no substantive
                                                    effect because: (1)
                                                    The term "a class
                                                    less than" is not
                                                    defined, and (2)
                                                    temporary wiring is
                                                    required to meet the
                                                    same requirements
                                                    regardless of the
                                                    deleted language.
                                                    (Both the final rule
                                                    and the existing
                                                    standard contain the
                                                    following
                                                    requirement:
                                                    "Except as
                                                    specifically
                                                    modified in this
                                                    paragraph, all other
                                                    requirements of this
                                                    subpart for
                                                    permanent wiring
                                                    shall apply to
                                                    temporary wiring
                                                    installations.").
1910.305(a)(2)(i),              1910.305(a)(2)(i)  No substantive
 introductory text.              , introductory     change.
                                 text.
1910.305(a)(2)(i)(A)..........  1910.305(a)(2)(i)  Removes demolition
                                 (A).               from the list of
                                                    activities for which
                                                    temporary wiring is
                                                    permitted.
                                                    Demolition is a form
                                                    of construction
                                                    work, which is not
                                                    covered by the
                                                    Subpart S
                                                    installation
                                                    requirements.
1910.305(a)(2)(i)(B)..........  1910.305(a)(2)(i)  **Adds emergencies to
                                 (C).               the list of
                                                    activities for which
                                                    temporary wiring is
                                                    permitted.
1910.305(a)(2)(i)(C)..........  1910.305(a)(2)(i)  No substantive
                                 (B).               change.
                                1910.305(a)(2)(ii  **Clarifies that
                                 ).                 temporary wiring
                                                    must be removed when
                                                    the project or
                                                    purpose for which it
                                                    was used has been
                                                    completed.
1910.305(a)(2)(ii)............  1910.305(a)(2)(ii  **Adds "construction-
                                 i).                like activities" to
                                                    the list of
                                                    permitted uses for
                                                    temporary electrical
                                                    installations over
                                                    600 volts.
1910.305(a)(2)(iii)(A)........  1910.305(a)(2)(iv  **Feeders may now
                                 ).                 only be run as
                                                    single insulated
                                                    conductors when
                                                    accessible to
                                                    qualified employees
                                                    only and used for
                                                    experiments,
                                                    development work, or
                                                    emergencies.
                                                    (Individual
                                                    requirements are
                                                    placed in separate
                                                    paragraphs).
1910.305(a)(2)(iii)(B)........  1910.305(a)(2)(v)  No substantive
                                                    change. (Individual
                                                    requirements are
                                                    placed in separate
                                                    paragraphs).
1910.305(a)(2)(iii)(C)........  1910.305(a)(2)(vi  No substantive
                                 ).                 change.
1910.305(a)(2)(iii)(D)........  1910.305(a)(2)(vi  No substantive
                                 i).                change.
1910.305(a)(2)(iii)(E)........  1910.305(a)(2)(vi  **Adds a requirement
                                 ii).               that disconnecting
                                                    means for a
                                                    multiwire circuit
                                                    simultaneously
                                                    disconnect all
                                                    ungrounded
                                                    conductors of the
                                                    circuit.
1910.305(a)(2)(iii)(F)........  1910.305(a)(2)(ix  **This provision no
                                 ).                 longer allows
                                                    installing fixtures
                                                    or lampholders more
                                                    than 2.1 meters
                                                    above the working
                                                    surface as a means
                                                    of guarding. Also,
                                                    the final rule adds
                                                    a requirement for
                                                    grounding metal-case
                                                    sockets.
1910.305(a)(2)(iii)(G)........  1910.305(a)(2)(x)  No substantive
                                                    change.
                                1910.305(a)(2)(xi  **Adds requirements
                                 ).                 for cable assemblies
                                                    and flexible cords
                                                    and cables to be
                                                    adequately
                                                    supported.
1910.305(a)(3)(i)(a)..........  1910.305(a)(3)(i)  No substantive
                                                    change. (Some
                                                    raceway and cable
                                                    types that were
                                                    included in generic
                                                    terms have been
                                                    explicitly added to
                                                    the list of wiring
                                                    methods acceptable
                                                    in cable trays).
1910.305(a)(3)(i)(b)..........  1910.305(a)(3)(ii  **Adds several types
                                 ).                 of cables and single
                                                    insulated conductors
                                                    to the list of types
                                                    permitted in
                                                    industrial
                                                    establishments.
                                1910.305(a)(3)(ii  **Adds a requirement
                                 i).                limiting the use of
                                                    metallic cable trays
                                                    as an equipment
                                                    grounding conductor.
1910.305(a)(3)(i)(c)..........  1910.305(a)(3)(iv  No substantive
                                 ).                 change.
1910.305(a)(3)(ii)............  1910.305(a)(3)(v)  No substantive
                                                    change.
1910.305(a)(4)(i).............  1910.305(a)(4)(i)  No substantive
                                                    change.
1910.305(a)(4)(ii)............  1910.305(a)(4)(ii  **Adds specific
                                 ).                 support requirements
                                                    and limits the
                                                    application of these
                                                    requirements to
                                                    conductors smaller
                                                    than No. 8.
1910.305(a)(4)(iii)...........  1910.305(a)(4)(ii  No substantive
                                 i).                change.
1910.305(a)(4)(iv)............  1910.305(a)(4)(iv  No substantive
                                 ).                 change.
1910.305(a)(4)(v).............  1910.305(a)(4)(v)  No substantive
                                                    change.
1910.305(b)(1)................  1910.305(b)(1)(i)  No substantive
                                 and (b)(1)(ii).    change. (Individual
                                                    requirements are
                                                    placed in separate
                                                    paragraphs).
                                1910.305(b)(1)(ii  **Adds requirements
                                 i).                for supporting
                                                    cables entering
                                                    cabinets, cutout
                                                    boxes, and meter
                                                    sockets.
1910.305(b)(2)................  1910.305(b)(2)(i)  No substantive
                                                    change.
                                1910.305(b)(2)(ii  **Adds a requirement
                                 ).                 for any exposed edge
                                                    of a combustible
                                                    ceiling finish at a
                                                    fixture canopy or
                                                    pan to be covered
                                                    with noncombustible
                                                    material.
1910.305(b)(3)................  1910.305(b)(3)...  No substantive
                                                    change. (Individual
                                                    requirements are
                                                    placed in separate
                                                    paragraphs).
1910.305(c)(1)................  1910.305(c)(1),    No substantive
                                 (c)(2), and        change. (Individual
                                 (c)(3)(i).         requirements are
                                                    placed in separate
                                                    paragraphs).
                                1910.305(c)(3)(ii  **Adds a requirement
                                 ).                 for load terminals
                                                    on switches to be
                                                    deenergized when the
                                                    switches are open
                                                    except under limited
                                                    circumstances.
                                1910.305(c)(4)...  **Adds a specific
                                                    requirement for
                                                    flush-mounted
                                                    switches to have
                                                    faceplates that
                                                    completely cover the
                                                    opening and that
                                                    seat against the
                                                    finished surface.
1910.305(c)(2)................  1910.305(c)(5)...  **Adds a requirement
                                                    to ground faceplates
                                                    for snap switches.
1910.305(d)...................  1910.305(d)......  No substantive
                                                    change. (Individual
                                                    requirements are
                                                    placed in separate
                                                    paragraphs).
1910.305(e)(1)................  1910.305(e)(1)...  **Adds a requirement
                                                    for metallic
                                                    cabinets, cutout
                                                    boxes, fittings,
                                                    boxes, and
                                                    panelboard
                                                    enclosures installed
                                                    in damp or wet
                                                    locations to have an
                                                    air space between
                                                    the enclosure and
                                                    the mounting
                                                    surface.
1910.305(e)(2)................  1910.305)(e)(2)..  No substantive
                                                    change.
1910.305(f)...................  1910.305(f)......  No substantive
                                                    change. (Individual
                                                    requirements are
                                                    placed in separate
                                                    paragraphs).
1910.305(g)(1)(i).............  1910.305(g)(1)(i)  **Adds the following
                                 and (g)(1)(ii).    to the types of
                                                    connections
                                                    permitted for
                                                    flexible cords and
                                                    cables: Portable and
                                                    mobile signs and
                                                    connection of moving
                                                    parts. The final
                                                    rule also clarifies
                                                    that flexible cords
                                                    and cables may be
                                                    used for temporary
                                                    wiring as permitted
                                                    in final Sec.
                                                    1910.305(a)(2).
1910.305(g)(1)(ii)............  1910.305(g)(1)(ii  No substantive
                                 i).                change.
1910.305(g)(1)(iii)...........  1910.305(g)(1)(iv  No substantive
                                 ).                 change. (Clarifies
                                                    that flexible cords
                                                    and cables may not
                                                    be installed inside
                                                    raceways).
1910.305(g)(1)(iv)............  1910.305(g)(1)(v)  **Permits additional
                                                    cord types to be
                                                    used in show windows
                                                    and show cases.
1910.305(g)(2)(i).............  1910.305(g)(2)(i)  **Adds new types of
                                                    cords to the list of
                                                    those that must be
                                                    marked with their
                                                    type designation.
1910.305(g)(2)(ii)............  1910.305(g)(2)(ii  **Changes the minimum
                                 ).                 size of hard service
                                                    and junior hard
                                                    service cords that
                                                    may be spliced from
                                                    No. 12 to 14.
1910.305(g)(2)(iii)...........  1910.305(g)(2)(ii  No substantive
                                 i).                change.
1910.305(h)...................  1910.305(h),       **Permits the minimum
                                 introductory       size of the
                                 text, (h)(1),      insulated ground-
                                 (h)(2), (h)(3),    check conductor of
                                 (h)(6), (h)(7),    Type G-GC cables to
                                 and (h)(8).        be No. 10 rather
                                                    than No. 8.
                                                    (Individual
                                                    requirements are
                                                    placed in separate
                                                    paragraphs).
                                1910.305(h)(4)...  **Adds a requirement
                                                    for shields to be
                                                    grounded.
                                1910.305(h)(5)...  **Adds minimum
                                                    bending radii
                                                    requirements for
                                                    portable cables.
1910.305(i)(1)................  1910.305(i)(1)...  No substantive
                                                    change.
1910.305(i)(2)................  1910.305(i)(2)...  No substantive
                                                    change.
1910.305(i)(3)................  1910.305(i)(3)...  **Also permits
                                                    fixture wire to be
                                                    used in fire alarm
                                                    circuits.
1910.305(j)(1)(i).............  1910.305(j)(1)(i)  No substantive
                                                    change.
1910.305(j)(1)(ii)............  1910.305(j)(1)(ii  No substantive
                                 ).                 change. (Clarifies
                                                    that metal-shell
                                                    paper-lined
                                                    lampholders may not
                                                    be used for
                                                    handlamps).
1910.305(j)(1)(iii)...........  1910.305(j)(1)(ii  **Adds a requirement
                                 i).                that the grounded
                                                    circuit conductor,
                                                    where present, be
                                                    connected to the
                                                    screw shell.
1910.305(j)(1)(iv)............  1910.305(j)(1)(iv  No substantive
                                 ).                 change.
                                1910.305(j)(2)(i)  **Adds requirements
                                                    to ensure that
                                                    attachment plugs and
                                                    connectors have no
                                                    exposed live parts.
1910.305(j)(2)(i).............  1910.305(j)(2)(ii  No substantive
                                 ).                 change.
                                1910.305(j)(2)(ii  **Clarifies that
                                 i).                nongrounding-type
                                                    receptacles may not
                                                    be used with
                                                    grounding-type
                                                    attachment plugs.
1910.305(j)(2)(ii)............  1910.305(j)(2)(iv  No substantive
                                 ).                 change.
                                1910.305(j)(2)(v)  **Adds requirements
                                 , (j)(2)(vi),      for receptacles
                                 and (j)(2)(vii).   outdoors to be
                                                    installed in
                                                    weatherproof
                                                    enclosures
                                                    appropriate for the
                                                    use of the
                                                    receptacle and for
                                                    the location.
1910.305(j)(3)(i).............  1910.305(j)(3)(i)  No substantive
                                                    change.
1910.305(j)(3)(ii)............  1910.305(j)(3)(ii  **Adds a requirement
                                 ).                 to group and
                                                    identify
                                                    disconnecting means
                                                    for appliances
                                                    supplied by more
                                                    than one source.
1910.305(j)(3)(iii)...........  1910.305(j)(3)(ii  **Adds requirements
                                 i).                for marking
                                                    frequency and
                                                    required external
                                                    overload protection
                                                    for appliances.
                                1910.305(j)(3)(iv  **Clarifies that
                                 ).                 markings must be
                                                    visible or easily
                                                    accessible after
                                                    installation.
1910.305(j)(4), introductory    1910.305(j)(4),    No substantive
 text.                           introductory       change.
                                 text.
1910.305(j)(4)(i).............  1910.305(j)(4)(i)  No substantive
                                                    change.
1910.305(j)(4)(ii)(A).........  1910.305(j)(4)(ii  No substantive
                                 ).                 change.
1910.305(j)(4)(ii)(B).........  1910.305(j)(4)(ii  No substantive
                                 i).                change.
1910.305(j)(4)(ii)(C).........  .................  Removed. All
                                                    disconnecting means
                                                    must be capable of
                                                    being locked in the
                                                    open position by
                                                    Sec.  Sec.
                                                    1910.302(c) and
                                                    1910.303(f)(4).
1910.305(j)(4)(ii)(D).........  1910.305(j)(4)(iv  No substantive
                                 ).                 change.
1910.305(j)(4)(ii)(E).........  1910.305(j)(4)(v)  No substantive
                                                    change.
1910.305(j)(4)(ii)(F).........  1910.305(j)(4)(vi  No substantive
                                 ).                 change.
1910.305(j)(4)(iii)...........  1910.305(j)(4)(vi  No substantive
                                 i).                change.
1910.305(j)(4)(iv)(A).........  .................  Removed. Covered by
                                                    Sec.
                                                    1910.303(g)(2),
                                                    (h)(2), and
                                                    (h)(4)(iii).
1910.305(j)(4)(iv)(B).........  1910.305(j)(4)(vi  No substantive
                                 ii).               change.
1910.305(j)(5)(i).............  1910.305(j)(5)(i)  No substantive
                                                    change.
1910.305(j)(5)(ii)............  1910.305(j)(5)(ii  No substantive
                                 ).                 change.
1910.305(j)(5)(iii)...........  1910.305(j)(5)(ii  No substantive
                                 i).                change.
1910.305(j)(5)(iv)............  1910.305(j)(5)(iv  No substantive
                                 ).                 change. (Oil-
                                                    insulated
                                                    transformers
                                                    installed indoors
                                                    are presumed to
                                                    present a hazard to
                                                    employees since a
                                                    transformer failure
                                                    will lead to a fire
                                                    within the building
                                                    unless the
                                                    transformer is
                                                    installed in a
                                                    vault).
1910.305(j)(5)(v).............  1910.305(j)(5)(v)  No substantive
                                                    change.
1910.305(j)(5)(vi)............  1910.305(j)(5)(vi  No substantive
                                 ).                 change.
1910.305(j)(5)(vii)...........  1910.305(j)(5)(vi  No substantive
                                 i).                change.
1910.305(j)(5)(viii)..........  1910.305(j)(5)(vi  No substantive
                                 ii).               change.
1910.305(j)(6)(i).............  1910.305(j)(6)(i)  No substantive
                                                    change.
1910.305(j)(6)(ii),             1910.305(j)(6)(ii  No substantive
 introductory text.              ), introductory    change.
                                 text.
                                1910.305(j)(6)(ii  **Adds requirements
                                 )(A) and           to provide
                                 (j)(6)(ii)(B).     disconnecting means
                                                    of adequate capacity
                                                    for capacitors
                                                    operating at more
                                                    than 600 V.
1910.305(j)(6)(ii)(A).........  1910.305(j)(6)(ii  No substantive
                                 )(C).              change.
1910.305(j)(6)(ii)(B).........  1910.305(j)(6)(ii  No substantive
                                 )(D).              change.
1910.305(j)(7)................  1910.305(j)(7)...  No substantive
                                                    change.
Sec.   1910.306 Specific        Sec.   1910.306
 purpose equipment and           Specific purpose
 installations.                  equipment and
                                 installations.
1910.306(a)(1)................  1910.306(a)(1)(i)  **Reorganized and
                                 , (a)(2)(i), and   clarified the
                                 (a)(2)(ii).        requirements for
                                                    disconnecting means
                                                    for signs. The final
                                                    rule does not apply
                                                    these requirements
                                                    to exit signs.
                                1910.306(a)(1)(ii  **Adds a requirement
                                 ).                 for the disconnects
                                                    for signs located
                                                    within fountains to
                                                    be at least 1.52 m
                                                    from the fountain
                                                    wall.
1910.306(a)(2)................  1910.306(a)(2)(ii  No substantive
                                 i).                change.
1910.306(b), introductory text  1910.306(b),       No substantive
                                 introductory       change.
                                 text.
1910.306(b)(1)(i).............  1910.306(b)(1)...  **Adds specific
                                                    requirements for the
                                                    type and location of
                                                    disconnecting means
                                                    for runway
                                                    conductors.
1910.306(b)(1)(ii)............  1910.306(b)(2)...  No substantive
                                                    change. (The final
                                                    rule reorganizes
                                                    these requirements).
1910.306(b)(2)................  1910.306(b)(3)...  No substantive
                                                    change.
1910.306(b)(3)................  1910.306(b)(4)...  No substantive
                                                    change.
1910.306(c)...................  1910.306(c),       **This paragraph now
                                 introductory       covers wheelchair
                                 text.              lifts, and stairway
                                                    chair lifts.
1910.306(c)(1)................  1910.306(c)(1)...  No substantive
                                                    change.
1910.306(c)(2)................  1910.306(c)(8)...  No substantive
                                                    change.
1910.306(c)(3)................  1910.306(c)(2)...  No substantive
                                                    change.
                                1910.306(c)(3)...  **Adds requirements
                                                    for the type of
                                                    disconnecting means.
                                1910.306(c)(4)...  **Adds requirements
                                                    for the operation of
                                                    disconnecting means.
                                1910.306(c)(5)...  **Adds requirements
                                                    for the location of
                                                    disconnecting means.
                                1910.306(c)(6)...  **Adds requirements
                                                    for the
                                                    identification of
                                                    disconnecting means.
                                1910.306(c)(7)...  **Adds requirements
                                                    for disconnecting
                                                    means for single car
                                                    and multicar
                                                    installations
                                                    supplied by more
                                                    than one source.
                                1910.306(c)(9)...  **Adds requirements
                                                    for warning signs
                                                    for interconnected
                                                    multicar
                                                    controllers.
                                1910.306(c)(10)..  **Adds exceptions
                                                    related to the
                                                    location of motor
                                                    controllers.
1910.306(d)(1)................  1910.306(d)(1)...  **Adds requirements
                                                    for the type and
                                                    rating of the
                                                    disconnecting means.
1910.306(d)(2)................  1910.306(d)(2)...  Clarifies that a
                                                    supply circuit
                                                    switch may be used
                                                    as a disconnecting
                                                    means if the circuit
                                                    supplies only one
                                                    welder.
1910.306(e)...................  1910.306(e)......  **Adds a requirement
                                                    to group the
                                                    disconnecting means
                                                    for the HVAC systems
                                                    serving information
                                                    technology rooms
                                                    with the
                                                    disconnecting means
                                                    for the information
                                                    technology
                                                    equipment. The final
                                                    rule exempts
                                                    integrated
                                                    electrical systems
                                                    covered by Sec.
                                                    1910.308(g). (The
                                                    existing standard
                                                    refers to this
                                                    equipment as data
                                                    processing
                                                    equipment).
1910.306(f), introductory text  1910.306(f),       **Adds coverage of X-
                                 introductory       rays for dental or
                                 text.              medical use.
1910.306(f)(1)(i).............  1910.306(f)(1)(i)  No substantive
                                                    change.
1910.306(f)(1)(ii)............  1910.306(f)(1)(ii  No substantive
                                 ).                 change.
1910.306(f)(2)(i).............  1910.306(f)(2)(i)  No substantive
                                                    change.
1910.306(f)(2)(ii)............  1910.306(f)(2)(ii  No substantive
                                 ).                 change.
1910.306(g)(1)................  1910.306(g),       No substantive
                                 introductory       change.
                                 text.
1910.306(g)(2)(i).............  1910.306(g)(1)(i)  No substantive
                                                    change.
1910.306(g)(2)(ii)............  1910.306(g)(1)(ii  No substantive
                                 ).                 change.
1910.306(g)(2)(iii)...........  1910.306(g)(1)(ii  **Adds a requirement
                                 i).                for the installation
                                                    of doors or
                                                    detachable panels to
                                                    provide access to
                                                    internal parts. Adds
                                                    a requirement that
                                                    detachable panels
                                                    not be readily
                                                    removable.
1910.306(g)(2)(iv)............  1910.306(g)(1)(iv  No substantive
                                 ).                 change.
1910.306(g)(2)(v).............  1910.306(g)(1)(v)  No substantive
                                                    change. (Individual
                                                    requirements are
                                                    placed in separate
                                                    paragraphs).
1910.306(g)(2)(vi)............  1910.306(g)(1)(vi  **Adds a requirement
                                 ).                 to ensure adequate
                                                    rating of
                                                    disconnecting means.
                                                    The final rule also
                                                    clarifies when the
                                                    supply circuit
                                                    disconnecting means
                                                    may be used as the
                                                    disconnecting means
                                                    for induction and
                                                    dielectric heating
                                                    equipment.
1910.306(g)(3)................  1910.306(g)(2)...  No substantive
                                                    change. (Individual
                                                    requirements are
                                                    placed in separate
                                                    paragraphs).
1910.306(h)(1)................  1910.306(h),       No substantive
                                 introductory       change.
                                 text.
1910.306(h)(2)................  1910.399.........  No substantive
                                                    change.
1910.306(h)(3)................  1910.306(h)(1)...  No substantive
                                                    change.
1910.306(h)(4)(i) and           1910.306(h)(2)...  No substantive
 (h)(4)(ii).                                        change. (The two
                                                    provisions are
                                                    combined into one
                                                    paragraph).
1910.306(h)(5)(i).............  1910.306(h)(3)(i)  No substantive
                                                    change.
1910.306(h)(5)(ii)............  1910.306(h)(3)(ii  No substantive
                                 ).                 change.
1910.306(h)(6)(i).............  1910.306(h)(4)(i)  **Adds requirements
                                                    limiting primary and
                                                    secondary voltage on
                                                    isolating
                                                    transformers
                                                    supplying
                                                    receptacles for
                                                    ungrounded cord- and
                                                    plug-connected
                                                    equipment. Also,
                                                    adds requirement for
                                                    overcurrent
                                                    protection for
                                                    circuits supplied by
                                                    these transformers.
1910.306(h)(6)(ii)............  1910.306(h)(4)(ii  No substantive
                                 ).                 change.
1910.306(h)(6)(iii)...........  1910.306(h)(4)(ii  No substantive
                                 i).                change. (Individual
                                                    requirements are
                                                    placed in separate
                                                    paragraphs).
1910.306(h)(7)(i) and           1910.306(h)(5)(i)  No substantive
 (h)(7)(ii).                                        change.
1910.306(h)(7)(iii)...........  1910.306(h)(5)(ii  No substantive
                                 ).                 change.
1910.306(h)(7)(iv)............  1910.306(h)(5)(ii  No substantive
                                 i).                change.
1910.306(h)(8)................  1910.306(h)(6)...  No substantive
                                                    change.
1910.306(h)(9)................  1910.306(h)(7)...  No substantive
                                                    change.
1910.306(i)(1)................  1910.306(i)(1)...  No substantive
                                                    change.
1910.306(i)(2)................  1910.306(i)(2)...  **Allows the
                                                    disconnecting means
                                                    for a center pivot
                                                    irrigation machine
                                                    to be located not
                                                    more than 15.2 m (50
                                                    ft) from the machine
                                                    if the disconnecting
                                                    means is visible
                                                    from the machine.
                                                    (Individual
                                                    requirements are
                                                    placed in separate
                                                    paragraphs).
1910.306(j)(1)................  1910.306(j),       **Clarifies that
                                 introductory       hydro-massage
                                 text.              bathtubs are covered
                                                    by this paragraph.
1910.306(j)(2)(i).............  1910.306(j)(1)(i)  No substantive
                                                    change.
                                1910.306(j)(1)(ii  **Extends the
                                 ).                 boundary within
                                                    which receptacles
                                                    require ground-fault
                                                    circuit interrupter
                                                    protection from 4.57
                                                    m (15 ft) to 6.08 m
                                                    (20 ft) for new
                                                    installations.
                                1910.306(j)(1)(ii  **Adds requirements
                                 i).                for the installation
                                                    of at least one
                                                    receptacle near
                                                    permanently
                                                    installed pools at
                                                    dwelling units.
1910.306(j)(2)(ii)(A).........  1910.306(j)(2)(i)  **Clarifies that
                                                    ceiling suspended
                                                    (paddle) fans are
                                                    covered by this
                                                    requirement.
1910.306(j)(2)(ii)(B).........  1910.306(j)(2)(ii  No substantive
                                 ).                 change.
1910.306(j)(3)................  1910.306(j)(3)...  No substantive
                                                    change.
1910.306(j)(4)(i).............  1910.306(j)(4)(i)  No substantive
                                                    change.
1910.306(j)(4)(ii)............  1910.306(j)(4)(ii  No substantive
                                 ).                 change.
                                1910.306(j)(4)(ii  **Adds a requirement
                                 i).                to guard lighting
                                                    fixtures facing
                                                    upward.
1910.306(j)(5)................  1910.306(j)(5)...  No substantive
                                                    change.
                                1910.306(k)......  **Adds requirements
                                                    for carnivals,
                                                    circuses, fairs, and
                                                    similar events.
Sec.   1910.307 Hazardous       Sec.   1910.307
 (classified) locations.         Hazardous
                                 (classified)
                                 locations.
1910.307(a)...................  1910.307(a)......  **Adds the Zone
                                                    classification
                                                    system for Class I
                                                    locations. (See
                                                    detailed discussion
                                                    later in this
                                                    section of the
                                                    preamble).
                                1910.307(b)......  **Adds documentation
                                                    requirements for
                                                    hazardous locations
                                                    classified using
                                                    either the division
                                                    or zone
                                                    classification
                                                    system. (See
                                                    detailed discussion
                                                    later in this
                                                    section of the
                                                    preamble).
1910.307(b), introductory text  1910.307(c),       No substantive
                                 introductory       change.
                                 text.
1910.307(b)(1)................  1910.307(c)(1)...  No substantive
                                                    change.
1910.307(b)(2)(i).............  1910.307(c)(2)(i)  No substantive
                                                    change.
1910.307(b)(2)(ii),             1910.307(c)(2)(ii  No substantive
 introductory text.              ), introductory    change.
                                 text.
1910.307(b)(2)(ii)(A).........  1910.307(c)(2)(ii  No substantive
                                 )(A).              change.
1910.307(b)(2)(ii)(B).........  1910.307(c)(2)(ii  **Also permits
                                 )(B).              fixtures approved
                                                    for Class II,
                                                    Division 2 locations
                                                    to omit the group
                                                    marking.
1910.307(b)(2)(ii)(C).........  1910.307(c)(2)(ii  No substantive
                                 )(C).              change.
1910.307(b)(2)(ii)(D).........  1910.307(c)(2)(ii  No substantive
                                 )(D).              change.
                                1910.307(c)(2)(ii  **Adds a requirement
                                 )(E).              that electric
                                                    equipment suitable
                                                    for an ambient
                                                    temperature
                                                    exceeding 40 [deg]C
                                                    (104 [deg]F) be
                                                    marked with the
                                                    maximum ambient
                                                    temperature.
1910.307(b)(3)................  1910.307(c)(3)...  No substantive
                                                    change.
1910.307(b)(3), Note..........  1910.307(c)(3),    The last sentence of
                                 Note.              the note is removed
                                                    to make it clear
                                                    that the OSHA
                                                    standard does not
                                                    incorporate the
                                                    National Electrical
                                                    Code by reference.
                                                    The NEC continues to
                                                    be a guideline that
                                                    employers may
                                                    reference in
                                                    determining the type
                                                    and design of
                                                    equipment and
                                                    installations that
                                                    will meet the OSHA
                                                    standard.
1910.307(c)...................  1910.307(d)......  No substantive
                                                    change.
1910.307(d)...................  1910.307(e)......  No substantive
                                                    change.

[[Page 7154]]


                                1910.307(f)......  **The final rule adds
                                                    a list of specific
                                                    protective
                                                    techniques for
                                                    electrical
                                                    installations in
                                                    hazardous locations
                                                    classified under the
                                                    division
                                                    classification
                                                    system.
                                1910.307(g)......  **Adds the zone
                                                    classification
                                                    system as an
                                                    alternative method
                                                    of installing
                                                    electric equipment
                                                    in hazardous
                                                    locations. This
                                                    paragraph sets the
                                                    protective
                                                    techniques and other
                                                    requirements
                                                    necessary for safe
                                                    installation of
                                                    electric equipment
                                                    in hazardous
                                                    locations classified
                                                    under the zone
                                                    classification
                                                    system. (See
                                                    detailed discussion
                                                    later in this
                                                    section of the
                                                    preamble).
Sec.   1910.308 Special         Sec.   1910.308
 systems.                        Special systems.
1910.308(a), introductory text  1910.308(a),       No substantive
                                 introductory       change.
                                 text.
1910.308(a)(1)(i).............  1910.308(a)(1)(i)  **Adds the following
                                 and (a)(3)(ii).    wiring methods to
                                                    those acceptable for
                                                    installations
                                                    operating at more
                                                    than 600 V:
                                                    Electrical metallic
                                                    tubing, rigid
                                                    nonmetallic conduit,
                                                    busways, and cable
                                                    bus. The proposal
                                                    also removes the
                                                    specific requirement
                                                    to support cables
                                                    having a bare lead
                                                    sheath or a braided
                                                    outer covering in a
                                                    manner to prevent
                                                    damage to the braid
                                                    or sheath. This
                                                    hazard is covered by
                                                    Sec.
                                                    1910.303(b)(1) and
                                                    (b)(8)(i) and new
                                                    Sec.
                                                    1910.308(a)(4).
1910.308(a)(1)(ii)............  1910.308(a)(1)(ii  No substantive
                                 ).                 change.
                                1910.308(a)(2)     ** Adds requirements
                                 and (a)(3)(i).     to ensure that high-
                                                    voltage cables can
                                                    adequately handle
                                                    the voltage stresses
                                                    placed upon them and
                                                    to ensure that any
                                                    coverings are flame
                                                    retardant.
                                1910.308(a)(4)...  **Adds requirements
                                                    for the protection
                                                    of high-voltage
                                                    cables against
                                                    moisture and
                                                    physical damage
                                                    where the cable
                                                    conductors emerge
                                                    from a metal sheath.
1910.308(a)(2)(i).............  1910.308(a)(5)(i)  No substantive
                                                    change.
                                1910.308(a)(5)(ii  **Adds requirements
                                 ).                 for fuses to protect
                                                    each ungrounded
                                                    conductor, for
                                                    adequate ratings of
                                                    fuses installed in
                                                    parallel, and for
                                                    the protection of
                                                    employees from power
                                                    fuses of the vented
                                                    type.
1910.308(a)(2)(ii)............  1910.308(a)(5)(ii  **Clarifies that
                                 i).                distribution cutouts
                                                    are not suitable for
                                                    installation in
                                                    buildings or
                                                    transformer vaults.
                                1910.308(a)(5)(iv  **Adds requirements
                                 ).                 for fused cutouts to
                                                    either be capable of
                                                    interrupting load
                                                    current or be
                                                    supplemented by a
                                                    means of
                                                    interrupting load
                                                    current. In
                                                    addition, a warning
                                                    sign would be
                                                    required for fused
                                                    cutouts that cannot
                                                    interrupt load
                                                    current.
                                1910.308(a)(5)(v)  **Adds a requirement
                                                    for guarding
                                                    nonshielded cables
                                                    and energized parts
                                                    of oil-filled
                                                    cutouts.
                                1910.308(a)(5)(vi  **Adds requirements
                                 ).                 to ensure that load
                                                    interrupting
                                                    switches will be
                                                    protected against
                                                    interrupting fault
                                                    current and to
                                                    provide for warning
                                                    signs for backfed
                                                    switches.
1910.308(a)(2)(iii)...........  1910.308(a)(5)(vi  No substantive
                                 i).                change.
1910.308(a)(3)................  1910.308(a)(6)...  No substantive
                                                    change.
1910.308(a)(4)(i).............  1910.308(a)(7),    No substantive
                                 introductory       change.
                                 text.
1910.308(a)(4)(ii)............  1910.308(a)(7)(i)  No substantive
                                 and (a)(7)(iii).   change. (Individual
                                                    requirements are
                                                    placed in separate
                                                    paragraphs).
                                1910.308(a)(7)(ii  **Clarifies that
                                 ).                 multiconductor
                                                    portable cable may
                                                    supply mobile
                                                    equipment.
1910.308(a)(4)(iii)...........  1910.308(a)(7)(iv  No substantive
                                 ) and (a)(7)(v).   change. (Individual
                                                    requirements are
                                                    placed in separate
                                                    paragraphs).
                                1910.308(a)(7)(vi  **Limits the
                                 ).                 conditions under
                                                    which switch or
                                                    contactor enclosures
                                                    may be used as
                                                    junction boxes or
                                                    raceways.
1910.308(a)(4)(iv)............  1910.308(a)(7)(vi  No substantive
                                 i).                change.
1910.308(a)(4)(v).............  1910.308(a)(7)(vi  No substantive
                                 ii).               change.
1910.308(b)(1)................  1910.308(b),       No substantive
                                 introductory       change.
                                 text.
1910.308(b)(2)................  1910.308(b)(1)...  No substantive
                                                    change.
1910.308(b)(3)................  1910.308(b)(2)...  **Clarifies that
                                                    emergency
                                                    illumination
                                                    includes all
                                                    required means of
                                                    egress lighting,
                                                    illuminated exit
                                                    signs, and all other
                                                    lights necessary to
                                                    provide required
                                                    illumination.
                                1910.308(b)(3)...  **Adds requirements
                                                    to provide signs
                                                    indicating the
                                                    presence and
                                                    location of on-site
                                                    emergency power
                                                    sources under
                                                    certain conditions.
1910.308(c)(1), introductory    1910.308(c)(1),    No substantive
 text.                           introductory       change.
                                 text.
1910.308(c)(1)(i), (c)(1)(ii),  1910.308(c)(1)(i)  **Clarifies the power
 and (c)(1)(iii).                , (c)(1)(ii),      limitations of Class
                                 and (c)(1)(iii).   1, 2, and 3 remote
                                                    control, signaling,
                                                    and power-limited
                                                    circuits based on
                                                    equipment listing.
1910.308(c)(2)................  1910.308(c)(2)...  No substantive
                                                    change.
                                1910.308(c)(3)...  **Adds requirements
                                                    for the separation
                                                    of cables and
                                                    conductors of Class
                                                    2 and Class 3
                                                    circuits from cables
                                                    and conductors of
                                                    other types of
                                                    circuits.
1910.308(d)(1)................  1910.308(d)(1)...  No substantive
                                                    change.
1910.308(d)(2), introductory    1910.308(d)(2),    No substantive
 text.                           introductory       change.
                                 text.
1910.308(d)(2)(i).............  1910.308(d)(2)(i)  No substantive
                                                    change.
1910.308(d)(2)(ii)............  1910.308(d)(2)(ii  **Adds a requirement
                                 ).                 for power-limited
                                                    fire alarm circuit
                                                    power sources to be
                                                    listed and marked as
                                                    such.
1910.308(d)(3)................  1910.308(d)(3)(i)  No substantive
                                                    change.
1910.308(d)(4)................  1910.308(d)(3)(ii  **Clarifies the
                                 ), (d)(3)(iii),    requirements for
                                 and (d)(3)(iv).    installing power-
                                                    limited fire-
                                                    protective signaling
                                                    circuits with other
                                                    types of circuits.
                                                    (Individual
                                                    requirements are
                                                    placed in separate
                                                    paragraphs).
1910.308(d)(5)................  1910.308(d)(4)...  No substantive
                                                    change.
1910.308(e)(1)................  1910.308(e),       No substantive
                                 introductory       change.
                                 text.
1910.308(e)(2)................  1910.308(e)(1)...  **Clarifies the
                                                    requirement for
                                                    listed primary
                                                    protectors to make
                                                    it clear that
                                                    circuits confined
                                                    within a block do
                                                    not need protectors.
1910.308(e)(3)(i).............  1910.308(e)(2)(i)  No substantive
                                 and (e)(2)(ii).    change.
1910.308(e)(3)(ii)............  1910.308(e)(2)(ii  No substantive
                                 i).                change.
1910.308(e)(3)(iii)...........  1910.308(e)(2)(iv  No substantive
                                 ).                 change.
1910.308(e)(4)................  1910.308(e)(3)...  No substantive
                                                    change.
1910.308(e)(5)................  1910.308(e)(4)...  No substantive
                                                    change.
                                1910.308(f)......  **Adds requirements
                                                    to separate
                                                    conductors of solar
                                                    photovoltaic systems
                                                    from conductors of
                                                    other systems and to
                                                    provide a
                                                    disconnecting means
                                                    for solar
                                                    photovoltaic
                                                    systems.
                                1910.308(g)......  **Adds an exception
                                                    to the provisions on
                                                    the location of
                                                    overcurrent
                                                    protective devices
                                                    for integrated
                                                    electrical systems.
------------------------------------------------------------------------
Note to table:
**These new and revised provisions are included in the 2000 and 2004
  editions of NFPA 70E standard. The NFPA 70E Committee believes that
  these provisions, which were taken from the 1999 and 2002 NEC,
  respectively, are essential to employee safety. OSHA agrees with the
  consensus of NFPA's expert opinion that these requirements are
  reasonably necessary to protect employees and has included them in the
  final rule. On occasion, OSHA has rewritten the provision to lend
  greater clarity to its requirements. However, these editorial changes
  to the language of NFPA 70E do not represent substantive differences.
  NFPA's handling of these provisions and the rationale underpinning
  them is a matter of public record for the NEC and NFPA 70E and is part
  of the record for this rulemaking (Exs. 2-9 through 2-18). OSHA agrees
  with the rationale in this record as it pertains to the new and
  revised provisions the Agency is adopting.

 F. General Requirements (Sec.  1910.303)

    Paragraph (b) of proposed Sec.  1910.303 contained a general 
requirement for electric equipment to be free of recognized hazards 
likely to cause death or serious physical harm to employees. This 
provision also contained criteria for judging the safety of electric 
equipment. One of the criteria was suitability for installation and use 
in accordance with Subpart S, and a note following paragraph (b)(1)(i) 
indicated that listing or labeling by a nationally recognized testing 
laboratory could be evidence of suitability.
    The National Multihousing Council recommended adding a second note 
to this paragraph to indicate that nothing in this provision was to be 
taken as a directive that limits a local jurisdiction's authority to 
amend the adopted electrical code (Ex. 4-20).
    Local electrical inspection authorities have jurisdiction over 
public safety as well as employee safety and this jurisdiction is not 
preempted by OSHA standards. OSHA does not believe that a note to the 
standard is necessary to clarify this authority. Indeed, the 
recommended note might serve to confuse employers and employees, 
leading them to believe that OSHA might enforce those local 
requirements. Therefore, Sec.  1910.303(b)(1)(i) in the final standard 
does not include such a note.
    In paragraph (g) of proposed Sec.  1910.303, OSHA would have 
required the employer to maintain sufficient access and working space 
about electric equipment to permit ready and safe operation and 
maintenance of equipment. This paragraph would have required the access 
and working space to meet certain minimum dimensions. One commenter 
expressed concern regarding the physical space about electric equipment 
on ships (Ex. 3-7). This commenter argued that, in shipbuilding and 
repair, the limited space on a ship is a design concern for shore-based 
equipment. He stated that some shore-based electric equipment is placed 
in locations that ensure safe access to disconnect switches in the 
event of an emergency or routine connection of other equipment and that 
the working space in these locations can be limited. However, he stated 
that his company deenergizes and removes shore-based equipment before 
servicing or maintenance.
    OSHA believes that this commenter's installation complies with 
final Sec.  1910.303(g). The introductory text to paragraph (g)(1) 
contains the general requirement that sufficient access and working 
space shall be provided and maintained about all electric equipment to 
permit ready and safe operation and maintenance of such equipment. 
These provisions ensure that employees maintaining electric equipment 
while it is energized have enough room to work without danger of 
contacting energized parts and grounded parts or two circuit parts 
energized at different potentials simultaneously. The specific 
dimensions required by paragraph (g)(1)(i) apply only to equipment 
likely to require examination, adjustment, servicing, or maintenance 
while it is energized. As long as the employer implements, 
communicates, and enforces a policy to ensure that the equipment is 
deenergized before employees engage in any of these tasks that might 
expose them to contact with energized parts, paragraph (g)(1)(i) does 
not apply, and the equipment need not provide the specific amount of 
working space required by that provision. In the commenter's case, the 
employer not only deenergizes the equipment but removes it from the 
space in question altogether, thus providing an additional measure of 
safety. On the other hand, if the equipment were not deenergized, then 
employees would not be able to work on the equipment safely.
    Table S-3 and Sec.  1910.303(h)(5)(v) in the proposed rule would 
have required a minimum elevation of 2.8 m (9.0 ft) for unguarded live 
parts operating at 601 to 7500 V and located above working space. A 
note following proposed Table S-3 permitted the minimum elevation to be 
2.6 m (8.5 ft) for installations built before the effective date of the 
final standard. However, Table S-3 in the existing standard provides 
for a minimum elevation of 2.4 m (8.0 ft) for installations built before 
April 16, 1981, if the voltage is in the range of 601 to 6600 V. OSHA 
unintentionally omitted this exception for older installations from the 
footnote to Table S-3 in the proposal. The Agency does not intend for 
installations made before April 16, 1981, to be modified to provide an 
additional 0.2 m (0.5 ft) of elevation. Therefore, the Agency is carrying 
forward the language from the existing standard allowing for the reduced 
minimum elevation for those older installations.

G. Branch Circuits--Identification of Multiwire Branch Circuits

    Identification requirements. Paragraph (b)(1) of final Sec.  
1910.304 adds requirements for identification of multiwire branch 
circuits. The rule requires that all ungrounded conductors of multiwire 
branch circuits in a building be identified, where accessible, by phase 
and system where more than one nominal voltage system exists. It goes 
on to add that the identification means shall be permanently posted at 
each branch circuit panelboard. For example, the identification means 
can be color coding, marking tape, or tagging.
    For instance, a building served by both 208Y/120-volt and 480Y/277-
volt multiwire branch circuits must use a wiring identification means. 
One method of meeting final Sec.  1910.304(b)(1) would be to use a 
color-coded scheme with brown, orange, and yellow insulation for the 
480-volt system's phase conductors and black, red, and blue insulation 
for the 208-volt system's phase conductors. A legend, which may include 
other information such as the panelboard identification, must be 
permanently affixed at each branch circuit panelboard to identify the 
respective phase and system color-coding scheme.
    One commenter requested clarification of the term "where 
accessible" used in Sec.  1910.304(b)(1) of the proposed rule (Ex. 4-
14). He questioned whether the identification means must be posted at 
each pull and junction box. He suggested allowing a color-coding scheme 
identified in the employer's written electrical safety program.
    OSHA believes that the typical means of complying with this 
provision, which was ultimately taken from 1999 NEC Section 210-
4(d),\13\ will be to use conductors with insulation of different colors 
for each system and post a legend identifying which colors are used 
with which systems at each panelboard. The color-coded conductors for 
each circuit are visible at each pull and junction box, which are 
locations where the conductors are accessible; thus, the employees can 
determine the voltage on a circuit and at utilization equipment or 
devices such as motors or receptacle outlets by referring to the legend 
at the panelboard supplying the circuit. Final Sec.  1910.304(b)(1) 
requires the legend to be posted at the panelboard for each branch 
circuit, not at the pull and junction boxes.
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    \13\ Section 210-4(d) of the 1999 NEC reads as follows:
    (d) Identification of Ungrounded Conductors. Where more than one 
nominal voltage system exists in a building, each ungrounded 
conductor of a multiwire branch circuit, where accessible, shall be 
identified by phase and system. This means of identification shall 
be permitted to be by separate color coding, marking tape, tagging, 
or other approved means and shall be permanently posted at each 
branch-circuit panelboard.
---------------------------------------------------------------------------

    The requirements proposed in Sec.  1910.304(b)(1) and (b)(3) for 
ungrounded conductors of systems of different voltages to be identified 
were very similar. Proposed paragraph (b)(1) would have required 
identification of multiwire branch circuits \14\ only, whereas 
paragraph (b)(3) would have required identification regardless of 
whether a circuit was a multiwire circuit. Paragraph (b)(1) was taken 
from NFPA 70E-2000 Section 2-2.1, and paragraph (b)(3) was taken from 
NFPA 70E-2000 Section 2-2.3 (Ex. 2-2). In addition, both NFPA sections 
are taken from 1999 NEC Section 210-4(d). Proposed paragraph (b)(3) 
inadvertently omitted language from the NFPA standard (Section 2-2.3) 
restricting its application to multiwire circuits. Although no one 
submitted comments on this problem, OSHA has decided to correct this 
error by not carrying proposed Sec.  1910.304(b)(3) into the final 
rule.
---------------------------------------------------------------------------

    \14\ A multiwire branch circuit is a branch circuit that 
consists of two or more ungrounded conductors that have a voltage 
between them and a grounded conductor that has equal voltage between 
it and each ungrounded conductor of the circuit and that is 
connected to the neutral or grounded conductor of the system.
---------------------------------------------------------------------------

H. Branch Circuits--Ground-Fault Circuit-Interrupters for Employees

    Introduction. Each year many employees suffer electric shocks while 
using portable electric tools and equipment. The nature of the injuries 
ranges from minor burns to electrocution. Electric shocks produced by 
alternating currents (ac) at power line frequency passing through the 
body of an average adult from hand to foot for 1 second can cause 
various effects, starting from a condition of being barely perceptible 
at 1 milliampere to loss of voluntary muscular control for currents 
from 9 to 25 milliamperes. The passage of still higher currents, from 
75 milliamperes to 4 amperes, can produce ventricular fibrillation of 
the heart; and, finally, immediate cardiac arrest at over 4 amperes. 
These injuries occur when employees contact electrically energized 
parts. Typically, the frame of a tool becomes accidentally energized 
because of an electrical fault (known as a ground fault) that provides 
a conductive path to the tool casing. For instance, with a grounded 
electric supply system, when the employee contacts the tool casing, the 
fault current takes a path through the employee to an electrically 
grounded object. The amount of current that flows through an employee 
depends, primarily, upon the resistance of the fault path within the 
tool, the resistance of the path through the employee's body, and the 
resistance of the paths, both line side and ground side, from the 
employee back to the electric power supply. Moisture in the atmosphere 
can contribute to the electrical fault by enhancing both the conductive 
path within the tool and the external ground path back to the electric 
power supply. Dry skin can have a resistance range of anywhere from 
about 500 to 500,000 ohms and wet skin can have a resistance range of 
about 200 to 20,000, depending on several factors, such as the physical 
characteristics and mass of the employee. More current will flow if the 
employee is perspiring or becomes wet because of environmental 
conditions. If the current is high enough, the employee will suffer a 
ground-fault electrocution.
    One method of protection against injuries from electric shock is 
the ground-fault circuit-interrupter (GFCI). This device continually 
monitors the current flow to and from electric equipment. If the 
current going out to the protected equipment differs by approximately 
0.005 amperes (5-milliamperes) from the current returning, then the 
GFCI will deenergize the equipment within as little as 25 milliseconds, 
quickly enough to prevent electrocution.
    GFCI requirements. Paragraph (b)(3) of final Sec.  1910.304 sets 
new requirements for ground-fault circuit-interrupter protection of 
receptacles and cord connectors used in general industry. Paragraph 
(b)(3)(i) requires ground-fault circuit protection for all 125-volt, 
single-phase, 15- and 20-ampere receptacles installed in bathrooms and 
on rooftops. As noted earlier, this provision only applies to 
installations made after the effective date of the final rule. Cord 
sets and cord- and plug-connected equipment in these locations can get 
wet and expose employees to severe ground-fault hazards. The NFPA 70E 
Technical Committee believes, and OSHA agrees, that using 125-volt, 
15- and 20-ampere cord- and plug-connected equipment in these locations 
exposes employees to great enough risk of ground-fault electrocution 
(as noted earlier) to warrant the protection afforded by GFCIs.\15\
---------------------------------------------------------------------------

    \15\ Part I 2-2.4.1 of NFPA 70E, 2000 edition, requires GFCI 
protection for all 120-volt, single-phase, 15- and 20-ampere 
receptacles installed in bathrooms and on rooftops for other than 
dwelling units.
---------------------------------------------------------------------------

    Paragraph (b)(3)(ii) of final Sec.  1910.304 requires GFCI 
protection for all receptacle outlets on temporary wiring installations 
that are used during maintenance, remodeling, or repair of buildings, 
structures, or equipment, or during similar construction-like 
activities.\16\ Such activities include cleanup, disaster remediation, 
and restoration of large electrical installations.
---------------------------------------------------------------------------

    \16\ See also the discussion of the term "construction-like 
activities" under the summary and explanation of final Sec.  
1910.305(a)(2), later in this section of the preamble. It should be 
noted that the discussion of the term "construction-like 
activities" is intended for application only to the use of this 
term in Subpart S.
---------------------------------------------------------------------------

    OSHA currently requires GFCI protection for 120-volt, single-phase, 
15- and 20-ampere temporary receptacle outlets used on construction 
sites (Sec.  1926.404(b)(1)). In the 28 years that this requirement has 
been in effect, the Agency estimates that between about 650 and 1,100 
lives have been saved because of it.\17\ Temporary wiring associated 
with construction-like activities in general industry exposes employees 
to the same ground-fault hazards as those associated with temporary 
receptacle outlets on construction sites. In Sec.  1910.304(b)(3)(ii), 
OSHA is extending the ground-fault protection requirement to temporary 
receptacles used in construction-like activities performed in general 
industry. At the same time, this final rule extends protection to 
temporary wiring receptacles of higher voltage and current ratings 
(such as 125-volt, single-phase, 30-ampere and 480-volt, three-phase 
receptacles). It better protects employees from ground-fault hazards 
than the construction rule because it covers other equipment that is 
just as subject to damage as 120-volt, single-phase, 15- and 20-ampere 
equipment and that is more prevalent today than when the construction 
rule was promulgated over 28 years ago.
---------------------------------------------------------------------------

    \17\ In the preamble to the final rule adopting a requirement 
for GFCIs on construction sites, OSHA estimated that there were 
between 30 and 45 deaths per year caused by 120-volt ground faults 
on construction sites, and the Agency determined that nearly all of 
those deaths could be prevented by the use of GFCI protection or an 
assured grounding program (41 FR 55701, December 21, 1976). OSHA 
fatality investigation data indicate that 46 deaths involving 120-
volt ground-faults in temporary wiring occurred over the years 1990 
to 1996 (the latest year for which data are complete). This is a 
death rate of only 6.6 per year. Thus, OSHA believes that the rule 
has saved between 23 and 39 lives per year or, over the 28 years the 
rule has been in effect, a total of between about 650 and 1,100 
lives.
---------------------------------------------------------------------------

    The Agency had proposed not to permit the NFPA 70E "Assured 
Grounding Program" as an alternative to GFCIs in this rule. NFPA 70E's 
Assured Grounding Program, differs in several important respects from 
the assured equipment grounding conductor program in OSHA's 
construction standards (Sec.  1926.404(b)(1)). For example, NFPA 70E 
permits the Assured Grounding Program as an alternative to GFCI 
protection for personnel (1) for 125-volt, single-phase, 15- and 20-
ampere receptacle outlets in industrial establishments only, with 
conditions of maintenance and supervision that ensure that only 
qualified personnel are involved, and (2) for receptacle outlets rated 
other than 125 volts, single-phase, 15, 20, or 30 amperes. The OSHA 
construction rule recognizes an assured equipment grounding conductor 
program as an alternative to GFCIs without restriction. Additionally, 
under its Assured Grounding Program, NFPA 70E requires electric 
equipment to be tested only when there is evidence of damage. This is 
in contrast to the assured equipment grounding conductor program 
required by OSHA's construction standard, which requires electric 
equipment to be tested after any incident that can reasonably be 
suspected to have caused damage.
    During the development of the proposal, OSHA had considered 
including NFPA 70E's Assured Grounding Program or the construction 
standard's assured equipment grounding conductor program requirements 
as alternatives to GFCIs, but rejected them. In the preamble to the 
proposal, OSHA gave the following reasons for rejecting NFPA's Assured 
Grounding Program: (1) The differences between the general industry and 
construction requirements would have been too confusing for employers 
who are subject to both standards, and (2) the NFPA alternative would 
offer less protection for employees than the assured equipment 
grounding conductor program in OSHA's construction standard. 
Additionally, OSHA reasoned in the proposal that requiring GFCIs alone, 
without even the construction standard's assured equipment grounding 
conductor program as an alternative, would provide better protection 
for employees. The construction standard's assured equipment grounding 
conductor program demands constant vigilance on the part of employees 
to provide them with the same level of protection as GFCIs. Under that 
program, employers must perform rigorous inspections and tests of cord 
sets and cord- and plug-connected equipment generally at 3-month 
intervals and employees must inspect them daily. In contrast, GFCIs 
constantly monitor the circuit for ground faults and open the circuit 
when ground-fault current becomes excessive without the need for either 
the employer or the employee to take action. Because three fourths of 
all electrical accidents are caused by poor work practices (55 FR 
31986), OSHA believes that GFCIs are a more reliable method of 
protecting employees.
    OSHA received several comments generally supportive of the proposed 
requirement for GFCIs for 125-volt, single-phase, 15- and 20-ampere 
receptacles installed in bathrooms or on rooftops and for all 125-volt, 
single-phase, 15-, 20-, and 30-ampere receptacle outlets that are not 
part of the permanent wiring of the building or structure and that are 
in use by personnel (Exs. 3-5, 3-6, 3-10, 4-9, 4-23, 4-24). For 
example, the American Society of Safety Engineers (ASSE) supported the 
new requirements for GFCI protection of receptacles and cord connectors 
and for temporary wiring installations, stating that this is an 
important aspect of the rule (Ex. 3-5). ASSE stated that this 
requirement will greatly contribute to the rule's effectiveness in 
saving lives and it is also consistent with OSHA's current requirements 
in 29 CFR Part 1926 for construction sites. Another commenter supported 
OSHA's statement in the proposal that GFCIs for temporary wiring 
installations have been required in the NEC for many years and that the 
requirement overall does not impose any hardships on employers (Ex. 5-
2). One of the commenters agreed that GFCIs provide continuous 
protection for employees (Ex. 4-9). A comment (Ex. 4-24) from the 
National Electrical Manufacturers Association (NEMA) stated that GFCIs 
provide better protection for employees and a safer workplace than the 
alternate assured equipment grounding conductor program included in 
OSHA's construction standard. NEMA added that GFCIs provide continuous 
protection whereas the assured equipment grounding conductor program 
requires monthly inspection. NEMA recommended that the assured
equipment grounding program not be added as an alternative to GFCIs in 
the general industry electrical installation standard.
    Other commenters opposed OSHA's proposal not to include the assured 
grounding program as an alternative to GFCIs (Exs. 3-3, 3-6, 3-10, 4-
11, 4-14, 4-19, 4-23). Some of them hinted that GFCI-type receptacles 
and circuit breakers at voltages above 125 volts, 15, 20, and 30 
amperes may require constant attention because of nuisance tripping 
(Exs. 3-6, 3-10, 4-11, 4-19, 4-23). They added that it is possible and 
likely that construction-type portable equipment used in industry will 
trip GFCIs during normal operation. For example, Mike Johnson of 
International Paper argued that portable welding units for the repair 
of major pieces of equipment such as industrial boilers and other 
massive pieces of equipment pose a real concern (Ex. 3-6). He noted 
that the cord sets on such portable equipment are typically heavier and 
less prone to damage than cords furnished with 125-volt equipment. He 
further noted his experience with tripping of GFCIs during the normal 
use of hermetic compressors, which are used for temporary cooling of 
personnel. Some of those objecting to the omission of the assured 
equipment grounding conductor program alternative argued that to avoid 
nuisance tripping on circuits of more than 125 volts, they would be 
forced to keep circuits very short beyond the location of the GFCI 
protection (Exs. 4-11, 4-19). Another commenter, Alcoa, supported the 
use of GFCI protection for all temporary 125-volt, single-phase wiring, 
including the use of extension cord sets, but did not support the use 
of GFCI protection on 480-volt, three-phase extension cord sets or 480-
volt temporary wiring (Ex. 4-14). Finally, some commenters argued that 
the lack of commercially available GFCIs at voltages higher than 125 
volts makes it impossible to comply with Sec.  1910.304(b)(4)(ii) as 
proposed (Exs. 4-11, 4-19, 4-23).
    These commenters gave three reasons why the Agency should permit an 
assured equipment grounding conductor program as an alternative to 
GFCIs, particularly at voltages higher than 125 volts: (1) Because, 
they asserted, the assured equipment grounding conductor program is 
equally effective; (2) because of tripping caused by (a) the inherently 
high leakage current for some electric equipment or (b) the capacitive 
leakage on long circuits of voltages over 125 volts; and (3) because 
GFCIs are not available for all branch-circuit voltage and current 
ratings.
    Nothing in the record has convinced the Agency that its preliminary 
conclusion that GFCIs are more effective protection than the assured 
equipment grounding conductor program is incorrect. In fact, the 2002 
NEC, which permits its assured equipment grounding conductor program as 
an alternative to GFCIs only in very limited circumstances,\18\ 
indicates that NFPA has reached the same conclusion. OSHA disagrees 
with the commenters' assertion that the assured equipment grounding 
conductor program provides protection equivalent to GFCIs. Thus, the 
Agency has determined based on the record that GFCIs are a more 
effective means of protecting employees than the assured equipment 
grounding conductor program.
---------------------------------------------------------------------------

    \18\ NEC Section 527.6 requires electric shock or electrocution 
protection for personnel using temporary wiring during activities 
such as construction, remodeling, maintenance, repair, demolition, 
and the like. GFCI protection or a written assured equipment 
grounding conductor program must be used to provide this protection. 
All 125-volt, single-phase 15-, 20-, and 30-ampere receptacle 
outlets must have GFCI protection except that in industrial 
establishments only, where only qualified personnel perform 
maintenance, the assured equipment grounding conductor program is 
permitted for specific situations. The limitations of the exception 
in industrial establishments only are for situations in which: (1) 
Qualified personnel are using equipment that is not compatible, by 
design, with GFCI protection or (2) a greater hazard exists if power 
was interrupted by GFCI protection.
    For receptacle outlets other than those rated 125 volts, single 
phase 15, 20, and 30 amperes, personnel protection must be provided 
by either GFCI protection or a written assured equipment grounding 
conductor program.
---------------------------------------------------------------------------

    The Agency cannot determine whether the commenters concerns about 
tripping caused by capacitive charging currents between the circuit 
conductors and the equipment grounding conductor at voltages over 125 
volts are valid. For multiphase circuits, capacitive currents should 
balance out across the phases. Even on single-phase circuits, employers 
should be able to control leakage and capacitive currents by limiting 
the length of the conductors between the GFCI and the utilization 
equipment.
    However, OSHA recognizes the limited availability of GFCIs for 
circuits operating at voltages above 125 volts to ground. Consequently, 
it would be very difficult, if not impossible, for employers to comply 
with a requirement for GFCI protection for all branch-circuit ratings. 
For this reason, OSHA has decided to permit an assured equipment 
grounding conductor program as an alternative to GFCIs when approved 
GFCIs are unavailable for the voltage and current rating of the circuit 
involved. However, the final rule does require employers to provide 
GFCI protection whenever these devices are available at the branch-
circuit rating involved. The Agency anticipates that approved 1-, 2-, 
and 3-pole GFCIs for branch-circuits with ratings above 125 volts and 
30 amperes will become available in the future. Employers will need to 
use those new devices for any temporary wiring installed after they do 
become available. OSHA will continue to monitor developments in this 
area and inform employers as appropriate of the availability of GFCIs.
    Certain equipment designs cause tripping of GFCIs. For example, 
some motors, due to design or application, have higher leakage current 
to ground than a GFCI will allow. In other cases, GFCI tripping can 
result in undesired consequences. For example, the NEC requires GFCI-
protected receptacles in garages at residences but allows for a non-
GFCI receptacle for large appliances such as a food freezer. If the 
GFCI trips, the food in the freezer will spoil. An NEC exception to 
GFCI protection for temporary installations recognizes the 
incompatibility of these types of equipment on a GFCI-protected circuit 
and allows the assured equipment grounding conductor program in place 
of GFCIs under certain circumstances. Another NEC exception allows the 
assured equipment grounding conductor program for temporary 
installations where a greater hazard exists if power is interrupted by 
a GFCI. For example, a motor for a ventilation fan used to exhaust 
toxins in the atmosphere may not be compatible with GFCI protection. 
Loss of the fan because of tripping by a GFCI can pose a risk to 
employee health and safety. However, OSHA believes that even this type 
of equipment should not be subject to the risks associated with 
temporary cord- and plug-connected wiring. The Agency believes that 
hard-wired methods, which avoid the use of a plug-receptacle 
combination, afford better protection of employees relying on such 
critical equipment. Because the GFCI requirement applies only to 
receptacle outlets, employers can avoid having to install GFCIs by 
wiring the equipment directly to the circuit conductors at an outlet or 
panelboard.
    Many of the commenters supporting the assured grounding alternative 
recommended that the Agency include an assured equipment grounding 
conductor program consistent with OSHA's existing requirements in 29 
CFR 1926.404(b)(1)(iii) as an alternative to using GFCIs for protection 
of personnel (Exs. 3-3, 3-5, 3-6). For example, ASSE recommended that 
OSHA work at harmonizing this program with the assured equipment
grounding conductor program permitted under OSHA's construction 
standards (Ex. 3-5). ASSE did concur that OSHA's testing program in the 
construction standard, which requires testing after any incident that 
can reasonably be suspected to have caused damage, is preferable to the 
approach taken in NFPA 70E.
    OSHA agrees with these commenters that any assured equipment 
grounding conductor program in the general industry standards must be 
consistent with the corresponding construction standard in Sec.  
1926.404(b)(1)(iii). The Agency maintains that the assured equipment 
grounding conductor program in the existing construction standards is 
more protective than NFPA's assured grounding program. OSHA's 
construction standard requires testing of all cord sets and receptacles 
whenever it can reasonably be suspected that an incident may have 
caused damage to the equipment, whereas the NFPA standard requires 
testing only if an incident produces evidence of damage. The purpose of 
the assured equipment grounding conductor program is designed to detect 
and correct damage to the equipment grounding conductor particularly 
when it is unseen. Demanding evidence of damage, as NFPA does, 
partially thwarts that purpose. Therefore, the Agency has brought the 
assured equipment grounding conductor program from Sec.  
1926.404(b)(1)(iii) into this revision of the general industry 
electrical installation standard. The final rule requires employers to 
use the assured equipment grounding conductor program whenever approved 
GFCIs are not available.
    Although the assured equipment grounding conductor program in the 
final rule is consistent with the one in the construction standard, the 
final rule, unlike the construction standard, does not always permit it 
to be used as an alternative to GFCIs. The determination that GFCIs are 
a preferable form of protection and not to permit the assured equipment 
grounding conductor in all circumstances is based on the public record 
of this rulemaking. The final rule applies only to general industry and 
not to construction. OSHA will not enforce this rule for construction 
work; however, employers are encouraged to use GFCIs in accordance with 
the general industry standard even when the construction standard 
applies.
    The assured equipment grounding conductor program in the 
construction standard relies on the definition of "competent person" 
in Sec.  1926.32(f).\19\ The assured equipment grounding conductor 
program in this final rule also requires one or more competent persons 
for implementation. Consequently, the Agency is bringing the definition 
of "competent person" from OSHA's construction standards into final 
Sec.  1910.399.
---------------------------------------------------------------------------

    \19\ Paragraph (f) of Sec.  1926.32 reads as follows:
    Competent person means one who is capable of identifying 
existing and predictable hazards in the surroundings or working 
conditions which are unsanitary, hazardous, or dangerous to 
employees, and who has authorization to take prompt corrective 
measures to eliminate them.
---------------------------------------------------------------------------

    OSHA received numerous comments concerning proposed Sec.  
1910.304(b)(4)(ii)(A). The pertinent part of this proposed provision 
read, "receptacles on a 2-wire, single-phase portable or vehicle-
mounted generator rated not more than 5 kW, where the circuit 
conductors of the generator are insulated from the generator frame and 
all other grounded surfaces, are permitted without ground-fault 
circuit-interrupter protection for personnel." This exemption from the 
GFCI requirement was taken from NFPA 70E-2000.
    Several commenters recommended removing this exemption (Exs. 4-13, 
4-15, 4-17, 4-18, 4-21). These commenters stated that this exemption 
has been removed from the most recent editions of the NEC and NFPA 70E. 
They argued that there was never any technical justification for this 
provision and, thus, its inclusion in the OSHA standard is unjustified.
    OSHA agrees with these comments and has decided to remove this 
exemption to better align the final rule with the consensus standards. 
The proposed exemption from the GFCI requirement for portable and 
vehicle-mounted generators was based on 1999 NEC Section 305-6(a), 
Exception 1. The exemption in the 1999 NEC and the exemption in 
proposed Sec.  1910.304(b)(4)(ii)(A) were the same as the exemption for 
portable and vehicle-mounted generators in OSHA's construction 
requirement for ground-fault circuit-interrupters (Sec.  
1926.404(b)(1)(ii)). In promulgating the construction standard, OSHA 
gave the following rationale for exempting these generators from the 
requirement for GFCI protection:

    On generators whose supply wires are not required to be 
grounded, and are in fact not grounded, the return path for a 
ground-fault current to flow is not completed and the hazard which a 
GFCI would protect against is not present. Consequently, the rule as 
promulgated in [Sec.  1926.404(b)(1)(ii)] does not require the use 
of GFCI's on portable or vehicle-mounted generators of 5kW capacity 
or less if its output is a two-wire, single-phase system and its 
circuit conductors are insulated from the generator frame and all 
other grounded surfaces. [41 FR 55702, December 21, 1976]

    The NEC used to require only neutral conductors to be bonded to the 
generator frame. (See, for example, 1981 NEC Section 250-6.) The NEC 
now requires single-phase, two-wire circuits to have one circuit 
conductor bonded to the generator frame. (See Sections 250-26 and 250-
34(c) of the 1999 NEC and Sections 250.26 and 250.34(C) of the 2002 
NEC.) Thus, the NEC no longer permits generators to be wired so as to 
meet the conditions in the proposed exemption. That is, because one of 
the circuit conductors must be bonded to the generator frame, the 
conductors cannot be "insulated from the generator frame" as required 
by the exemption.
    In addition, connecting one conductor on a single-phase, two-wire 
generator to the generator frame facilitates the operation of a GFCI 
when a ground fault occurs. Even though the generator frame is not 
required to be grounded, it frequently is, through direct contact with 
ground or through grounding-type equipment, which has its equipment 
grounding conductor connected to the generator frame. Bonding one of 
the circuit conductors to the generator frame provides a path outside 
the circuit conductors for ground-fault current to flow. Such current 
will be detected by a GFCI. If the circuit conductors are insulated 
from the generator frame, it is more likely that any ground fault 
current will return through the circuit conductors and go undetected by 
a GFCI.\20\
---------------------------------------------------------------------------

    \20\ For a ground fault to occur on an ungrounded circuit, two 
faults must be present. If both faults are on the load side of the 
GFCI, then any leakage current will go undetected.
---------------------------------------------------------------------------

    For these reasons, OSHA has determined that the exemption from the 
GFCI requirement for single-phase generators is not warranted and has 
revised final Sec.  1910.304(b)(3)(ii)(A) (proposed Sec.  
1910.304(b)(4)(ii)(A)) accordingly. In addition, the evidence in the 
record indicates that it is also necessary to revise the generator 
grounding requirements in final Sec.  1910.304(g)(2) and (g)(3)(iii) to 
match Sections 250.26 and 250.34(C) of the 2002 NEC, respectively. (See 
the summary and explanation of these provisions later in this section 
of the preamble.) Removing the exception from final Sec.  
1910.304(b)(3)(ii)(A) without revising the generator grounding 
provisions would result in a requirement for GFCIs when they would not 
work as intended to protect employees. Incorporating the NEC
provisions on generator grounding will work in concert with the GFCI 
provisions to ensure that employees are adequately protected from 
ground faults.
    OSHA proposed Note 2 to Sec.  1910.304(b)(4)(ii)(A) to read as 
follows:

    Cord sets and devices incorporating listed ground-fault circuit-
interrupter protection for personnel are acceptable forms of 
protection.

    Several commenters suggested that the note be reworded to recognize 
portable GFCI protection only when it is placed at the end closest to 
the source of power (Exs. 4-13, 4-15, 4-17, 4-18, 4-21). They argued 
that GFCI protection should be provided for the entire cord set and 
that the only way to do so is to put the GFCI at the source of 
power.\21\
---------------------------------------------------------------------------

    \21\ The National Electrical Code Handbook for the 2002 NEC, in 
its explanation of the NEC requirements for GFCI protection for 
temporary installations, identifies a GFCI device as being designed 
for insertion at the line, or source, end of a flexible cord set. 
The short style of cord set shown in the Handbook lends itself to 
in-series connection with single or multiple, series-connected, cord 
sets.
---------------------------------------------------------------------------

    OSHA agrees with these commenters and has revised the note to read:

    Cord sets and devices incorporating the required ground-fault 
circuit-interrupter that are connected to the receptacle closest to 
the source of power are acceptable forms of protection.

    This language, which was similar to that recommended by these 
commenters, will provide the most effective protection for employees 
using temporary wiring. Employers using portable GFCIs to comply with 
final Sec.  1910.304(b)(3)(ii)(A) must install them at the first 
receptacle on the circuit (the end closest to the source of power). 
This will protect employees from faults in all downstream cord sets and 
equipment.

I. Accessibility of Overcurrent Devices

    Proposed Sec.  1910.304(f)(1)(iv) addressed the location of 
overcurrent devices. The first sentence of this provision would have 
required overcurrent devices to be accessible "to each employee or 
authorized building management personnel."
    OSHA received a request to insert the word "qualified" before 
"employee" in that provision (Ex. 4-22). The commenter was concerned 
that the provision would require every employee at the workplace to 
have access to overcurrent devices.
    This proposed provision is identical to existing Sec.  
1910.304(e)(1)(iv) and is consistent with Sec.  240.24 of the 2002 NEC. 
The wording of this provision permits employers to restrict access to 
authorized building management personnel. Consequently, the proposed 
rule does not require access by every employee, and there is no need to 
revise the language of the rule.

J. Grounding

    Proposed Sec.  1910.304(g)(1) listed systems that would have been 
required to be grounded. Proposed paragraphs (g)(1)(iv) and (g)(1)(v) 
governed grounded and ungrounded ac systems of 50 to 1000 volts. These 
two paragraphs were substantively the same as paragraphs (f)(1)(iv) and 
(f)(1)(v) of existing Sec.  1910.304, except that in the existing rule 
ac circuits of 480 to 1000 volts are permitted to use a high-impedance 
grounded neutral in lieu of a neutral with a direct connection to the 
grounding electrode.
    In a joint comment, CHS Inc., and the National Cooperative Refinery 
Association (NCRA) expressed concern about these provisions (Ex. 4-25). 
These two companies requested that the Agency consider permitting the 
operation of three-phase ungrounded delta systems that have been 
utilized for many years by the refining industry and others for 
electrical systems. They argued that these systems became popular in 
the early 20th century because of the need to operate loads without 
interruption because of the operation of overcurrent protection devices 
on a short circuit. The comment referenced Soares Book on Grounding 
published by the International Association of Electrical Inspectors. 
Quoting this book, the commenter stated that the reason to operate a 
system in this manner is to "obtain an additional degree of service 
continuity. Since the system is ungrounded, the occurrence of the first 
ground fault (as distinguished from a short circuit) on the system will 
not cause an overcurrent protective device to open." CHS and NCRA 
further noted that these ungrounded systems are used with ground 
detection equipment and that trained electrical maintenance personnel 
investigate and repair problems without causing an abrupt outage.
    Electrical systems are grounded primarily to:
    (1) Limit overvoltages caused by lightning, line surges, or contact 
with higher voltage systems;
    (2) Stabilize voltage to earth during normal operation; and
    (3) Facilitate the operation of overcurrent devices protecting the 
circuit. (See 1999 NEC Section 250-2.) \22\
---------------------------------------------------------------------------

    \22\ Soares Book on Grounding, a recognized reference on 
grounding to which CHS and NCRA referred, offers a list of known 
disadvantages of operating ungrounded three-phase ac systems as 
follows:
    Disadvantages of operating systems ungrounded include but are 
not limited to the following:
    1. Power system overvoltages are not controlled. In some cases, 
these overvoltages are passed through transformers into the premises 
wiring system. Some common sources of overvoltages include: 
lightning, switching surges and contact with a high voltage system.
    2. Transient overvoltages are not controlled, which, over time, 
may result in insulation degradation and failure.
    3. System voltages above ground are not necessarily balanced or 
controlled.
    4. Destructive arcing burnouts can result if a second fault 
occurs before the first fault is cleared.
---------------------------------------------------------------------------

    An ac system that is connected for ungrounded operation is a system 
that is connected to ground via the capacitance of the insulating 
medium, be it air, rubber or thermoplastic insulation. The capacitance-
to-ground varies resulting in system operating problems. The line-to-
ground voltage is not constant. Such erratic voltage makes ungrounded 
systems difficult to troubleshoot.
    OSHA views these conditions as hazardous to employees working near 
the power system. A hazard of this type of installation is the 
possibility for the frame of a piece of equipment to become energized 
at some voltage above ground. A shock hazard exists if an employee 
simultaneously touches the equipment and a grounded object such as a 
handrail.
    In general, the NEC and the IAEI Soares Book on Grounding cite very 
similar if not the same recommendations for grounding of electrical 
systems, and the final rule parallels these requirements. In fact, 
contrary to the suggestions made by the commenters, the provisions in 
question are entirely consistent with the IAEI Soares Book on 
Grounding. Paragraph (g)(1)(iv) of final Sec.  1910.304 requires delta 
systems of 50 to 1000 volts \23\ to be grounded only if:
---------------------------------------------------------------------------

    \23\ Systems over 1000 volts are covered by final Sec.  
1910.304(g)(9), to which CHS and NRCA did not object.
---------------------------------------------------------------------------

    (1) They can be grounded so that the maximum voltage to ground on 
the ungrounded conductors does not exceed 150 volts (that is, a delta 
system with a phase-to-phase voltage of 150 volts or less),
    (2) The system is a three-phase, four-wire delta circuit in which 
the midpoint of one phase is used as a circuit conductor, or
    (3) A service conductor is uninsulated.
    OSHA believes that few delta systems meet any of these conditions, 
in which case the final rule does not require them to be grounded. Even 
if one of those conditions is met, the circuit may operate using a 
high-impedance grounded neutral system as permitted by final 
Sec.  1910.304(g)(1)(v)(E). Such systems provide higher system 
reliability in a manner similar to ungrounded systems in that a single 
ground fault triggers alarms on ground-detection equipment instead of 
causing the circuit protective devices to deenergize the circuit. 
However, these systems provide better protection against ground faults 
and overvoltages than do ungrounded systems.
    Finally, the provisions to which CHS and NCRA refer are not new 
requirements. They are in the existing OSHA electrical standard and 
have been enforced by the Agency since 1972.
    For all of these reasons, OSHA believes that grounded systems are a 
much more reliable method of protecting employees than ungrounded 
systems and has retained Sec.  1910.304(g)(1)(iv) and (g)(1)(v) as 
proposed.
    For the reasons presented under the summary and explanation of 
final Sec.  1910.304(b)(3)(ii)(A) (proposed Sec.  
1910.304(b)(4)(ii)(A)), earlier in this section of the preamble, OSHA 
is revising the grounding requirements in Subpart S for consistency 
with 2002 NEC Sections 250.26 and 250.34(C). This revision is in two 
parts: A new provision (final Sec.  1910.304(g)(2)) and a revised 
provision (final Sec.  1910.304(g)(3)(iii), proposed Sec.  
1910.304(g)(2)(iii)). Final Sec.  1910.304(g)(2), which had no 
counterpart in the proposal, adopts requirements from 2002 NEC Section 
250.26 specifying which conductor in an ac system must be grounded. 
This new provision complements final Sec.  1910.303(g)(1), which 
specifies which systems must be grounded. These two provisions ensure 
that the voltage to ground on ungrounded conductors is minimized. It 
should be noted that final Sec.  1910.304(g)(2) requires a system 
conductor to be grounded only when that system is required to be 
grounded by Sec.  1910.304(g)(1).
    Paragraph (g)(3)(iii) of final Sec.  1910.304 is revised to match 
2002 NEC Section 250.34(C). The revised provision requires that any 
system conductor required to be grounded by final Sec.  1910.304(g)(2) 
be bonded to the generator frame, which serves as the grounding 
electrode for the system. This requirement ensures that systems fed by 
portable and vehicle-mounted generators are wired consistently with 
service-supplied systems and provide a level of safety equal to that of 
service-supplied systems.
    Proposed Sec.  1910.304(g)(3)(iii) (final Sec.  
1910.304(g)(4)(iii)) stated, "On extensions of existing branch 
circuits that do not have an equipment grounding conductor, grounding-
type receptacles may be grounded to a grounded cold water pipe near the 
equipment."
    OSHA received several comments on the use of cold water pipes for 
equipment grounding connections (Exs. 4-4, 4-13, 4-15, 4-17, 4-18, 4-
21). For example, Mr. Brooke Stauffer of the National Electrical 
Contractors Association (NECA) recommended deleting this requirement 
from the standard, arguing that this method of grounding is not 
permitted in the 2002 NEC (Ex. 3-2). He noted that Section 250.52 of 
the NEC states that an interior metal water pipe more than 1.52 meters 
(5 feet) from the point of entrance of the water pipe into the building 
is no longer allowed to serve as part of the grounding electrode 
system. Other comments stated that using an isolated equipment 
grounding conductor such as a cold water pipe may increase the risk of 
reactance along the equipment grounding conductor when an ac fault is 
involved (Exs. 4-4, 4-13, 4-15, 4-17, 4-18, 4-21). For example, one 
commenter stated that using a water pipe to ground equipment violates 
2002 NEC Section 300.3(B), which requires all circuit conductors to be 
grouped together so magnetic fields are offset and reluctance is 
minimized (Exs. 4-13, 4-15). He further argued that plastic pipe makes 
water pipes an unreliable ground and that using water pipes to ground 
electric equipment can pose hazards to employees working on the piping 
system, as follows:

    Water pipes cannot be counted upon to serve the same function as 
an equipment grounding conductor, which is to prevent electrocution 
due to malfunctioning equipment on the branch circuit by allowing 
large amounts of current to flow and trip the overcurrent device. 
The use of water pipes as equipment grounding conductors is actually 
more likely to cause an electrocution in the event that a plumber, 
pipe-fitter or similar professional working on the water piping 
system would break a pipe connection involved in a fault, thereby 
exposing themselves to the full lethal circuit voltage and providing 
a path for current to flow. Unlike electrical workers working on 
branch circuits, there are no specific requirements for plumbers, 
pipe-fitters or similar professionals to deenergize and lock out 
electrical circuits in order to work on plumbing systems, nor should 
there be one.
    The advent of current technology and practice of using 
nonmetallic pipe in all or part of a plumbing system would cause 
metallic parts of equipment or sections of the water piping to 
become energized if a tool or equipment were to malfunction and 
expose anyone (plumber, pipe-fitter, general plant employee) to an 
electrocution hazard from simple contact with the piping system. 
[Ex. 4-13]

    OSHA agrees with these comments. It is important for the equipment 
grounding conductor to be reliable and of low impedance. Water pipes 
are neither. In addition, as noted by this commenter, employees working 
on water pipes used in this manner can be exposed to hazardous 
differences in electrical potential across an open pipe. On the other 
hand, OSHA has allowed grounded cold water pipes to be used for 
grounding branch circuit extensions since 1972. (See, for example, 
existing Sec.  1910.304(f)(3)(iii).\24\) Since there have been very few 
reported accidents, the Agency does not believe that the risk to 
employees, not to mention the substantial cost to employers, of 
rerunning these branch circuit extensions is worth the reduction in 
risk associated with the continued use of water pipes for grounding 
purposes. To redo a branch circuit extension, an employee would need to 
deenergize the existing circuit and run new conductors back to a point 
where an acceptable connection to the ground is available. (Section 
250.130(C) of the 2002 NEC lists acceptable grounding points.) The risk 
of inadvertently contacting an energized part during the recircuiting 
process is likely to be at least as high as the risk of electric shock 
caused by using the water pipe as an equipment grounding conductor. 
Also, it may not be known which branch circuit receptacles are grounded 
to a water pipe; thus, employees may be introduced to hazards in the 
process of tracing the existing wiring installation. Consequently, the 
final rule allows using a grounded cold water pipe as the equipment 
grounding conductor on branch circuit extensions only in existing 
installations. The final rule would also require such equipment 
grounding connections to be replaced any time work is performed on the 
branch circuit. In such cases, the circuit would need to be deenergized 
anyway, and there would be no increased risk during the installation of 
a new equipment grounding conductor.
---------------------------------------------------------------------------

    \24\ The existing standard permits the use of a grounded cold 
water pipe as an equipment grounding only for extensions of branch 
circuits that do not have an equipment grounding conductor.
---------------------------------------------------------------------------

    Proposed Sec.  1910.304(g)(4) (final Sec.  1910.304(g)(5)) would 
have required the path to ground from circuits, equipment, and 
enclosures to be permanent and continuous. The language in this 
proposed provision is identical to existing Sec.  1910.304(f)(4).
    Several commenters recommended adding the word "effective" in the 
requirement to ensure that the grounding path of the conductor is 
successful in providing a permanent and continuous path to ground (Exs. 
4-4, 4-13, 4-15, 4-17, 4-18, 4-21). These commenters noted that the NEC 
has requirements on effective grounding and has had these requirements 
in the code for many years and that the proposed rule was inconsistent 
with the NEC, NFPA 70E, and other OSHA requirements. For example, Mr. 
Douglas Baxter stated:

    Equipment grounding is important enough for OSHA to require it 
to be effective as stated in the proposal at these locations:
    Page 17817-1910.304(b)(2)(ii) "Receptacles and cord connectors 
having grounding contacts shall have those contacts effectively 
grounded."
    Page 17823-1910.305(c)(5) "Grounding. Snap switches, including 
dimmer switches, shall be effectively grounded and shall provide a 
means to ground metal faceplates."
    It is unclear as to why OSHA believes that electrical circuits 
and equipment (which would be referenced under 1910.304(g)(4)) 
somehow will not present an electrocution hazard if not effectively 
grounded unlike receptacles or snap switches.
    Particularly noteworthy to underscore is the fact that as 
written in the proposal, 1910.304(g)(4) is not consistent with the 
2004 (current) edition of NFPA 70E, nor is it consistent with any 
edition since the original 1979 Edition. The proposal should read 
the same as the 2000 edition of NFPA 70E, as shown above. [Ex. 4-17]

    OSHA believes that the effectiveness of grounding is important and 
will save lives when done properly. Therefore, the final rule, in Sec.  
1910.304(g)(5), requires the equipment grounding conductor to be 
permanent, continuous, and effective.
    The 2002 edition of NEC defines "effectively grounded" in Article 
100 as:

    Intentionally connected to earth through a ground connection or 
connections of sufficiently low impedance and having sufficient 
current-carrying capacity to prevent the buildup of voltages that 
may result in undue hazards to connected equipment or to persons.

    This same definition appears in Part I of the 2000 edition of NFPA 
70E. OSHA proposed a similar definition of "effectively grounded," 
which would have applied to voltages over 600 volts, nominal. To 
clarify the final standard and to maintain consistency with the NEC and 
NFPA 70E, OSHA is adopting the NEC definition of "effectively 
grounded" in Sec.  1910.399 and is applying that definition in the 
final rule to all voltages. The term "effectively grounded" (or the 
equivalent) is used in final Sec. Sec.  1910.304(b)(2)(ii), (g)(5), 
(g)(8)(ii), and (g)(8)(iii), 1910.305(c)(5), and 1910.308(a)(6)(ii), 
(a)(7)(viii), (e)(4)(ii), and (e)(4)(iii). OSHA believes that the 
definition adopted in the final rule accurately describes the intent of 
that term for all of these requirements. The adopted definition merely 
makes explicit what was implicit in the proposal.
    Paragraph (g)(7)(ii) of proposed Sec.  1910.304 (final Sec.  
1910.304(g)(8)(ii) and (g)(8)(iii)) would have recognized several 
methods of grounding electric equipment by means other than direct 
connection to an equipment grounding conductor. This provision would 
have permitted, for installations made before April 16, 1981, only, 
electric equipment to be considered effectively grounded if it was 
secured to, and in metallic contact with, the grounded structural metal 
frame of a building. This paragraph is the same as existing Sec.  
1910.304(f)(6)(ii).
    Several commenters requested that OSHA totally remove the 
structural metal frame of a building as an acceptable grounding method 
(Exs. 3-2, 4-13, 4-15, 4-18, 4-21). For example, NECA believed that 
this grounding technique is obsolete and unsafe (Ex. 3-2). NECA noted 
that 2002 NEC Section 250.136(A) states: "The structural metal frame 
of a building shall not be used as the required equipment grounding 
conductor for ac equipment." Other commenters argued that this 
allowance is incongruent with the 2004 and prior editions of NFPA 70E 
(Exs. 4-13, 4-15, 4-18, 4-21). For example, Mr. Michael Kovacic stated 
that this has been prohibited for ac circuits since the 1978 edition of 
the NEC. He presented the reason for this as follows:

    This requirement [in proposed paragraph (g)(7)(i) for equipment 
grounded by an equipment grounding conductor that is contained 
within the same raceway, cable, or cord, or runs with or encloses 
the circuit conductors] is to keep conductors grouped close together 
so magnetic fields generated by the flow of ac electricity, which 
reacts with the circuit conductors, will cancel each other out, 
thereby minimizing the total circuit impedance for safety reasons 
(preventing electrocution in the event of a breakdown or fault in 
the equipment by rapid operation of the overcurrent device). In the 
case of dc circuits, there are no pulsating magnetic fields and 
consequently no circuit reactance, which increases the circuit 
impedance to negatively affect the grounding path of equipment. [Ex. 
4-18]

    OSHA agrees with these comments. In fact, the Agency provided 
similar rationale in prohibiting the use of the metal structure of a 
building for grounding electric equipment when it adopted the existing 
standard in 1981 (46 FR 4034, 4046, January 16, 1981). However, at that 
time, the Agency also decided not to apply this prohibition 
retroactively, reasoning as follows:

    [F]rom the standpoint of employee safety, installations where 
electric equipment is secured to, and in metallic contact with, the 
grounded structural frame of a building are essentially free of 
electrical shock hazards. This condition occurs because the electric 
equipment enclosures and the metal building frame will be 
approximately at the same potential if a ground fault occurs and 
will provide a measure of employee safety. [46 FR 4046]

    In that rulemaking, OSHA agreed with comments that it would be 
impractical to require changes to installations that had been permitted 
by the NEC for many years before 1978.
    OSHA believes that this rationale continues to apply today. Nothing 
in the record has convinced the Agency that the conclusion drawn in the 
existing standard in 1981 is incorrect. Also, the Agency does not 
believe that the substantial cost to employers of changing these 
grounding connections is worth the slight possible reduction in risk 
associated with moving from the use of the structural metal frame of a 
building to a separate equipment grounding conductor. In addition, in 
actual practice, such a change might not lead to an overall reduction 
in risk at all. To reconfigure a branch circuit and run new conductors 
back to a point where an acceptable connection to the ground is 
available,\25\ an employee would need to deenergize the existing 
circuits connected. An employee could inadvertently contact an 
energized part during the recircuiting process.
---------------------------------------------------------------------------

    \25\ Section 250.130(C) of the 2002 NEC lists acceptable 
grounding methods.
---------------------------------------------------------------------------

    Consequently, the final rule in Sec.  1910.304(g)(8)(iii) continues 
to allow the use of the grounded structural metal frame of a building 
as the equipment grounding conductor for equipment secured to, and in 
metallic contact with, the metal frame only for installations made 
before April 16, 1981. However, unlike the existing standard, the final 
rule requires such grounds to be replaced any time work is performed on 
the branch circuit. In such cases, the circuit needs to be deenergized 
anyway, and there would be no increased risk during the installation of 
a new equipment grounding conductor. Additionally, the costs of 
installing an acceptable equipment grounding conductor in such cases 
would be minimized.

K. Equipment for General Use (Sec.  1910.305)

    Paragraph (a)(2) of proposed Sec.  1910.305 would have applied to 
temporary wiring installations. According to proposed Sec.  
1910.305(a)(2)(iii), temporary installations over 600 volts would only 
be permitted for periods of tests, experiments, or emergencies.
    Northrop Grumman-Newport News objected to this restriction on the 
use of temporary wiring of more than 600 volts (Ex. 3-7). It noted that 
employers performing shipbuilding and ship repair use temporary wiring 
to provide power to the ships that arrive at the shipyard, stating:

    During construction and major overhaul of a vessel, ship and 
shore-based electrical installations may be interconnected. For 
instance, permanent ship electrical systems will typically be 
powered by temporary shore power whenever a ship is not at sea. 
Ships are specifically designed in this manner. [Ex. 3-7-1]

    It noted further that the ships must have their normal power source 
shut down and use the power source from connection points within the 
shipyards, which can be more than 600 volts. It stated that flexible 
cords and cables are used to supply power to these ships for repair and 
maintenance and that they are temporary wiring installations.
    Paragraph (a)(2) of proposed Sec.  1910.305 was taken from Article 
305 of the 1999 NEC and section 3-1.2 in Part I of NFPA 70E-2000. Both 
of these standards permit temporary wiring of more than 600 volts to be 
used for construction in addition to the uses permitted in the OSHA 
proposal. The Agency did not include "construction" as a permitted 
use in the proposal (or, for that matter, in the existing standard) 
because construction work is covered by the construction standards in 
29 CFR Part 1926. However, Northrop Grumman-Newport News's comments 
show that certain types of construction-like activities occur in 
general industry and maritime. The Agency believes that the NEC and 
NFPA 70E intend to permit high-voltage temporary wiring installations 
used for purposes like those described in the Northrop Grumman-Newport 
News comments. Thus, to permit this type of temporary installation and 
to improve consistency with the NEC and NFPA 70E, OSHA has added 
"construction-like activities" to the list of permitted uses for 
high-voltage temporary wiring in final Sec.  1910.305(a)(2)(iii). OSHA 
intends this term to include such construction-like activities as ship 
building and ship repair without regard to whether the activity falls 
under OSHA's construction standards. As noted earlier, construction-
like activities also include cleanup, disaster remediation, and 
restoration of large electrical installations.\26\
---------------------------------------------------------------------------

    \26\ It should be noted that the discussion of the term 
"construction-like activities" applies only to the use of this 
term in Subpart S.
---------------------------------------------------------------------------

    Proposed Sec.  1910.305(a)(3)(v) would have permitted nonmetallic 
cable trays to be installed only in corrosive areas and in areas 
requiring voltage isolation. Two commenters objected to this provision 
(Exs. 3-8, 4-16, 4-22). Mr. Mark Spence, representing Dow Chemical 
Company (Exs. 3-8, 4-16), noted that the corresponding provision in the 
NEC, section 392.3(E), reads as follows:

    In addition to the uses permitted elsewhere in Article 392, 
nonmetallic cable tray shall be permitted in corrosive areas and in 
areas requiring voltage isolation.

    He pointed out that section 392.3 specifically permits cable tray 
systems to be installed as support systems for services, feeders, 
branch circuits, communications circuits, control circuits, and 
signaling circuits. Thus, he concluded that the NEC does not restrict 
the use of nonmetallic cable trays as OSHA's proposal did.
    OSHA agrees with Mr. Spence's comments and has not carried proposed 
Sec.  1910.305(a)(3)(v) into the final rule. This action removes the 
proposed restriction on the use of nonmetallic cable trays. Under the 
final rule, nonmetallic cable trays can be used wherever metallic cable 
trays may be used.
    Mr. Spence also objected to the application of proposed Sec.  
1910.305(j)(2)(iii) to all installations made after March 15, 1972 
(Exs. 3-8, 4-16). This provision would have prohibited nongrounding-
type receptacles from being used for grounding-type attachment plugs. 
He stated that Dow Chemical was concerned that this provision could 
pose problems with existing buildings with two-wire receptacles. He 
reasoned as follows:
    This [proposed provision] is adapted from NFPA 70E Sec.  
420.10(C)(2), which states:

    Non-grounding-type receptacles and connectors shall not accept 
grounding-type attachment plugs.
* * * * *
    OSHA apparently considers that this proposed requirement is 
implicit in the existing Subpart S. The preamble to the proposed 
rule refers to this provision as a "clarification" (69 Fed. Reg. 
at 17788). However, the text of existing Subpart S does not address 
this issue, and Dow could not identify any previous OSHA 
interpretation of its existing requirements which reached the 
conclusion articulated in proposed Sec.  1910.305(j)(2)(iii).
    Accordingly, OSHA should include this requirement (and all 
others that are new to Subpart S) in section 1910.302(b)(4), 
requirements applicable only to installations made after the 
effective date of the final rule. [Ex. 4-16]

    The NEC has required receptacles to be of the grounding type for 
decades. The 1972 NEC, which was adopted by reference in Subpart S from 
March 15, 1972, until April 16, 1981, contained many requirements for 
grounding-type receptacles. For example, Section 210-21(b) of the 1971 
NEC required all receptacles on 15- and 20-ampere branch circuits to be 
of the grounding type. That section also requires grounding-type 
receptacles to be used as replacements for existing nongrounding-type 
receptacles unless it was impractical to reach a source of ground. 
Thus, the vast majority of receptacles installed since 1972 are of the 
grounding type. In addition, equipment supplied with an equipment 
grounding conductor is intended to have that conductor properly 
connected to ground. Using an adapter with such equipment is prohibited 
by existing Sec.  1910.334(a)(3)(iii) if the adapter interrupts the 
equipment grounding conductor. Connecting or altering an attachment 
plug in a manner that prevents proper connection of the equipment 
grounding conductor is prohibited by existing Sec.  1910.334(a)(3)(ii). 
Consequently, OSHA's current standards essentially prohibit connecting 
grounding-type attachment plugs to nongrounding-type receptacles. For 
these reasons, OSHA is carrying proposed Sec.  1910.305(j)(2)(iii) 
forward unchanged into the final rule.
    Proposed Sec.  1910.305(j)(2)(v) would have required a receptacle 
installed outdoors in a location protected from the weather to have an 
enclosure that is weatherproof when the receptacle is covered. A note 
following that provision indicated that a receptacle is considered to 
be in a location protected from the weather where it is located under 
roofed open porches, canopies, marquees, or the like and where it will 
not be subjected to a beating rain or water runoff. OSHA received 
several comments on the language in the note (Exs. 3-2, 4-13, 4-17, 4-
18, 4-21). These commenters argued that the word "beating" is not 
defined making this provision difficult to enforce. They recommended 
that OSHA remove this word from the note.

    The Agency is retaining the term "beating rain" in the final 
rule. The language in the note to final Sec.  1910.305(j)(2)(v) mirrors 
that in section 406.8(A) of the 2002 NEC, which uses the same term in 
describing "locations protected from the weather." More importantly, 
OSHA has determined that the word "beating" as used in the note is 
critical to the meaning of the note itself. Paragraph (j)(2)(v) in 
final Sec.  1910.305 is intended to require weatherproof enclosures to 
ensure that water does not enter or accumulate within the 
enclosure.\27\ If rain can strike the receptacle face directly, water 
will almost certainly enter and accumulate within the enclosure. Thus, 
the term "beating rain" as used in the note means a rain that 
directly contacts the receptacle face. This interpretation is 
consistent with the definition of "damp location" in the final 
rule.\28\
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    \27\ See final Sec.  1910.305(j)(1)(iv) for fixtures, which 
contains a corresponding requirement for fixtures installed in wet 
or damp locations.
    \28\ The definition of "damp location" reads as follows:
    Partially protected locations under canopies, marquees, roofed 
open porches, and like locations, and interior locations subject to 
moderate degrees of moisture, such as some basements, some barns, 
and some cold-storage warehouses.
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    Proposed Sec.  1910.305(j)(3)(iii) would have required each 
electric appliance to be provided with a nameplate with the identifying 
name and the rating in volts and amperes, or in volts and watts. This 
provision also would have required the marking to include frequency 
ratings if the appliance is to be used on specific frequencies. 
Finally, if motor overload protection external to the appliance is 
necessary, this paragraph would have required the appliance to be so 
marked.
    Dow Chemical Company argued that the requirements to mark 
appliances when external overload protection is needed and when the 
appliance must be used on specific frequencies were new requirements 
that should be made applicable only to new installations built after 
the publication of the final rule (Exs. 3-8, 4-16). Dow noted that the 
counterpart in the existing standard, Sec.  1910.305(j)(3)(iii), 
requires the marking to include only the rating in volts and amperes or 
volts and watts. They recommended that proposed Sec.  
1910.305(j)(3)(iii) be included in the list of requirements applicable 
only to installations made after the effective date of the final 
standard.
    The requirement for appliances to be marked with any necessary 
frequency ratings was contained in section 422-30(a) of the 1971 NEC. 
The requirement for marking of the need for external overload 
protection was also contained in section 422-30(a) of the 1971 NEC. In 
addition, the existing OSHA standard in Sec.  1910.303(e) requires 
electric equipment to be marked with voltage, current, wattage, or 
other ratings as necessary. The ratings required by the NEC are 
necessary for the safety of any employee installing or using affected 
appliances. Thus, the marking provisions proposed in Sec.  
1910.305(j)(3)(iii) are not new. The existing rule requires the 
markings implicitly. The final rule simply makes the requirement 
explicit. Therefore, OSHA has not added that paragraph to the list of 
requirements applicable only to new installations given in final Sec.  
1910.302(b)(4).
    Proposed Sec.  1910.305(j)(4)(ii) would have required that each 
motor controller be provided with an individual disconnecting means 
within sight of the controller. However, this provision would have 
permitted a single disconnecting means to be located adjacent to a 
group of coordinated controllers mounted adjacent to each other on a 
multi-motor continuous process machine. In addition, the proposed rule 
would have permitted the controller disconnecting means for motor 
branch circuits over 600 volts, nominal, to be out of sight of the 
controller, if the controller was marked with a warning label giving 
the location and identification of the disconnecting means to be locked 
in the open position.
    Mr. Mark Spence of Dow Chemical requested that the standard allow 
disconnecting means for motor controllers of 600 volts, nominal, or 
less to be out of sight of the controller location if the disconnecting 
means is capable of being locked out (Exs. 3-8, 4-16). He pointed to an 
exception to section 430.102(B) of the 2002 NEC, which, under certain 
conditions, permits disconnecting means to be located out of sight of 
the motor when the disconnecting means is capable of being locked in 
the open position.
    OSHA has not adopted Dow's recommendation. The proposed rule 
requires disconnecting means to be located within sight of the motor 
controller location whereas the NEC exception permits the disconnecting 
means to be out of sight of the motor, not the controller. The 
requirement in 2002 NEC section 430.102(A) for the disconnecting means 
to be within sight of the controller location still exists. Thus, 
proposed Sec.  1910.305(j)(4)(ii) is consistent with the 2002 NEC, and 
OSHA is carrying it forward, unchanged, into the final rule.

L. Specific Purpose Equipment and Installations--Sec.  1910.306

    Proposed Sec.  1910.306(e) read as follows:

    A means shall be provided to disconnect power to all electronic 
equipment in an information technology equipment room. There shall 
also be a similar means to disconnect the power to all dedicated 
heating, ventilating, and air-conditioning (HVAC) systems serving 
the room and to cause all required fire/smoke dampers to close. The 
control for these disconnecting means shall be grouped and 
identified and shall be readily accessible at the principal exit 
doors. A single means to control both the electronic equipment and 
HVAC system is permitted.

    This proposed provision is equivalent to existing Sec.  
1910.306(e), which requires data processing systems to have 
disconnecting means for electronic equipment in data processing or 
computer rooms and for the air conditioning system serving the area.
    Several commenters noted that the 2002 edition of the NEC provided 
an exception to this requirement for integrated systems (Exs. 3-8, 4-
11, 4-16, 4-19). Typifying these comments, the Dow Chemical Company 
argued as follows:

    Using disconnects for information technology systems that are 
part of integrated electrical systems may be an unsafe practice, 
since an orderly shutdown of such systems may be necessary for 
safety. Accordingly, OSHA should amend its proposal to include the 
NEC exception for integrated electrical systems. [Ex. 4-16]

    OSHA agrees with these commenters that providing ready 
disconnecting means for integrated electrical systems can pose greater 
hazards for employees than having the data processing and air 
conditioning systems shut down as part of an orderly process. 
Integrated electrical systems, which are covered by final Sec.  
1910.308(g) provide for deenergizing of electric equipment in an 
orderly fashion to prevent hazards to people and damage to equipment. 
For example, in certain chemical processes, a cooling system is needed 
to maintain control over the chemical process. Deenergizing the cooling 
system for this process while the chemical reaction continues can lead 
to catastrophic failure of containment vessels, which lead to extensive 
property damage and employee injuries. Consequently, OSHA is including 
an exception to final Sec.  1910.306(e) for integrated electrical 
systems covered by Sec.  1910.308(g).

M. Carnivals, Circuses, Fairs, and Similar Events

    Proposed Sec.  1910.306(k) contained new requirements for 
carnivals, circuses, exhibitions, fairs, traveling attractions, and similar 
events. No comments were received concerning these provisions, and OSHA 
is carrying them forward into the final rule unchanged. The 
requirements in final Sec.  1910.306(k), which are based on 
corresponding requirements in NFPA 70E, cover the installation of 
portable wiring and equipment for these temporary attractions. From 
1991 to 2002, OSHA received reports of 46 serious accidents \29\ 
associated with carnivals, circuses, exhibitions, fairs, and similar 
events (Ex. 2-7). Eleven of these accidents, resulting in 10 fatalities 
and 5 injuries, involved electric shock. Eight of those 11 cases (8 
fatalities and 1 injury) involved electric wiring and equipment covered 
by the installation requirements in Subpart S. OSHA believes that the 
new electrical requirements for these events will prevent similar 
accidents in the future.
---------------------------------------------------------------------------

    \29\ These accidents were investigated by OSHA generally in 
response to employer reports of a fatality or three or more 
hospitalized injuries.
---------------------------------------------------------------------------

    In paragraph (k) of final Sec.  1910.306, OSHA is requiring 
mechanical protection of electric equipment (paragraph (k)(1)) and of 
wiring methods in and around rides, concessions, or other units subject 
to physical damage (paragraph (k)(2)). Inside tents and concession 
stands, the electrical wiring for temporary lighting must be secured 
and protected from physical damage (paragraph (k)(3)). In paragraph 
(k)(4), the final rule sets requirements for portable distribution and 
termination boxes. These new provisions will provide more electrical 
safety for employees working in and around this equipment.
    Under final Sec.  1910.306(k)(5), the disconnecting means must be 
readily accessible to the operator; that is, the fused disconnect 
switch or circuit breaker must be located within sight and within 1.83 
meters (6 feet) of the operator for concession stands and rides. This 
provision provides protection by enabling the operator to stop the 
equipment in an emergency. The disconnecting means must also be 
lockable if it is exposed to unqualified persons, to prevent such 
persons from operating it.

N. Zone Classification

    Introduction. Existing Sec.  1910.307 contains OSHA's electrical 
safety requirements for locations that can be hazardous because of the 
presence of flammable or combustible substances. Hazardous locations 
are classified according to the properties of flammable vapors, liquids 
or gases, or combustible dusts or fibers that may be present. These 
locations are designated in the NEC and existing Sec.  1910.307 as one 
of six types: Class I, Division 1; Class I, Division 2; Class II, 
Division 1; Class II, Division 2; Class III, Division 1; and Class III, 
Division 2. This system is called the "division classification 
system," or the "division system." The NEC first addressed this 
system in 1920. The OSHA website has a short but informative paper on 
this topic, which is available at http://www.osha.gov/doc/
outreachtraining/htmlfiles/hazloc.html.
    The 2000 edition of NFPA 70E incorporates an alternative system (in 
addition to the division classification system) for installing electric 
equipment in Class I locations. (Class II locations continue under the 
division system.) This system is called the "zone classification 
system," or the "zone system." The zone system designates three 
classifications: Class I, Zone 0; Class I, Zone 1; and Class I, Zone 2. 
The zone system is based on various European standards that were 
developed by the International Electrotechnical Commission (IEC).\30\ A 
modified version of this system was first adopted into the NEC in the 
1996 edition. Although the zone and division classification systems 
differ in concept, individual equipment can be approved for use under 
both systems when the equipment incorporates protective techniques for 
both systems (as determined by the nationally recognized testing 
laboratory that lists or labels the equipment). Based on the successful 
use of the zone system in European countries for many years and the 
acceptance of the zone system by the NEC and international standards, 
OSHA believes that an installation conforming to requirements for this 
system is as safe as one conforming to requirements for the division 
system.
---------------------------------------------------------------------------

    \30\ The IEC prepares and publishes international standards for 
all electrical, electronic and related technologies. This global 
organization is made up of members from more than 60 participating 
countries, including the U.S.
---------------------------------------------------------------------------

    The zone system incorporated in the final rule is an alternative 
method to the division system; employers may use either system for 
installations of electric equipment in Class I hazardous locations. 
OSHA will recognize the use of the zone system under Sec.  1910.307 and 
any other OSHA standard that references Sec.  1910.307.\31\
---------------------------------------------------------------------------

    \31\ Several OSHA general industry standards outside Subpart S 
require electric equipment to meet the Subpart S requirements for 
Class I, Division 1 or 2 locations. For example, Sec.  
1910.103(b)(3)(ii)(e) requires electric equipment installed in 
separate buildings housing gaseous hydrogen systems to meet the 
Subpart S provisions for Class I, Division 2 locations. Although the 
Agency is not revising any of these other general industry standards 
to specifically accept installations meeting the Subpart S zone 
system requirements, OSHA will consider any nonconformance by an 
installation that the employer can demonstrate is properly 
classified and installed under the Subpart S zone system 
requirements as a de minimis violation.
---------------------------------------------------------------------------

    As noted earlier, OSHA is requiring employers to document the 
designation of hazardous locations within their facilities in final 
Sec.  1910.307(b). The documentation must denote the boundaries of each 
division or zone so that employees who install, inspect, maintain, or 
operate equipment in these areas will be able to determine whether the 
equipment is safe for the location. As noted earlier, OSHA is requiring 
documentation for the division system only for new installations that 
use that system. The document requirement does apply, however, to all 
installations made under the zone system.
    Several commenters supported the proposed requirement for 
documenting installations (Exs. 3-5, 3-9, 5-2). For example, NIOSH 
stated:

    An important addition to the proposed standard is the new 
requirement for employers to document the designation of hazardous 
locations within their facilities, thus allowing workers who 
install, inspect, maintain, or operate equipment in these areas to 
identify the correct equipment or system components to be used to 
ensure worker safety. This requirement would also ensure that the 
employer maintain a record of the boundaries of each hazardous 
location and its classification either under the current division 
system or the proposed zone system. [Ex. 3-9-1]

    One commenter objected to the documentation requirement to the 
extent that it would apply to shipbuilding and ship repair (Ex. 3-7). 
The commenter argued as follows:

    [Proposed Sec.  1910.307] requires documentation of each 
hazardous location, followed by design and installation of equipment 
meeting certain requirements. The standard does not appear to 
consider mobile operations and the difficulty in maintaining 
documentation for an interim operation. For instance, in 
shipbuilding and repair, ship modules and compartments must be spray 
painted. Therefore, at the time the compartment is being painted, it 
may meet the definition of a Class I, Division 2 area.
    There are over 3,000 compartments on an aircraft carrier that 
will be spraypainted at least twice during the course of 
construction. It is not feasible or realistic to expect shipyards to 
maintain a list of precisely which compartments are being 
spraypainted on any particular day. Furthermore, it provides no 
added protection since controls are already established as required 
by 29 CFR 1915, Subpart B. Subpart B--Confined and Enclosed Spaces 
and Other Dangerous Atmospheres, including 1915.13 (Cleaning and 
Other Cold Work), specifies the required controls for spraypainting 
and other cold work, including when explosion proof, self-contained 
lamps or other electric equipment must be approved and used. Based on 
our evaluation that current shipyard standards in Subpart B, 1915 provide 
equal or greater protection and the infeasibility of documenting mobile 
operations, we request that OSHA clarify in the applicability section or 
in the preamble to the final rule that Subpart B is applicable to the 
shipbuilding and repair industry in lieu of 1910.307. [Ex. 3-7-1]

    OSHA does not agree that areas being spraypainted on a temporary 
basis are Class I locations. The areas described by the commenter are 
normally nonhazardous locations that are made hazardous through the 
temporary introduction of flammable gases and vapors; thus, they would 
not be considered a hazardous location. (See 55 FR 32008.) In most 
general industry applications, Sec.  1910.334(d) applies to the 
temporary or occasional use of flammable materials. In the commenter's 
specific case, the shipyard employment standards in Subpart B of 29 CFR 
Part 1915 apply, as the commenter noted (Ex. 3-7-1).\32\ Consequently, 
the employer is not required to document these locations unless the 
painting is done in a location that is hazardous when the spray 
painting operation is not being performed.
---------------------------------------------------------------------------

    \32\ Other provisions that may be applicable in shipyard 
employment include Sec. Sec.  1915.35 and 1915.36.
---------------------------------------------------------------------------

    ORC Worldwide recommended that OSHA clarify what employers must 
include in their documentation of hazardous locations in a nonmandatory 
appendix. As noted earlier, final Sec.  1910.307(b) requires 
documentation that denotes the boundaries of each division or zone. The 
documentation may be in the form of drawings that visually depict the 
boundaries or in text that precisely describes the extent of each 
hazardous location. Examples of acceptable documentation are contained 
in the NEC (see, for example, Figure 514.3, showing the extent of Class 
I, Division 1 and 2 locations surrounding motor fuel dispensers, 
commonly known as gasoline pumps) and in several national consensus 
standards included in Appendix A to Subpart S (see, for example, ANSI/
API RP 505-1997, Recommended Practice for Classification of Locations 
for Electrical Installations at Petroleum Facilities Classified as 
Class I, Zone 0, Zone 1, or Zone 2). Because these standards are 
already listed in Appendix A, OSHA does not believe it is necessary to 
include a separate appendix on the documentation requirements in final 
Sec.  1910.307.
    Changes to OSHA's existing requirements for the division 
classification system. The term "hazardous concentrations" is 
currently used in various definitions of specific hazardous locations 
in Sec.  1910.399. For example, Sec.  1910.399 defines "Class I, 
Division 1," in part, as follows:

    A Class I, Division 1 location is a location: (a) in which 
hazardous concentrations of flammable gases or vapors may exist 
under normal operating conditions * * *

    The final standard replaces the term "hazardous concentrations" 
with "ignitable concentrations" in each of the definitions of Class I 
locations in Sec.  1910.399. This change reflects changes already 
incorporated into the NEC (both the 1999 and 2002 editions) and the 
2000 edition of NFPA 70E to make the definitions more specific about 
the hazard being addressed. The changes, which OSHA does not consider 
to be substantive, make these definitions clearer in addition to making 
the OSHA standard consistent with the latest editions of NEC and NFPA 
70E.
    OSHA is also adding a new paragraph (f) to final Sec.  1910.307 
that lists specific protection techniques under the division system. 
Neither the current Subpart S nor NFPA 70E explicitly list particular 
protection techniques that can be used in the division classification 
system; however, the NEC does provide specific protection techniques 
for installations made under the division classification system in 
various requirements throughout the Articles covering hazardous 
locations. OSHA has listed these techniques in one paragraph in the 
final rule to make the standard easier to use and to provide parallel 
requirements for both the division classification system and the zone 
classification system, which is addressed in final Sec.  1910.307(g). 
Protective techniques other than those listed in final paragraph (f) 
are acceptable if the equipment is: (1) Intrinsically safe as specified 
in Sec.  1910.307(c)(1); (2) approved for the specific hazardous 
location as specified in Sec.  1910.307(c)(2); or (3) of a type and 
design that the employer demonstrates is safe for the specific 
hazardous location as specified in Sec.  1910.307(c)(3). New paragraph 
(f) is intended to clarify the existing OSHA requirements for hazardous 
locations by explicitly listing the types of protective techniques that 
can be used under the division classification system. (The protection 
techniques are required implicitly under the existing standard through 
the requirements for approval and listing or labeling by a nationally 
recognized testing laboratory and through the reference to the NEC in 
the note following existing Sec.  1910.307(c)(3).)
    OSHA received one comment recommending the adoption of additional 
protection techniques for the division system (Ex. 4-22). This 
commenter recommended including protection techniques listed in Section 
500.7 of the 2002 NEC, including nonincendive, hermetically sealed, and 
combustible gas detection protection techniques.
    Paragraph (f)(5) of proposed Sec.  1910.307 (final Sec.  
1910.307(f)(10)) recognized protection techniques not specifically 
listed in the preceding four paragraphs as long as the technique in 
question met proposed Sec.  1910.307(c). Because the techniques 
mentioned by the commenter meet the 2002 NEC requirements for Class I 
hazardous locations, those techniques would have been recognized under 
proposed Sec.  1910.307(f)(5). However, to clarify the standard, OSHA 
has included all the protective techniques listed in Section 500.7 of 
the 2002 NEC in final Sec.  1910.307(f).
    Brief background and description of the zone system. The zone 
system stemmed from the independent efforts of countries in Europe and 
elsewhere to develop an area classification system to address safety in 
locations containing hazardous substances. The IEC formalized these 
efforts into the zone system, which is now used to classify the 
majority of the world's hazardous location systems.\33\
---------------------------------------------------------------------------

    \33\ Brenon, M., Kelly, P., McManama, K., Klausmeyer, U., Shao, 
W., Smith, P., "The Impact of the IECEx Scheme on the Global 
Availability of Explosion Protected Apparatus," Record of 
Conference Papers of the 1999 Petroleum and Chemical Industry 
Technical Conference, September 13-15, 1999, Paper No. PCIC-99-07, 
pp. 99-109.
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    Article 505 of the 1996 NEC included requirements for the U.S. 
version of the zone system for the first time. The 2000 edition of NFPA 
70E includes requirements for the zone system based on the 1999 version 
of the NEC. OSHA is adopting zone system rules that are based on these 
NFPA 70E provisions. This will permit electric equipment approved for 
use in hazardous locations to be used in U.S. workplaces, under either 
the division or zone system.
    Major differences between the division classification system and 
the zone classification system. The zone system can best be described 
by comparing it with the division system. Both systems characterize 
locations by the likelihood and circumstances under which flammable 
gases or vapors exist.
The systems both define the types of gases or vapors that may exist and 
categorize them under a number of groups. Each system specifies an 
allowable range of operating temperature, and corresponding 
requirements, for electric equipment used in a particular division or 
zone.
    In contrast to the division system, however, the zone system is 
only used to classify areas that are hazardous because of the presence 
of flammable gases or vapors (Class I locations). The division system 
must be used to classify areas that may contain combustible dusts or 
easily ignitable fibers or flyings (Class II and III locations, 
respectively).
    The zone system defines three types of Class I locations (Zones 0, 
1, and 2) rather than two locations under the division system 
(Divisions 1 and 2). Zones 0 and 1 equate to Division 1, whereas Zone 2 
equates to Division 2. In a Class I, Division 1 location, flammable 
gases or vapors are or may be present in the air in ignitable 
concentrations. In a Class I, Zone 1 location, ignitable concentrations 
of flammable gases or vapors are not always present, but such 
concentrations may exist periodically even under normal conditions. By 
contrast, in a Class I, Zone 0 location, such gases or vapors are 
present either continuously or for long periods. (See Table 2.) Thus, a 
Class I, Zone 0 location is, in essence, a worst-case Class I, Division 
1 location.
    Each system classifies flammable gases and vapors into a number of 
groups. The division system has four such groups, designated A, B, C, 
and D, with group A containing the most volatile substances, and groups 
B, C, and D containing gases or vapors that are progressively less 
volatile. The zone system has three such groups, designated IIA, IIB, 
and IIC, with group IIC containing the most volatile gases, and groups 
IIA and II B containing gases or vapors that are progressively less 
volatile. Substances classified under groups A and B in the division 
system generally fall under group IIC of the zone system. However, some 
differences exist between the groups in the two systems. Thus, 
regardless of the classification system being used, equipment intended 
for use in a Class I hazardous location must indicate the groups for 
which it is approved, as required by final Sec.  1910.307(c)(2)(ii) and 
(g)(5)(ii). Table 2 summarizes the similarities and differences between 
the two systems.
    The other major differences concern the allowable protection 
schemes and the maximum allowable surface temperature of equipment 
under each system. The protection schemes acceptable for each division 
and zone are listed in Table 3, and the remainder of this paragraph 
discusses the differences in maximum allowable temperature. According 
to the NEC, equipment is acceptable for a hazardous location only if 
its surface temperatures will not approach the ignition temperature, or 
more specifically the autoignition temperature, of the particular gases 
and vapors that might be present in that location. There are 14 
temperature limits, and corresponding identification codes, under the 
division system. Each limit specifies the maximum surface temperature 
for equipment labeled with the matching code. There are six such 
temperature limits and corresponding identification codes under the 
zone system. The six zone system limits correspond directly to 6 of the 
14 division system temperature limits. However, as shown in Table 2, 
the remaining eight division temperature limits have values 
intermediate to the six zone system temperature limits. For example, 
the division system has 4 intermediate temperature limits, 215 [deg]C, 
230 [deg]C, 260 [deg]C, and 280 [deg]C (T2D, T2C, T2B, and T2A, 
respectively), between the zone system's temperature limits of 200 
[deg]C (T3) and 300 [deg]C (T2). Equipment approved for one of these 
intermediate values may be used under the zone system only for the 
higher (in temperature) of the two closest zone system values. For 
example, equipment marked T2A under the division system, which has a 
maximum surface temperature of 280 [deg]C, could only be used in 
locations where the ignition temperature of the substance is greater 
than or equal to the T2 value, which is 300 [deg]C. In essence, T2A 
equipment becomes derated to T2 equipment when it is installed using 
the zone classification system. It could not be used in zone-classified 
locations where the ignition temperature of the substance is less than 
or equal to the T3 value, which is 200 [deg]C, because the equipment 
could become hot enough to cause ignition.
    More details on the differences in gas groups. In the 1999 NEC, the 
definitions for each of the division system gas and vapor groups, 
except Group A,\34\ were changed to make them comparable to the 
definitions of the zone system groups. A gas or vapor is classified in 
the division system's Group B, C, or D or the zone systems Group IIC, 
IIB, or IIA based on the gas's or vapor's maximum experimental safe gap 
(MESG) \35\ or its minimum igniting current ratio (MIC ratio).\36\ 
These values are established under standard experimental conditions for 
each gas and vapor.
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    \34\ Acetylene is the only Group A gas under the division 
system.
    \35\ The MESG is the maximum clearance between two parallel 
metal surfaces that has been found, under specified test conditions, 
to prevent an explosion in a test chamber from being propagated to a 
secondary chamber containing the same gas or vapor at the same 
concentration.
    \36\ The MIC ratio is the ratio of the minimum current required 
from an inductive spark discharge to ignite the most easily 
ignitable mixture of a gas or vapor, divided by the minimum current 
required from an inductive spark discharge to ignite methane under 
the same test conditions.
---------------------------------------------------------------------------

    The 1999 NEC indicates two factors that may affect MESG and MIC 
values: (1) Lower ambient temperatures (lower than minus 25 [deg]C or 
minus 13 [deg]F), and (2) oxygen enriched atmospheres. The 1999 NEC 
Handbook states that the latter factor can drastically change the 
explosion characteristics of materials. Such an atmosphere lowers the 
minimum ignition energy, increases the explosion pressure, and can 
reduce the maximum experimental safe gap. These factors would make it 
unsafe to use otherwise approved "intrinsically safe" and 
"explosion-proof" equipment, unless the equipment has been tested for 
the specific conditions involved. Employers must ensure that the 
equipment approval is valid for the actual conditions present where the 
equipment is installed. This is required generally for all electric 
equipment. However, it is essential in hazardous locations because of 
the dire consequences that may result.
    Rationale for adopting the zone system requirements. As stated 
earlier, the zone system has been accepted in many countries. Such 
international acceptance has meant that U.S. manufacturers of electric 
equipment suitable for installation in hazardous locations have had to 
ensure that their equipment met the zone system requirements if they 
wished to sell such equipment in zone-system countries in addition to 
meeting the U.S. division system requirements. Also, U.S. employers 
that had hazardous locations in their workplaces have sought to use 
equipment approved for use only in zone-classified locations in this 
country. This, in turn, led NFPA to incorporate the zone system in the 
NEC starting in the 1996 edition.
    OSHA has determined that employees can be protected from the 
hazards of explosion in Class I hazardous locations by the installation 
of electric equipment following the latest NEC requirements for the 
zone classification system (Article 505 of the 2002 NEC). Therefore, 
the Agency is incorporating the zone system in this revision of the 
electrical installation requirements in Subpart S. Under the final 
standard, employers are able to comply with either the zone classification 
system or the division system for Class 1 hazardous locations.
    New Sec.  1910.307(g) and related definitions. In the final rule, 
OSHA is adding a new paragraph (g) to final Sec.  1910.307 that covers 
the zone classification system. This new paragraph addresses the 
following topics related to the zone classification system: scope; 
location and general requirements; protection techniques; special 
precaution; and listing and marking. A brief description of the 
contents of each paragraph follows.
    Paragraph (g)(1) permits employers to use the zone classification 
system as an alternative to the division classification system. As 
explained in paragraph (a)(4), the requirements in final Sec.  1910.307 
that are specific to installations built under the division 
classification do not apply to installations built under the zone 
classification system. Thus, paragraph (c), electrical installations; 
paragraph (d), conduits; paragraph (e), equipment in Division 2 
locations; and paragraph (f), protection techniques do not apply to 
installations built under the zone system. Paragraph (g) contains 
counterparts to each of these requirements.
    Paragraphs (g)(2)(i) and (g)(2)(ii) describe how hazardous 
locations are classified under the zone system. The employer must 
consider each individual room, section, or area separately and must 
designate locations according to the specific properties of the 
flammable gases, liquids, or vapors that might be present. The same 
requirements apply to the division system. (See final Sec.  
1910.307(a).)
    Paragraphs (g)(2)(iii) and (g)(2)(iv) require that conduit threads 
be of certain types and that connections be made wrench tight. These 
provisions ensure that there is no arcing across conduit connections in 
the event that they have to carry fault current. Paragraph (d) contains 
similar requirements for division system installations.
    Paragraph (g)(3) of final Sec.  1910.307 presents the protection 
techniques that are acceptable in zone-classified hazardous locations. 
Electric equipment in these locations must incorporate at least one of 
these protection techniques, and the equipment must be approved for the 
specific hazardous location. The protection techniques listed in final 
Sec.  1910.307(g)(3) have been taken directly from NFPA 70E-2000.
    OSHA received two comments on this proposed provision (Exs. 4-11, 
4-19). These comments recommended that OSHA modify proposed paragraph 
(g)(3) to include Exception 4 to Section 505.20(C) of the 2002 NEC, 
which states: "In Class I, Zone 2 locations, the installation of open 
or nonexplosion-proof or nonflame-proof enclosed motors, such as 
squirrel-cage induction motors without brushes, switching mechanisms, 
or similar arc-producing devices that are not identified for use in a 
Class I, Zone 2 location shall be permitted." They argued that the 
2002 NEC does not require these types of motors to use one of the 
listed protection types.
    OSHA disagrees with these comments. The exception to which these 
commenters pointed is to a requirement that equipment in Class I, Zone 
2 locations be specifically listed and marked as suitable for the 
location. (See 2002 NEC Section 505.20(C).) Final Sec.  1910.307(g)(3), 
however, is based on 1999 NEC Section 505-4, which corresponds to 2002 
NEC Section 505.8. The types of motors mentioned by the commenters fall 
under protection technique "n" (known as "type of protection"). 
This protection technique is defined in Section 505.2 of the 2002 NEC 
as "Type of protection where electrical equipment, in normal 
operation, is not capable of igniting a surrounding explosive gas 
atmosphere and a fault capable of causing ignition is not likely to 
occur." A nonexplosion-proof motor without arc producing devices must 
also have a surface temperature under normal operating conditions that 
will be lower than the ignition temperature of the gas or vapor 
involved to be safe in a Class I, Zone 2 location. By definition, these 
are locations that are subject, albeit infrequently, to the 
introduction of hazardous quantities of flammable gases or vapors. If 
the surface temperature of the motor is too high, an explosion could 
result in those unusual but foreseeable situations involving hazardous 
accumulations of flammable gases or vapors. Thus, OSHA concludes that 
motors addressed by the NEC exception must still meet the criteria 
imposed by protection technique "n."
    On the other hand, it appears that such motors are acceptable under 
the 2002 NEC even though they are not marked with any protection 
technique.\37\ Proposed Sec.  1910.307(g)(5) would have required all 
equipment installed under the zone classification system to be marked 
either with an acceptable class and division marking or with relevant 
class and zone markings. Based on the 2002 NEC requirements for 
installing and marking electric equipment in installations made under 
the zone classification system, OSHA has determined that it is 
unnecessary for certain types of equipment to be marked as required by 
final Sec.  1910.307(g)(5). Therefore, in paragraph (g)(5)(ii)(C), the 
Agency has added an exception to final paragraph (g)(5) for electric 
equipment that the employer demonstrates will provide protection from 
the hazards arising from the flammability for the gas or vapor and zone 
of location involved and will be recognized by employees as providing 
such protection. Employers may point to the NEC as evidence that the 
equipment is safe.
---------------------------------------------------------------------------

    \37\ The marking requirement is contained in Section 505.9(C) of 
the 2002 NEC.
---------------------------------------------------------------------------

    Paragraph (g)(4) of final Sec.  1910.307 sets special precautions 
that must be taken with respect to hazardous locations classified under 
the zone system. First, the classification of areas and the selection 
of equipment and wiring must be under the supervision of a qualified 
registered professional engineer. This provision is contained in NFPA 
70E-2000 and in the 1999 NEC. Because the zone system has been 
permitted in the U.S. only since 1997,\38\ employers and installers in 
this country have had relatively little experience with installations 
made using the zone classification system. The technical committees 
that developed NFPA 70E and the NEC have determined that, for the zone 
system, it is essential for competent persons to classify the hazardous 
locations and select equipment for those locations. OSHA agrees with 
the consensus determination by these committees, which are composed of 
members (such as NRTLs, electric equipment manufacturers, electrical 
contractors, and affected employee organizations) with expertise in 
electrical safety in hazardous locations.
---------------------------------------------------------------------------

    \38\ As noted earlier, the zone system was first incorporated 
into the NEC in the 1996 edition. This edition was adopted by 
various governmental jurisdictions beginning in 1997. Installations 
made using the zone system were not permitted by these jurisdictions 
before then. In addition, the existing OSHA standard does not permit 
classifying hazardous locations under the zone system, and employers 
have not been certain that installations made using the zone 
classification systems would be acceptable to OSHA.
---------------------------------------------------------------------------

    Some commenters objected to the requirement that the classification 
of areas and selection of equipment and wiring methods be under the 
supervision of a qualified registered professional engineer (Exs. 3-5, 
3-8, 4-16). ASSE argued that qualified electricians and safety 
professionals should be permitted to classify areas and select equipment 
and wiring methods for installations made under the zone classification system 
(Ex. 3-5). They further stated that not all professional engineers possess the 
electrical background to qualify for these tasks. Dow Chemical Company urged the 
Agency to permit any qualified person to classify areas and select equipment for 
zone-classified locations. They pointed to the action the NFPA took in 
adopting new Article 506 for the next edition of the NEC (the 2005 
NEC). Dow stated that this new article contains Sec.  506.6, which 
reads as follows:

    Classification of areas, engineering and design, selection of 
equipment and wiring methods, installation, and inspection shall be 
performed by qualified persons [Ex. 3-8].

    Thus, Dow argues that NFPA has endorsed using qualified persons not 
just qualified registered professional engineers to make these 
determinations.
    OSHA does not agree with the rationale put forth by ASSE and Dow. 
The NEC design requirements for installations made under the zone 
classification system are general, performance-oriented provisions that 
demand sound engineering judgment on the part of persons responsible 
for designing the installation. Paragraph (g)(4) of final Sec.  
1910.307 requires the services of a qualified registered professional 
engineer to ensure that the person primarily responsible for the design 
of the installation is particularly suited to the task. A registered 
professional engineer who does not have an understanding of the 
construction and operation of the equipment and the hazards involved in 
zone-classified locations would not meet the criteria spelled out in 
final Sec.  1910.307(g)(4) and in the definition of "qualified 
person." \39\ The NEC requirements for installations made under the 
division classification system, on the other hand, are far more 
detailed and are more specification oriented. Because the division 
system has been in existence in this country for so long, because 
electricians and safety professionals have had decades to become 
familiar with it, and because (as noted earlier) many consensus 
standards specifically delineate the boundaries of locations classified 
under the division system, it is much easier for an electrician or a 
safety professional with a strong electrical background to properly 
classify a hazardous location under the division classification system. 
Furthermore, because the NEC division-system requirements are so 
detailed, it is easy for an electrician or a safety professional to 
select equipment appropriate for such a location. It is considerably 
more difficult to perform those same duties under the zone 
classification system. It should be noted that the 2005 edition of the 
NEC was not available while the rulemaking record was open. However, 
the new article in the 2005 NEC cited by Dow does not apply to Class I 
locations, which are locations made hazardous because of the presence 
of flammable gases or vapors, but to Class II and III locations,\40\ 
which are locations made hazardous because of the presence of 
combustible dust, fibers, and flyings. Class II and III locations are 
not as hazardous as Class I locations and do not warrant the same 
degree of caution. For these reasons, OSHA is carrying Sec.  
1910.307(g)(4) into the final rule unchanged.
---------------------------------------------------------------------------

    \39\ The definition of "qualified person" in final Sec.  
1910.399 reads as follows: "One who has received training in and 
has demonstrated skills and knowledge in the construction and 
operation of the electric equipment and installations and the 
hazards involved."
    \40\ Under the zone classification system, these locations are 
categorized simply as Zone 20, 21, and 22 locations, with no 
reference to the class of the location.
---------------------------------------------------------------------------

    Paragraph (g)(4) also indicates when it is safe to have locations 
classified using the division system on the same premises as locations 
classified under the zone system and vice versa. These provisions are 
also taken from NFPA 70E-2000.
    Several commenters pointed out an error in a metric conversion in 
the note to proposed Sec.  1910.307(g)(4) (Exs. 4-13, 4-15, 4-18, 4-
21). The proposed note listed -13 [deg]F as the English unit equivalent 
to -20 [deg]C. The correct English value is -4 [deg]F. The Agency has 
made this correction in the final rule.
    Paragraph (g)(5) of final Sec.  1910.307 contains requirements for 
marking equipment that is approved for hazardous locations classified 
under the zone system. These provisions are comparable to the 
corresponding marking requirements under the division system, but 
reflect the need to provide information necessary for safely installing 
equipment in a zone-classified location. As noted earlier, paragraph 
(g)(5)(ii)(C) contains an exception for equipment that the employer 
demonstrates will provide protection from the hazards arising from the 
flammability of the vapors, liquids, or gasses involved and that will 
be recognized as such by employees.
    Equivalence of systems and permitted protection techniques. Table 2 
shows the general equivalence between the two classification systems. 
It should be noted, however, that a given area classified under one 
system is not permitted to overlap an area classified under the other 
system. For example, although Division 2 and Zone 2 are basically 
equivalent classifications, under the final standard a Zone 2 location 
is permitted to touch a Division 2 location, but the two locations are 
not permitted to overlap. This ensures that equipment installed and 
maintenance performed in these locations are appropriate for the 
conditions in each location.\41\
---------------------------------------------------------------------------

    \41\ Division 2 and Zone 2 are basically equivalent 
classifications, but there are some differences in what types of 
equipment are acceptable in each of those locations. See, for 
example, the earlier discussion on maximum allowable surface 
temperatures.

 Table 2.--Equivalence of Hazardous (Classified) Location Systems, Class
                        I Locations Only \1\ \2\
------------------------------------------------------------------------
            Category                Division system       Zone system
------------------------------------------------------------------------
Locations.......................  Division 1........  Zone 0, Zone 1.
                                  Division 2........  Zone 2.
Gas Groups (see Table 3 since     A, B..............  IIC (not fully
 systems are not fully                                 equivalent to
 equivalent).                                          Groups A and B).
                                  C.................  IIB (not fully
                                                       equivalent to
                                                       Group C).
                                  D.................  IIA (not fully
                                                       equivalent to
                                                       Group D).
Temperature Codes...............  T1 (< =450 [deg]C).  T1 (< =450 [deg]C).
                                  T2 (< =300 [deg]C).  T2 (< =300 [deg]C).
                                  T2A, T2B, T2C, T2D  T2
                                   (< =280, < =260,      (effectively).\3\
                                   < =230, < =215
                                   [deg]C).
                                  T3 (< =200 [deg]C).  T3 (< =200 [deg]C).
                                  T3A, T3B, T3C       T3
                                   (< =180, < =165,      (effectively).\3\
                                   < =160 [deg]C).
                                  T4 (< =135 [deg]C).  T4 (< =135 [deg]C).
                                  T4A (< =120 [deg]C)  T4
                                                       (effectively).\3\
                                  T5 (< =100 [deg]C).  T5 (< =100 [deg]C).
                                  T6 (< =85 [deg]C)..  T6 (< =85 [deg]C).
------------------------------------------------------------------------
Notes to Table 2:
\1\ Use of the equivalence shown in the table above must be done only as
  permitted by Sec.   1910.307.
\2\ The zone classification system described in this preamble does not
  cover Class II or Class III locations.
\3\ See the discussion of maximum allowable surface temperatures earlier
  in the preamble.

    Table 3 describes which protection techniques may be used in which 
classified locations.

 Table 3.--Permitted Protection Techniques (Design Criteria) in Class I
                                Locations
------------------------------------------------------------------------

------------------------------------------------------------------------
                                            Zone 0:
                                            --intrinsically safe "ia".
                                            --Class I, Division 1
                                             intrinsically safe.


Division 1:                                 Zone 1:
--explosion-proof.                          --flameproof "d".
--purged and pressurized (Type X or Y).     --purged and pressurized.
--intrinsically safe.                       --intrinsically safe "ib".
                                            --oil immersion "o".
                                            --increased safety "e".
                                            --encapsulation "m".
                                            --powder filling "q".
                                            --any Class I, Division 1
                                             method.
                                            --any Class I, Zone 0
                                             method.
------------------------------------------------------------------------
Division 2:                                 Zone 2:
--purged and pressurized (Type Z).          --non-sparking "nA".
--intrinsically safe.                       --protected sparking "nC".
--nonincendive.                             --restricted breathing
--oil immersion.                             "nR".
--hermetically sealed.                      --any Class I, Division 1 or
--any Class I, Zone 0 or 1 method.           2 method.
--any Class I, Zone 0, Zone 1, or Zone 2    --any Class I, Zone 0 or 1
 method.                                     method.
------------------------------------------------------------------------

    Listing and labeling by NRTLs. Paragraph (a) of final Sec.  
1910.303 continues the existing requirement that all electric equipment 
be approved. While OSHA believes that approval is necessary for all 
electric equipment, the need for third-party approval of electric 
equipment in hazardous locations is particularly crucial. The 
techniques for ensuring safety in hazardous locations require careful 
manufacturing and testing of products because tolerances are tight and 
the margin for error is slim. Thus, OSHA's general industry electrical 
installation standard has always called for equipment approval, which 
generally requires listing or labeling by a nationally recognized 
testing laboratory (NRTL) of equipment installed in hazardous 
locations.\42\ Under 29 CFR 1910.7, OSHA recognizes testing 
organizations that are capable of performing third-party testing for 
safety and designates them as NRTLs. Employers may use products listed 
by NRTLs to meet OSHA standards that require testing and certification. 
NRTLs test and certify equipment to demonstrate conformance to 
appropriate test standards. Many of these test standards cover 
equipment used in hazardous locations.
---------------------------------------------------------------------------

    \42\ Equipment that is of a type that no nationally recognized 
testing laboratory accepts as being safe can achieve approval 
through acceptance by a Federal, State, or local authority having 
jurisdiction over the safety of electrical installations. Custom-
made equipment can gain approval through testing by the equipment 
manufacturer. However, these two modes of approval are rare for 
equipment installed in hazardous locations. Federal, State, and 
local authorities generally look to NRTLs for equipment approval, 
and this is even more true for equipment installed in hazardous 
locations. This type of equipment must be tested to ensure that it 
is safe, and these authorities generally do not have the capability 
to do electrical testing. Custom-made equipment, by its nature, is 
very rare.
    Existing Sec.  1910.307(b) also recognizes equipment that is 
"safe for the hazardous (classified) location." This provision 
permits equipment that is approved for installation in nonhazardous 
locations if the employer demonstrates that the equipment will 
provide protection from the hazards arising from the combustibility 
and flammability of vapors, liquids, gases, dusts, or fibers. This 
condition exists only in limited circumstances as demonstrated by 
the 2002 NEC, which permits only certain types of general-purpose 
equipment in hazardous locations and then only under limited 
conditions. For example, Section 501.8(B) of the 2002 NEC permits 
nonexplosionproof enclosed motors in Class I, Division 2 locations 
if they have no brushes, switching mechanisms, or similar arc-
producing devices and if exposed motor surfaces do not exceed 80 
percent of the ignition temperature of the gas or vapor involved.
---------------------------------------------------------------------------

    OSHA's existing requirements for hazardous locations in Subpart S 
only address locations classified under the division system, and NRTLs 
perform testing based on that system. However, test standards currently 
used by NRTLs to test equipment in hazardous locations classified by 
division are not automatically appropriate for testing such equipment 
for use under the zone system. These current test standards are based 
on protective techniques used for equipment designed for use under the 
division system and do not contain criteria for protective techniques 
used in the zone system. Electric equipment that has been approved by 
an NRTL for use in division-classified hazardous locations may be capable 
of igniting flammable gases or vapors when used inappropriately in 
zone-classified locations. Such hazardous equipment can cause a catastrophic 
explosion and the deaths of and injuries to many employees. In recognizing 
laboratories under Sec.  1910.7 to test products designed for installation 
in zone-classified locations, OSHA will ensure that the proper test standards 
are used and look closely at the capability of the laboratory to 
perform testing under those standards.
    Effects and changes to other Part 1910 standards (Sec. Sec.  
1910.103, 1910.106, 1910.107, 1910.110, 1910.178, and 1910.253). A 
number of other OSHA standards under 29 CFR Part 1910 contain 
references to or requirements related to Sec.  1910.307. Some of these 
standards refer only to hazardous locations classified under the 
division system. The standards particularly affected are as follows:
    Sec.  1910.103(b)(3)(ii)(e) and (b)(3)(iii)(e), (c)(1)(ix)(a), and 
(c)(1)(ix)(b);
    Sec.  1910.106(d)(4)(iii), (e)(7)(i)(b), (e)(7)(i)(c), 
(e)(7)(i)(d), (g)(1)(i)(g), (g)(4)(iii)(a), (h)(7)(iii)(b), and 
(h)(7)(iii)(c);
    Sec.  1910.107(c)(6), (c)(8), (j)(4)(iv);
    Sec.  1910.110(b)(17)(v);
    Sec.  1910.178(c)(2)(iv) and (q)(2); and
    Sec.  1910.253(f)(4)(iv)(B) and (f)(6)(v).
    OSHA is not modifying any of these standards in this rulemaking. 
Several of these requirements call for designating particular locations 
as Class I, Division 1 or Division 2 locations, and OSHA believes that 
revising them would not be straightforward and would be too complicated 
to do in this rulemaking. For example, Sec.  1910.103(c)(1)(ix)(a) 
requires electric wiring and equipment "located within 3 feet of a 
point where connections are regularly made and disconnected, shall be 
in accordance with Subpart S of this Part, for Class I, Group B, 
Division 1 locations." Under the zone system, this location would 
likely be partly a Zone 0 location and partly a Zone 1 location. Thus, 
this requirement cannot be revised by a straightforward substitution of 
"Zone" for "Division." Similar problems exist in revising the other 
requirements. OSHA will make a case-by-case determination of whether a 
particular installation under the zone classification system meets the 
criteria for a de minimis violation based on: (1) Evidence the employer 
provides to show that the installation is as safe as it would be if it 
complied with Subpart S requirements for installations made under the 
division system and (2) the extent to which the employer's designation 
of Class I, Zone 0, 1, and 2 locations is consistent with sound 
engineering practices, as evidenced by national consensus and industry 
standards.

O. Remote Control, Signaling, Power-Limited, and Fire Alarm Circuits

    Proposed Sec.  1910.308(c) addressed Class 1, 2, and 3 remote 
control, signaling, and power-limited circuits. The American Petroleum 
Institute (API) and Dow Chemical Company noted that Section 725.55 of 
the 2002 NEC specifically permits many types of installations that are 
not listed in OSHA's proposal (Exs. 3-8, 4-11). They recommended that 
the OSHA standard also list permitted uses for these types of circuits 
for consistency with the NEC.
    The provision in the 2002 NEC to which API and Dow referred 
(Section 725.55) does not actually list permitted uses. Rather, this 
provision contains requirements for separating different classes of 
circuits, with the method of separation differing in some respect for 
the various types of installations.\43\ For example, Section 725.55(B) 
states, "Class 2 and Class 3 circuits shall be permitted to be 
installed together with Class 1, non-power-limited fire alarm and 
medium power network-powered broadband communications circuits where 
they are separated by a barrier [emphasis added]."
---------------------------------------------------------------------------

    \43\ The title of Sec.  725.55 of the 2002 NEC is "Separation 
from Electric Light, Power, Class 1, Non-Power-Limited Fire Alarm 
Circuit Conductors, and Medium Power Network-Powered Broadband 
Communications Cables."
---------------------------------------------------------------------------

    Proposed Sec.  1910.308(c), which was nearly identical to Section 
6.3.1.3.1.1 of NFPA 70E-2000, read as follows:

    Cables and conductors of Class 2 and Class 3 circuits may not be 
placed in any cable, cable tray, compartment, enclosure, manhole, 
outlet box, device box, raceway, or similar fitting with conductors 
of electric light, power, Class 1, nonpowerlimited fire alarm 
circuits, and medium power network-powered broadband communications 
cables.

    This provision in the proposal and the corresponding one in NFPA 
70E were taken from 1999 NEC Section 725-54(a)(1), which contains the 
same basic requirement, but which also contains six exceptions to this 
general rule. All the exceptions permit cables and conductors of Class 
2 and Class 3 circuits to be placed in one of the listed enclosures 
with a higher powered circuit as long as an extra barrier of one form 
or another is installed to separate the two different classes of 
circuits. Consequently, OSHA agrees with the commenters that the 
proposal could have unnecessarily restricted the installation of Class 
2 and Class 3 circuits. On the other hand, adopting the specific 
language in the NEC (either the 1999 edition or the 2002 edition, which 
converted the exception into separate rules) would make the OSHA 
standard too detailed and specification oriented. To address API's and 
Dow's concerns, OSHA has decided to incorporate the exceptions in 1999 
NEC Section 725-54(a)(1) in performance terms. Final Sec.  
1910.308(c)(3) thus reads as follows:

    Cables and conductors of Class 2 and Class 3 circuits may not be 
placed in any cable, cable tray, compartment, enclosure, manhole, 
outlet box, device box, raceway, or similar fitting with conductors 
of electric light, power, Class 1, nonpower-limited fire alarm 
circuits, and medium power network-powered broadband communications 
cables unless a barrier or other equivalent form of protection 
against contact is employed. [Emphasis added.]

    Employers can look to the NEC to help determine acceptable methods 
of separating Class 2 and Class 3 circuits from electric light, power, 
Class 1, and nonpower-limited fire alarm circuit conductors and from 
medium power network-powered broadband communications cables.
    OSHA received a similar comment on proposed Sec.  1910.308(d)(3) 
recommending that the provision mention all the permitted uses for fire 
alarm circuits listed in 2002 NEC Section 760.55 (Ex. 4-22). The Agency 
has rejected this recommendation for the same reasons it rejected the 
recommendation concerning remote control, signaling, and power-limited 
circuits.
    Dow Chemical Company objected to proposed Sec.  1910.308(d)(3)(iii) 
(Exs. 3-8, 4-16). They stated their objections as follows:

    The current provision, section 1910.308(d)(4), has a 2-inch 
requirement for separation of power-limited conductor locations with 
an option for alternative protections (emphasis added):
    Power-limited conductor location. Where open conductors are 
installed, power-limited fire protective signaling circuits shall be 
separated at least 2 inches from conductors of any light, power, 
Class 1, and non-power-limited fire protective signaling circuits 
unless a special and equally protective method of conductor 
separation is employed.

    The proposed revision of that 2-inch requirement does not have that 
option:

    Power-limited fire alarm circuit conductors shall be separated 
at least 50.8 mm (2 in.) from conductors of any electric light, 
power, Class 1, nonpower-limited fire alarm, or medium power 
network-powered broadband communications circuits.
    The preamble characterizes this change as a clarification of 
existing requirements (69 FR at 17792). This is not a clarification, 
however, but a limitation.
    As a significant change, at a minimum this provision should be 
applicable only to installations after the effective date of the final 
rule under Sec.  1910.302(b)(4). The proposed rule lists all of Sec.  
1910.308(d) as being triggered in installations made after April 16, 
1981, per proposed Sec.  1910.302(b)(3).
    Further, this deletion of the option for using equally protective 
methods is not justified and should not be adopted. NEC Sec.  
800.52(A)(2) provides that option today with two exceptions. That 
provision reads:

    Other Applications. Communications wires and cables shall be 
separated at least 50 mm (2 in.) from conductors of any electric 
light, power, Class 1, non-power-limited fire alarm, or medium power 
network-powered broadband communications circuits.
    Exception No. 1: Where either (1) all of the conductors of the 
electric light, power, Class 1, non-power-limited fire alarm, and 
medium power network-powered broadband communications circuits are 
in a raceway or in metal-sheathed, metal-clad, nonmetallic-sheathed, 
Type AC, or Type UF cables, or (2) all of the conductors of 
communications circuits are encased in raceway.
    Exception No. 2. Where the communications wires and cables are 
permanently separated from the conductors of electric light, power, 
Class 1, non-power-limited fire alarm, and medium power network-
powered broadband communications circuits by a continuous and firmly 
fixed nonconductor, such as porcelain tubes or flexible tubing, in 
addition to the insulation on the wire. [Ex. 3-8]

    Dow further noted that NFPA provides similar exceptions to the 
corresponding provision in that standard. They concluded their comments 
as follows:

    The availability of such options is important because computer 
rooms, control rooms, and communications closets may have mixed 
wiring under the floor that relies on the availability of those 
exceptions.
    OSHA should not take away the options present in the existing 
rule, particularly since they are supported by both the NEC and NFPA 
70E. [Ex. 3-8]

    OSHA agrees with Dow's rationale. The 2002 NEC and the 2000 and 
2004 editions of NFPA 70E recognize that it is safe to install power-
limited fire protective signaling circuits within 50.8 millimeters (2 
inches) of power conductors when there is an additional barrier between 
the two sets of conductors. Consequently, the Agency is adding the 
phrase "unless a special and equally protective method of conductor 
separation is employed," from existing Sec.  1910.308(d)(4) as 
highlighted in Dow's comments, to final Sec.  1910.308(d)(3)(iii) to 
permit additional means of protecting fire protective signaling circuit 
conductors from contact with conductors of other circuits. The final 
rule, with the revision emphasized, reads as follows:

    Power-limited fire alarm circuit conductors shall be separated 
at least 50.8 mm (2 in.) from conductors of any electric light, 
power, Class 1, nonpower-limited fire alarm, or medium power 
network-powered broadband communications circuits unless a special 
and equally protective method of conductor separation is employed.

P. Definitions

    The definitions for Subpart S are located in Sec.  1910.399. The 
changes to these definitions from the existing standard reflect the 
provisions of the 2002 NEC and NFPA 70E-2000. Table 4 (located at the 
end of section I. P. of the preamble) summarizes the changes to the 
definitions.
    OSHA is removing several definitions from the standard. "Special 
permission," "permanently installed swimming pools, wading and 
therapeutic pools," and "storable swimming and wading pools" are 
removed because these terms are not used in final Subpart S. Lastly, 
the definitions of "electric sign" and "may" are removed. The 
existing Subpart S definitions of these terms are not substantially 
different from the commonly accepted dictionary definitions. The 
definition of "electric sign" may appear different from the 
dictionary definition; however, the information in the existing 
definition adds nothing substantive within the context of the standard. 
Thus, their removal does not change the meaning of the standard.
    The final rule redefines the term "identified." The existing 
definition of "identified" applies to the use of this term in 
reference to a conductor or its terminal. The final rule discontinues 
the current standard's use of the word "identified" in this manner. 
The final rule does, however, define "identified" to refer to 
equipment suitable for a specific purpose, function, use, environment, 
or application.
    OSHA is also removing the definition of "utilization 
systems.\44\" This term is only used in existing Sec.  1910.301(a), 
which describes the content of Sec. Sec.  1910.302 through 1910.308, 
and in the title and introductory text of existing Sec.  1910.302. 
Existing Sec.  1910.301(a) reads as follows:
---------------------------------------------------------------------------

    \44\ In the proposed rule, OSHA listed the removal of this 
definition in the preamble in a table listing the summary of changes 
to the definitions. However, OSHA neglected to include the removal 
of this definition in the proposed regulatory text.

    Design safety standards for electrical systems. These 
regulations are contained in Sec. Sec.  1910.302 through 1910.330. 
Sections 1910.302 through 1910.308 contain design safety standards 
for electric utilization systems. Included in this category are all 
electric equipment and installations used to provide electric power 
and light for employee workplaces. Sections 1910.309 through 
1910.330 are reserved for possible future design safety standards 
---------------------------------------------------------------------------
for other electrical systems.

    The introductory text of Sec.  1910.302 reads as follows:

    Sections 1910.302 through 1910.308 contain design safety 
standards for electric utilization systems.

    These two provisions are intended as introductory text providing a 
general discussion of the contents of the standard. The precise scope 
of Sec. Sec.  1910.302 through 1910.308 is presented in final Sec.  
1910.302(a). However, OSHA is concerned that some employers and 
employees could incorrectly interpret the use of the term "utilization 
systems" and its definition as narrowing the scope of Sec. Sec.  
1910.303 through 1910.308. The term "utilization system" in the 
introduction to Subpart S is intended as a shorthand way of referring 
to the systems covered by Subpart S generally and Sec. Sec.  1910.303 
through 1910.308 specifically. Removing the definition from the 
standard should clarify that the language used in the introduction to 
Subpart S is not intended to alter the scope of Sec. Sec.  1910.302 
through 1910.308, as given in Sec.  1910.302(a).
    OSHA is adding 13 definitions to Sec.  1910.399. (See Table 4.) 
These definitions, all but one of which are based on NFPA 70E-2000 and 
the 2002 NEC, will help clarify the requirements in Subpart S. Other 
modifications made to the definitions are grammatical in nature, and no 
substantive change is being made in the meaning of the terms.
    A few terms warrant additional explanation: "Identified," 
"labeled," and "listed." The existing standard requires certain 
electric equipment to be "approved for the purpose," and current 
Sec.  1910.399 defines this term as follows:

    Approved for a specific purpose, environment, or application 
described in a particular standard requirement.
    Suitability of equipment or materials for a specific purpose, 
environment or application may be determined by a nationally 
recognized testing laboratory, inspection agency or other 
organization concerned with product evaluation as part of its 
listing and labeling program. (See "Labeled" or "Listed.")
    In the final rule, OSHA is replacing the word "approved" in the 
phrase "approved for the purpose," with "identified." The final 
rule's definition of "identified," which is based on the definition 
of this term in NFPA 70E-2000,\45\ reads as follows:
---------------------------------------------------------------------------

    \45\ Except for the note to the definition, the exact language 
was taken from the 2002 NEC. This version is clearer than the 
definition in NFPA 70E, but the intent is the same. OSHA has 
clarified the note to indicate that acceptability of testing and 
inspection agencies is given in the definition of "acceptable."

    Identified (as applied to equipment). Approved as suitable for 
the specific purpose, function, use, environment, application, and 
so forth, where described in a particular requirement.
    Note to the definition of "identified:" Some examples of ways 
to determine suitability of equipment for a specific purpose, 
environment, or application include investigations by a nationally 
recognized testing laboratory (through listing and labeling), 
inspection agency, or other organization recognized under the 
definition of "acceptable."

    The definition of "identified" as it applies to equipment is 
intended to be equivalent to the existing definition of "approved for 
the purpose." \46\
---------------------------------------------------------------------------

    \46\ NFPA 70E-2000 uses the word "recognizable" in lieu of 
"approved" in the definition of "identified." It also contains a 
fine print note following the definition indicating that suitability 
of equipment for a specific purpose, environment, or application may 
be determined by a qualified testing laboratory, inspection agency, 
or other organization concerned with product evaluation. The revised 
and existing OSHA standards both require all electric equipment to 
be approved, and this approval is the only mechanism for recognizing 
equipment as suitable. The Agency believes that the proposed 
definition of "identified" as applied to equipment clarifies the 
intent of the standard and is consistent with the existing 
standard's provisions that require electric equipment to be 
"approved for the purpose."
---------------------------------------------------------------------------

    In the final rule, OSHA uses the terms "listed" and "labeled" 
to refer to electric equipment determined to be safe by a nationally 
recognized testing laboratory (NRTL). When equipment has been listed 
and labeled, this means that the equipment has been tested and found 
safe for use by a nationally recognized testing laboratory. The 
laboratory marks the equipment with a symbol identifying its trademark. 
The equipment is then considered by OSHA to be safe for its intended 
use. If the equipment is altered or used for other purposes, then the 
equipment is not acceptable under Subpart S. The laboratories typically 
require the equipment to be marked with such information as: The 
standards under which the equipment has been tested; the current rating 
in amperes; and the frequency. OSHA evaluates and recognizes 
"nationally recognized testing laboratories" under Sec.  1910.7 to 
test equipment for safety and label or list it. It should be noted that 
the final rule would continue the existing Sec.  1910.399 definitions 
of "labeled" and "listed" without substantive change.
    The Dow Chemical Company recommended that OSHA supplement the 
proposed definition of "identified" with language from Section 
500.8(A)(1) of the 2002 NEC so that the definition would read as 
follows:
    Suitability of identified equipment for the purpose shall be 
determined by any of the following:
    (1) Equipment listing or labeling;
    (2) Evidence of equipment evaluation from a qualified testing 
laboratory or inspection agency concerned with product evaluation; or
    (3) Evidence acceptable to the authority having jurisdiction, such 
as a manufacturer's self-evaluation or an owner's engineering judgment. 
[Ex. 3-8]
    Dow Chemical believes that this language would provide flexibility 
to the employer when the equipment is not approved by a nationally 
recognized testing laboratory.
    As noted earlier, Sec.  1910.303(a) requires electric equipment to 
be approved, and the definitions of "approved" and "acceptable" set 
out what types of equipment OSHA will accept in enforcing Subpart 
S.\47\ Dow's suggestion does not clarify these definitions. Instead, it 
seems to imply equivalence between the three listed options. In 
comparison, OSHA's existing definition of "acceptable" clearly 
indicates a preference for listing, labeling, or other approval by a 
nationally recognized testing laboratory. At the same time, OSHA's 
existing definitions provide flexibility for employers when equipment 
is of a type that no nationally recognized testing laboratory 
evaluates. OSHA believes that the proposed definitions of 
"identified," "approved," and "acceptable" are clear and provide 
sufficient flexibility to employers. Therefore, the Agency is carrying 
them forward into the final rule without change.
---------------------------------------------------------------------------

    \47\ OSHA proposed no substantive changes to the definitions of 
"approved" or "acceptable" or to the requirement in existing 
Sec.  1910.303(a) that electric equipment be approved.
---------------------------------------------------------------------------

    The proposed definition of "acceptable" reads as follows:

    An installation or equipment is acceptable to the Assistant 
Secretary of Labor, and approved within the meaning of this Subpart 
S:
    (1) If it is accepted, or certified, or listed, or labeled, or 
otherwise determined to be safe by a nationally recognized testing 
laboratory recognized pursuant to Sec.  1910.7; or
    (2) With respect to an installation or equipment of a kind that 
no nationally recognized testing laboratory accepts, certifies, 
lists, labels, or determines to be safe, if it is inspected or 
tested by another Federal agency, or by a State, municipal, or other 
local authority responsible for enforcing occupational safety 
provisions of the National Electrical Code, and found in compliance 
with the provisions of the National Electrical Code as applied in 
this subpart; or
    (3) With respect to custom-made equipment or related 
installations that are designed, fabricated for, and intended for 
use by a particular customer, if it is determined to be safe for its 
intended use by its manufacturer on the basis of test data which the 
employer keeps and makes available for inspection to the Assistant 
Secretary and his authorized representatives.

    Mr. Ron Nickson, representing the National Multi Housing Council 
and the National Apartment Association, recommended that OSHA add the 
International Code Council Electrical Code (ICCEC), which is published 
by the International Code Council (ICC), to the second alternative in 
the definition of "acceptable" (Ex. 4-20). They believe that OSHA 
should accept evaluations made by local authorities enforcing the ICCEC 
as being equivalent to those made by authorities enforcing the NEC. In 
support of their position, they stated:

    The provisions in the ICCEC were developed during the ICC code 
development process to address and/or expand on issues not covered 
in the NEC. The ICC codes, including the ICCEC, are the result of 
more than 90 years of code enforcement by local building and fire 
officials. The ICCEC responds to issues that have come up during the 
inspection and approval process or have been brought to the 
attention of the ICC by participants in the ICC code development 
process. They have been reviewed by ICC Code development committees 
and voted into the code by the building and fire official members of 
ICC. They form an important part of the electrical installation and 
inspection process to insure that electrical work is installed in a 
safe manner to limit the possibility of injury to workers and others 
involved in the construction process. [Ex. 4-20]

    The commenter acknowledged that there are differences between the 
NEC and the ICCEC. However, there is little information in Mr. 
Nickson's submission or elsewhere in the rulemaking record that would 
enable OSHA to judge whether an evaluation of an electrical 
installation made under the ICCEC would be equivalent to one made under 
the NEC. In addition, Mr. Nickson does not present any evidence of how 
many jurisdictions, if any at all, enforce the ICCEC. Consequently, the 
Agency has decided against adding the International Code Council 
Electrical Code to the definition of "acceptable."
However, if in enforcing Subpart S the Agency determines that the 
underlying electrical standard, such as the ICCEC, being used by a 
particular local authority is based on the NEC, then OSHA will consider 
accepting that authority's determinations of electrical installation 
safety under the second alternative given in the definition of 
"acceptable."
    OSHA received several comments suggesting the addition of a 
definition of "fountain" to clarify the use of this word in proposed 
Sec.  1910.306(j)(5) (Exs. 4-13, 4-15, 4-18, 4-21). Typifying these 
comments, Mr. Michael Kovacic argued that the term "fountains" has 
been the source of considerable confusion and misinterpretation for 
many years. He stated that, although some apply the requirements on 
fountains in existing Sec.  1910.306(j)(5) to drinking fountains and 
water coolers, the NEC does not intend to apply the requirements on 
fountains to drinking fountains. To support his assertion, he pointed 
to 2002 NEC Section 680.2, which states that the definition of 
"fountains" does not include drinking fountains. The commenters 
recommend that OSHA either add the NEC definition of "fountains" to 
Sec.  1910.399 or otherwise clarify the application of Sec.  
1910.306(j)(5).
    OSHA agrees with these commenters and has included the 2002 NEC 
definition of "fountains" in final Sec.  1910.399.
    The Agency has also retained the proposed definitions of 
"permanently installed swimming pools, wading and therapeutic pools" 
and "storable swimming or wading pool." The preamble indicated that 
the definitions of these terms were to be removed because the terms 
were not used in the proposed standard. However, the proposal did 
include definitions of these terms in the regulatory text. The 
introductory text to final Sec.  1910.306(j) reads, in part, as 
follows:

    This paragraph applies to electric wiring for and equipment in 
or adjacent to all swimming, wading, therapeutic, and decorative 
pools and fountains; hydro-massage bathtubs, whether permanently 
installed or storable; and metallic auxiliary equipment, such as 
pumps, filters, and similar equipment. [Emphasis added.]

    OSHA believes that defining the terms "permanently installed 
swimming pools, wading and therapeutic pools" and "storable swimming 
or wading pool" will clarify the intent of final Sec.  1910.306(j). 
Even though the terms are not used precisely in the form used in the 
definitions, it is clear from the regulatory text that those two terms 
are what OSHA intends by the language in final Sec.  1910.306(j).
    Proposed Sec.  1910.308(c)(1) contained requirements governing the 
marking and limitations on power of Class 1, 2, and 3 remote control, 
signaling, and power-limited circuits. Some commenters recommended 
clarifying the standard by moving those provisions to Sec.  1910.399 or 
by including a cross-reference to Sec.  1910.308(c)(1) within the 
definition section.
    Paragraph (c)(1) of final Sec.  1910.308 sets mandatory limits on 
the power output for remote control, signaling, and power-limited 
circuits and sets requirements for marking the source of power for 
these circuits. These provisions are requirements, not definitions. 
Consequently, the Agency does not believe that it is appropriate to 
move them to or refer to them in the definition section.
    Some commenters identified definitions in the proposed rule that 
were inconsistent with the definitions in the NFPA 70E-2004 (Exs. 4-11, 
4-19). They identified as examples: "Armored cable" and "live 
parts." \48\ The commenters recommended that the definitions in Sec.  
1910.399 be consistent with NFPA 70E and the NEC.
---------------------------------------------------------------------------

    \48\ These commenters also identified the definition of 
"qualified person" as being inconsistent with the NEC definition. 
This comment is addressed later in this section of the preamble.
---------------------------------------------------------------------------

    In comparing the proposed definition of "live parts" with the one 
in the 2002 NEC (on which NFPA 70E-2004 is based), OSHA has found that 
the definition in its proposal is only slightly different from that of 
NFPA.\49\ The intent of OSHA's definition and the NEC definition is 
identical. To promote consistency with the NEC and NFPA 70E, the Agency 
has decided to adopt the 2002 NEC language for this definition in the 
final OSHA rule.
---------------------------------------------------------------------------

    \49\ The NEC definition of "live parts" is "energized 
conductive componenets." OSHA's proposed definition was 
"[E]lectric conductors, buses, terminals, or components that are 
energized." Since the word "components" includes conductors, 
buses, and terminals, there is no substantive difference between the 
two definitions.
---------------------------------------------------------------------------

    The definition of "armored (Type AC) cable" in the proposal is 
identical to the one in the 2002 NEC, though OSHA's proposed definition 
is worded as a complete sentence. The Agency has reworded the 
definition in the final rule (along with similarly worded definitions 
\50\) so that the format matches the other definitions in the final 
rule and the NEC.
---------------------------------------------------------------------------

    \50\ The following definitions were similarly worded in the 
proposed rule: "Medium voltage cable," "metal-clad cable," 
"mineral-insulated metal-sheathed cable," "nonmetallic-sheathed 
cable," "power and control tray cable," "power-limited tray 
cable," "service-entrance cable," "shielded nonmetallic-sheathed 
cable," and "wireways."
---------------------------------------------------------------------------

    In addition, the Agency has identified two additional definitions 
that could be clarified with the use of the corresponding 2002 NEC 
definitions: "Health care facilities" and "mineral-insulated, metal 
sheathed cable."
    The existing and proposed definitions of "health care facilities" 
read as follows:

    Buildings or portions of buildings and mobile homes that 
contain, but are not limited to, hospitals, nursing homes, extended 
care facilities, clinics, and medical and dental offices, whether 
fixed or mobile.

    This is not a true definition. Rather, it provides examples of 
health care facilities. The 2002 NEC definition of this term, in Sec.  
517.2, reads as follows:

    Buildings or portions of buildings in which medical, dental, 
psychiatric, nursing, obstetrical, or surgical care are provided. 
Health care facilities include, but are not limited to, hospitals, 
nursing homes, limited care facilities, clinics, medical and dental 
offices, and ambulatory care centers, whether permanent or moveable.

    OSHA believes that this language will clarify how that term is used 
and has adopted the NEC definition in the final rule.
    The proposed definition of "mineral-insulated, metal sheathed 
cable" stated that this was a type of cable with a "continuous copper 
sheath." The 2002 NEC states that the sheath may be of alloy steel in 
addition to copper. For consistency with the 2002 NEC, OSHA has revised 
the term "continuous copper sheath" from the definition in the 
proposal to "continuous copper or alloy steel sheath" in the final 
rule. This will ensure that the OSHA standard recognizes all the 
different types of approved mineral-insulated, metal sheathed cables 
currently available.
    The proposed definition of "qualified person" read as follows:

    A person who is familiar with the construction and operation of 
the equipment and the hazards involved. [Notes omitted.]

    OSHA received several comments on this definition (Exs. 4-11, 4-13, 
4-15, 4-18, 4-19, 4-21). These commenters recommended that OSHA use the 
corresponding definition from the 2002 NEC, which reads:

    One who has the skills and knowledge related to the construction 
and operation of the electrical equipment and installations and has 
received safety training on the hazards involved.

    Some of these commenters asserted that there is confusion in the 
electrical safety industry over the use of this term (Exs. 4-13, 4-15, 
4-18, 4-21). They also recommended including a note regarding the type 
of training needed before an employee could meet the definition.
    Paragraph (b)(3) of existing Sec.  1910.332 set specific training 
requirements that an employee must have to be considered a "qualified 
person." In fact, the first note to the proposed definition of 
"qualified person" pointed to that training requirement. Although the 
suggested definition is consistent with the training provisions, it 
does not demand that the person have the knowledge and skills related 
to the hazards posed by electrical installations that are to be 
imparted by the training. To capture the commenters' intent and retain 
the proposed definition's emphasis on acquired knowledge, the Agency is 
adopting the following definition of "qualified person:"

    One who has received training in and has demonstrated skills and 
knowledge in the construction and operation of electric equipment 
and installations and the hazards involved.

    The final rule also carries forward, unchanged, the two notes to 
the proposed definition.

             Table 4.--Summary of Changes to the Definitions
------------------------------------------------------------------------
        Old definition            New definition         Rationale
------------------------------------------------------------------------
                                Barrier..........  OSHA is adding this
                                                    definition to Sec.
                                                    1910.399 from NFPA
                                                    70E-2000.
                                Bathroom.........  OSHA is adding this
                                                    definition to Sec.
                                                    1910.399 from NFPA
                                                    70E-2000.
                                Class I, Zone 0..  OSHA is adding this
                                                    definition to Sec.
                                                    1910.399 from NFPA
                                                    70E-2000 to support
                                                    the new section on
                                                    Zone Classification
                                                    in Sec.   1910.307.
                                Class I, Zone 1..  OSHA is adding this
                                                    definition to Sec.
                                                    1910.399 from NFPA
                                                    70E-2000 to support
                                                    the new section on
                                                    Zone Classification
                                                    in Sec.   1910.307.
                                Class I, Zone 2..  OSHA is adding this
                                                    definition to Sec.
                                                    1910.399 from NFPA
                                                    70E-2000 to support
                                                    the new section on
                                                    Zone Classification
                                                    in Sec.   1910.307.
                                Competent person.  OSHA is adding this
                                                    definition to Sec.
                                                    1910.399 from Sec.
                                                    1926.32. See
                                                    discussion earlier
                                                    in the preamble.
Electric sign.................  [Removed]........  No substantive
                                                    change. See the
                                                    detailed explanation
                                                    earlier in this
                                                    section of the
                                                    preamble.
                                Energized........  OSHA is adding this
                                                    definition to Sec.
                                                    1910.399 from NFPA
                                                    70E-2000.
                                Fountain.........  OSHA is adding this
                                                    definition to Sec.
                                                    1910.399 from NEC-
                                                    2002. See the
                                                    detailed explanation
                                                    earlier in this
                                                    section of the
                                                    preamble.
Health care facilities........  Health care        OSHA is removing the
                                 facilities.        old definition and
                                                    adding the new
                                                    definition to Sec.
                                                    1910.399 from NEC-
                                                    2002. See the
                                                    detailed explanation
                                                    earlier in this
                                                    section of the
                                                    preamble.
Identified....................  Identified.......  This term is used in
                                                    a different manner
                                                    in the proposed
                                                    revision. The new
                                                    use and definition
                                                    are taken from NFPA
                                                    70E-2000. See the
                                                    detailed explanation
                                                    earlier in this
                                                    section of the
                                                    preamble.
                                Insulated........  OSHA is adding this
                                                    definition to Sec.
                                                    1910.399 from NFPA
                                                    70E-2000.
                                Live parts.......  OSHA is adding this
                                                    definition to Sec.
                                                    1910.399 from NEC-
                                                    2002.
May...........................  [Removed]........  No substantive
                                                    change. The
                                                    definition adds
                                                    nothing to the
                                                    dictionary
                                                    definition of this
                                                    term.
                                Motor Control      OSHA is adding this
                                 Center.            definition to Sec.
                                                    1910.399 from NFPA
                                                    70E-2000.
Nonmetallic-sheathed cable....  Nonmetallic-       OSHA is removing the
                                 sheathed cable.    old definition and
                                                    adding the new
                                                    definition to Sec.
                                                    1910.399 from NEC-
                                                    2002. See the
                                                    detailed explanation
                                                    earlier in this
                                                    section of the
                                                    preamble.
                                Overhaul.........  OSHA is using this
                                                    term in the standard
                                                    in place of "major
                                                    replacement,
                                                    modification,
                                                    repair, or
                                                    rehabilitation,"
                                                    which is used in the
                                                    existing standard to
                                                    delineate when an
                                                    electrical
                                                    installation must
                                                    meet new
                                                    requirements in the
                                                    standard. See the
                                                    explanation of the
                                                    definition and
                                                    related changes
                                                    under the summary
                                                    and explanation of
                                                    the grandfather
                                                    clause earlier in
                                                    this preamble.
Qualified person..............  Qualified person.  OSHA is revising this
                                                    definition. (See the
                                                    summary and
                                                    explanation of the
                                                    definition of
                                                    "qualified
                                                    person," earlier in
                                                    this section of the
                                                    preamble.)
                                Service point....  OSHA is adding this
                                                    definition to Sec.
                                                    1910.399 from NFPA
                                                    70E-2000.
Special permission............  [Removed]........  This term is not used
                                                    in Subpart S.
Utilization system............  [Removed]........  This definition is
                                                    being removed. See
                                                    the detailed
                                                    explanation earlier
                                                    in this section of
                                                    the preamble.
------------------------------------------------------------------------

 Q. Appendices

    Appendices B and C of the current Subpart S contain no material; 
they are reserved for future use. OSHA is removing these two "empty" 
appendices because the Agency has no material to include there.
    The existing Appendix A contains a list of references. OSHA is 
revising and updating the references in this appendix to reflect the 
most recent editions of various national consensus standards.\51\ These 
nonmandatory references can be used to assist employers who desire 
additional information that will help them to comply with the 
performance standard in Subpart S. In addition, OSHA is removing 
various reference standards from the appendix because the documents are 
no longer in print and because the information can be found in other 
listed sources. The following references are removed:
---------------------------------------------------------------------------

    \51\ The references in Appendix A in the final rule are to the 
latest revisions of the relevant documents, except for references to 
the NEC and NFPA 70E. For these two NFPA standards, OSHA has listed 
both the current versions (NFPA 70-2005 and 70E-2004) and the 
versions on which the final rule is based (NFPA 70-2002 and 70E-
2000). The Agency has reviewed these documents and found them to 
provide suitable guidance to assist employers in complying with the 
OSHA standards.

ANSI B9.1-71 Safety Code for Mechanical Refrigeration;
ANSI B30.15-73 Safety Code for Mobile Hydraulic Cranes;
ANSI C33.27-74 Safety Standard for Outlet Boxes Fittings for Use in 
Hazardous Locations, Class I, Groups A, B, C, and D, and Class II, 
Groups E, F, and G;
ASTM D2155-66 Test Method for Autoignition Temperature of Liquid 
Petroleum Products;
IEEE 463-77 Standard for Electrical Safety Practices in Electrolytic 
Cell Line Working Zones;
NFPA 56A-73 Standard for the Use of Inhalation Anesthetics (Flammable, 
Nonflammable);
NFPA 56F-74 Standard for Nonflammable Medical Gas Systems;
NFPA 70C-74 Hazardous Locations Classification;
NFPA 71-77 Standard for the Installation, Maintenance, and Use of 
Central Station Signaling Systems;
NFPA 72A-75 Standard for the Installation, Maintenance, and Use of 
Local Protective Signaling Systems for Watchman, Fire Alarm, and 
Supervisory Service;
NFPA 72B-75 Standard for the Installation, Maintenance, and Use of 
Auxiliary Protective Signaling Systems for Fire Alarms Service;
NFPA 72C-75 Standards for Installation, Maintenance, and Use of Remote 
Station Protective Signaling Systems;
NFPA 72D-75 Standard for the Installation, Maintenance and Use of 
Proprietary Protective Signaling Systems for Watchman, Fire Alarm, and 
Supervisory Service;
NFPA 72E-74 Standard for Automatic Fire Detectors;
NFPA 74-75 Standard for Installation, Maintenance, and Use of Household 
Fire Warning Equipment;
NFPA 76A-73 Standard for Essential Electrical Systems for Health Care 
Facilities;
NFPA 86A-73 Standard for Ovens and Furnaces; Design, Location and 
Equipment;
NFPA 88B-73 Standard for Repair Garages;
NFPA 325M-69 Fire-Hazard Properties of Flammable Liquids, Gases, and 
Volatile Solids; and
NFPA 493-75 Standard for Intrinsically Safe Apparatus for Use in Class 
I Hazardous Locations and Its Associated Apparatus.

    OSHA is adding five national consensus standards to the list.\52\ 
All but one of these documents refers to hazardous (classified) 
locations. The other document addresses articulating boom cranes. ANSI/
ASME B30.22-2005 Articulating Boom Cranes was not included in the 
proposal. However, the Agency has reviewed this standard and has found 
useful information comparable to the other ANSI/ASME standards for 
other types of cranes (for example, ANSI/ASME B30.5-2004 Mobile And 
Locomotive Cranes). Consequently, the following references are added:

    \52\ OSHA had proposed to add an additional national consensus 
standard to the list, ANSI/UL 2279-1997, Electrical Equipment for 
Use in Class I, Zone 0, 1 and 2 Hazardous (Classified) Locations. 
This standard is no longer active, because UL has added zone-related 
provisions to other of its standards on equipment for hazardous 
locations. Therefore, OSHA has not included this standard in 
Appendix A in the final rule.

ANSI/UL 913-2002 Intrinsically Safe Apparatus and Associated Apparatus 
for Use in Class I, II, and III, Division 1, Hazardous (Classified) 
Locations;
ANSI/API RP 500-1998 (2002) Recommended Practice for Classification of 
Locations for Electrical Installations at Petroleum Facilities 
Classified as Class I Division 1 and Division 2;
ANSI/API RP 505-1997 (2002) Recommended Practice for Classification of 
Locations for Electrical Installations at Petroleum Facilities 
Classified as Class I, Zone 0, Zone 1 and Zone 2;
ANSI/ASME B30.22-2005 Articulating Boom Cranes; and
NFPA 820-2003 Standard for Fire Protection in Wastewater Treatment and 
Collection Facilities.


    Comments to the appendices. OSHA received a comment to reference 
other national consensus standards in Appendix A, like ANSI Z490.1 and 
ANSI Z244.1, to help employers with new training requirements in 
electrical installations (Ex. 3-5). These voluntary consensus standards 
offer benefits in guiding employers on establishing appropriate 
training procedures for their employees. The national consensus 
standards listed in Appendix A are there to be used as a guideline to 
help employers with implementing the requirements for electrical 
installation and safe work practices and procedures in Subpart S. OSHA 
has reviewed both standards and has added them to the list of voluntary 
standards in the appendices.

R. Powered Platforms for Building Maintenance

    Mandatory Appendix D to Sec.  1910.66, powered platforms for 
building maintenance, applies to powered platforms installed between 
August 28, 1971, and July 23, 1990. Paragraphs (c)(22)(i) and 
(c)(22)(vii) in that appendix incorporate the 1971 NEC by reference. 
OSHA is referencing Subpart S instead. The final rule, which would 
replace the highly specification-oriented NEC with the performance-
oriented Subpart S, will make the standard more flexible for employers 
maintaining these platforms but will retain the protection currently 
afforded employees.\53\ In addition, employers will no longer need to 
refer to the NEC to determine how to comply with OSHA's standard for 
powered platforms. This change is deregulatory in nature and should not 
result in significant costs to employers.
---------------------------------------------------------------------------

    \53\ Employers who make minor modifications to these platforms 
would thus be required to follow Subpart S rather than the 1971 NEC. 
Newer installations and major modifications of older platforms are 
already required to meet Subpart S with respect to the platform's 
electrical wiring and equipment.
---------------------------------------------------------------------------

    OSHA received no comments in response to this proposed change. 
Consequently, it is being carried without change into the final rule.

VI. Final Economic and Regulatory Screening Analysis

A. Existing Versus Final Rule

    The final rule revises and updates the provisions contained in 
Sections 1910.302-1910.308 and 1910.399 of the existing Subpart S 
electrical installation standard. The original version of Subpart S, 
adopted under Sec.  6(a) of the OSH Act, incorporated the 1971 National 
Electrical Code (NEC) by reference. In 1981, OSHA replaced the 
incorporation by reference with updated provisions based on the 1979 
National Fire Protection Association (NFPA) 70E committee 
recommendations. The 1981 version relied on the 1978 NEC. The 
rulemaking will revise and update the OSHA electrical installation 
standard to be consistent with most of the NFPA 70E recommendations 
developed in 2000, which are based on the 1999 NEC, and to update 
requirements for new electrical installations.
    OSHA has conducted a detailed comparison of the existing and final 
rules in order to determine the extent to which the provisions of the 
final rule will increase compliance costs. Table 7 summarizes the 
changes associated with the provisions of the final rule that have cost 
implications. OSHA's comparative analysis indicates that the changes in 
the final rule fall into four categories: (1) Changes in hardware 
specifications that are consistent with NEC requirements; (2) changes 
in installation practices that are consistent with current, normal and 
customary installation practices routinely followed by licensed 
electricians; (3) clarifications of existing requirements that do not 
add additional obligations and/or allow greater flexibility for 
achieving compliance; and (4) requirements that may require
significant changes in electrical system and equipment installation 
practices.
    The first three categories of changes introduced by the final rule 
are not expected to result in any additional costs. Category 1 changes 
are not expected to increase costs because virtually all equipment 
manufacturers routinely follow current NEC requirements regarding 
hardware specifications. Category 2 changes are not expected to result 
in any increase in compliance costs since virtually all licensed 
electricians routinely follow NEC requirements for installing 
electrical systems and equipment. Category 3 changes do not add any new 
installation or work practice requirements, but simply restate or 
eliminate existing requirements.
    Regarding Category 4, a number of changes indicated by the final 
rule correspond to revisions to the NEC made prior to 1999. Because 
these changes have been in the NEC since the previous edition (1996), 
they are believed to represent widespread current industry practice. 
Therefore, these changes are not expected to result in increased 
compliance costs. Moreover, construction requirements usually imposed 
by mortgage lenders and insurance carriers, as well as installation 
practices routinely followed by licensed electricians (given their 
formal training), are generally consistent with the NEC requirements. 
In sum, there is a subset of Category 4 changes that can be assumed to 
be equivalent to the Category 2 changes described above. Only those 
Category 4 changes that represent additions or revisions in the 1999 
NEC (to the 1996 NEC) are expected to potentially result in any 
increase in compliance costs.
    As noted, many Category 4 changes are not expected to increase 
compliance costs. In order to avoid having employers incur the costs of 
retrofitting the existing electrical systems and equipment in their 
buildings and facilities, OSHA has identified (in Sec.  1910.302(b)(4)) 
the substantive new provisions in the final rule, and then excluded 
(grandfathered) all existing electrical systems and equipment 
installations from having to comply with these new requirements. These 
provisions will only apply to new installations (that is, electrical 
systems and equipment installed for the first time, as well as 
installations that represent a major replacement, modification, repair, 
or rehabilitation of an existing electrical system) made after the 
effective date of the standard. Of the new provisions identified in 
Sec.  1910.302(b)(4), there are 14 provisions (or sets of related 
provisions) in Category 4 that were added or last revised in the 1999 
NEC. A number of these provisions represent changes in design and/or 
operating practices. OSHA believes that with the appropriate lead time 
(that is, sufficient delay in the effective date of the final rule), 
these provisions should not result in any incremental costs because 
these requirements can be reviewed and considered, and the electrical 
installation practices altered as necessary, prior to any work being 
performed. For instance, the requirement in Sec.  1910.303(f)(4) for 
disconnecting means to be capable of being locked in the open position 
can be met through selecting appropriate equipment in the installation 
design phase of a project. The feature required by this provision is 
already available in new equipment. OSHA sees no appreciable difference 
in cost between a disconnecting means that is capable of being locked 
in the open position and one that is not. Other provisions, such as 
Sec.  1910.303(g)(1)(vii), which requires certain electric equipment to 
be installed in dedicated space, involve facility layout that can be 
met with no appreciable cost impact as long as the requirement is taken 
into consideration during the installation design phase of a 
project.\54\ The final rule provides employers with a 6-month delay in 
effective date, in part, so that they can incorporate such 
considerations during the design of new electrical installations. (See 
section XII, Effective Date and Date of Application, later in this 
preamble.)
---------------------------------------------------------------------------

    \54\ For example, a lighting fixture installed over a panelboard 
must be more than 1.83 m above the floor. It should not cost 
significantly more to install the fixture at such a height than it 
would to install it at a lower one.
---------------------------------------------------------------------------

    In addition to the provisions identified in Sec.  1910.302(b)(4), 
there are also new provisions identified in Sec.  1910.302(b)(2) and 
(b)(3) of the final rule that apply to: (1) Electrical system and 
equipment installations (either first time or major replacement, 
modification, repair, or rehabilitation) made after March 15, 1972; and 
(2) electrical system and equipment installations (either first time or 
major replacement, modification, repair, or rehabilitation) made after 
April 16, 1981, respectively. Reviewing the provisions identified in 
Sec.  1910.302(b)(2) and (b)(3) of the final rule, there are 13 new 
provisions (or sets of related provisions) in Category 4 that were 
added or last revised in the 1999 NEC. Table 7 also lists those 
provisions with cost implications. Again, a number of these 13 new 
provisions represent changes in design or operating practice rather 
than new equipment requirements, and as discussed earlier, are not 
expected to result in any incremental costs as long as there is 
sufficient delay in the effective date of the final rule.
    OSHA has examined other new provisions for possible cost impacts. 
First, Sec.  1910.302(b)(1) of the existing and final rule identifies 
those provisions (that is, specific sections in the standards) that all 
new and existing electrical system and equipment installations must 
meet regardless of the installation date. For these provisions in the 
existing and final rule, there is no grandfathering of older, existing 
electrical system and equipment installations. However, OSHA has 
concluded that Sec.  1910.302(b)(1) imposes no new, substantive 
Category 4 requirements for existing electrical systems and equipment 
installations. Further, while Sec.  1910.302(b)(1) does add new 
coverage from Sec.  1910.307, only documentation of hazardous locations 
is a totally new requirement, and the documentation for the division 
system only applies to installations made or overhauled after the 
effective date. The rest of the new provisions in Sec.  1910.307 allow 
employers to continue using the division system or to implement an 
alternative zone system for classifying hazardous locations containing 
flammable gases or vapors. They should not result in any additional 
costs unless employers voluntarily choose to abandon their present 
division system in favor of the alternative zone system. Finally, there 
are new provisions not contained in the existing OSHA electrical 
installation standard that were originally in the 1971 NEC and were 
enforced by OSHA between March 15, 1972, and April 16, 1981. The latest 
version of NFPA 70E reincorporated these provisions. (For a full 
explanation, see the discussion of final Sec.  1910.302(b)(2), in 
section V, Summary and Explanation of the Final Standard, earlier in 
the preamble.) OSHA believes that these provisions represent widespread 
current industry practices, because they have been part of every 
version of the NEC since 1971, including the 1999 and 2002 editions, 
and will not impose any additional cost.

B. Potentially Affected Establishments

    The electrical safety standard is based primarily upon the 2000 
NFPA 70E recommendations, which, in turn, are based on the 1999 NEC. 
Consequently, companies that are installing electrical systems and 
equipment in their facilities in locations where the 1999 (or 2002) NEC 
is currently being followed will not be further impacted by OSHA's 
rulemaking with respect to new installations. Further, given that there 
are no new, substantive Category 4 provisions in the rule that are 
mandatory for all existing electrical system and equipment installations 
(see above discussion), these provisions will not result in any economic 
impact for existing installations, until they are replaced, repaired, 
and/or renovated.
    In order to estimate the number of employers potentially impacted 
by the rulemaking, OSHA has identified the States and municipalities 
that currently mandate the 1999 (or 2002) National Electrical Code 
(NEC), that currently mandate using an earlier NEC, or that have no 
mandated statewide electrical code pertaining to new installations.\55\ 
These states were identified using information contained in the 
Directory of Building Codes and Regulations, by City and State 
(National Conference of States on Building Codes and Standards, NCSBCS, 
2002). In sum, 38 of the 50 States have already passed mandatory 
minimum building or fire codes specifying that new construction 
(including new electrical installations) must meet or exceed the 
requirements of the 1999 (or 2002) National Electrical Code (NEC).\56\ 
Thus, OSHA assumes that employers in the covered industries in all 
locations in these 38 States (except for Baltimore, MD) will be 
unaffected by OSHA's rulemaking with respect to new installations. 
These States (with the particular NEC indicated) are listed in Table 5:
---------------------------------------------------------------------------

    \55\ In States with no mandated electrical code pertaining to 
new installations, OSHA's existing standards, which are primarily 
based on the 1971 and 1978 NECs, are the governing rules. (In State 
Plan States, each State has adopted a standard that Federal OSHA has 
found to be at least as effective as the Federal standard. For all 
practical purposes, this means that OSHA's existing standard is the 
governing standard unless the State has adopted a more stringent 
standard.)
    \56\ Maryland has adopted the 1999 NEC as a Mandatory Minimum 
Code, exempting Baltimore from compliance. Generally when a state 
updates these mandatory minimum requirements, the new requirements 
apply only to new facilities or installations.

  Table 5.--States With Building or Fire Codes That Meet or Exceed the
                      1999 National Electrical Code
------------------------------------------------------------------------

-----------------------------------------------------------------------------
Alaska
Arkansas
California
Colorado
Connecticut
Delaware
Florida
Georgia
Idaho
Indiana
Kentucky
Maine
Maryland
Massachusetts
Michigan
Minnesota
Montana
Nebraska
New Hampshire
New Jersey
New Mexico
New York
North Carolina
North Dakota
Ohio
Oklahoma
Oregon
Pennsylvania
Rhode Island
South Carolina
South Dakota
Tennessee
Utah
Vermont
Washington
West Virginia
Wisconsin
Wyoming
------------------------------------------------------------------------

    Moreover, 16 large cities in other States have also adopted the 
1999 NEC. Therefore, employers in the covered industries in these 
municipalities are also expected to be unaffected by OSHA's rulemaking 
with respect to new installations. These cities are listed in Table 6:

  Table 6.--Cities That Have Adopted the 1999 National Electrical Code
------------------------------------------------------------------------

---------------------------------------------------------------------------
Austin, Texas
Chicago, Illinois
Dallas, Texas
Des Moines, Iowa
El Paso, Texas
Forth Worth, Texas
Honolulu, Hawaii
Houston, Texas
Jackson, Mississippi
Kansas City, Missouri
Las Vegas, Nevada
Phoenix, Arizona
San Antonio, Texas
St. Louis, Missouri
Tucson, Arizona
Wichita, Kansas
------------------------------------------------------------------------

    Further, the State of Alabama has adopted a limited mandatory 
minimum code, which, in effect, requires that hotels, schools, and 
movie theaters follow the 2002 NEC. Therefore, in this analysis, 
hotels, schools, and movie theaters in Alabama have been included with 
the group of 38 States and 16 large cities (described above) that 
currently follow the 1999 (or 2002) NEC.
    The remaining 12 States (or portions of these States) that would 
likely be affected by OSHA's rulemaking can be separated into two 
subgroups: (1) States or municipal jurisdictions that have adopted the 
1996 version of the NEC; and (2) States that have not adopted any 
statewide electrical code covering all non-government-owned buildings 
or facilities (that is, private sector installations). For group 1, to 
the extent that any of these jurisdictions adopt a later version of the 
NEC before this final rule goes into effect, annual compliance costs 
will likely be lower than estimated below.
    Five States and three cities fall into the first of the two 
subgroups described above. These include all locations in Louisiana and 
Virginia, as well as portions of Arizona, Iowa, and Nevada (that is, 
all locations in these three States excluding the four large cities in 
these States that have adopted the 1999 NEC, as indicated in the list 
above). The three large cities in the first subgroup include Baltimore, 
MD, Birmingham, AL (excluding hotels, schools, and movie theaters), and 
Washington, DC. Employers in these locations may be affected to the 
extent that the 1999 NEC, which is the basis for the rulemaking, 
differs from the 1996 NEC.
    Many of the new provisions in the final rule, including those in 
Category 4 that have potential cost implications for new electrical 
systems and equipment installations, date back to the 1996 NEC or to an 
NEC prior to 1996. Thus, for these provisions, employers in locations 
now requiring that the 1996 NEC be followed will not be affected by 
OSHA's rulemaking with respect to new installations.
    Seven States have not yet adopted any statewide electrical code 
that applies to all private sector employers. These States include: 
Alabama (excluding hotels, schools, and movie theaters), Hawaii, 
Illinois, Kansas, Mississippi, Missouri, and Texas. Employers in these 
States are expected to be the most affected (of the three subgroups) by 
OSHA's rulemaking, since no Statewide electrical code is currently 
required. For these seven States, OSHA's existing electrical 
installation standard, which is primarily based on the 1971 and 1978 
NECs, governs.\57\ Below the Statewide level, it is not clear to what 
extent local jurisdictions have passed local electrical ordinances that 
exceed the 1971 and 1978 NECs and are consistent with the 1999 NEC. 
While it is likely that some local jurisdictions within these 
states enforce the 1999 (or 2002) NEC, OSHA's analysis treats these 
States as though they are not in compliance with either the 1999 or 
2002 NEC for purposes of analysis. As a consequence, the estimated 
compliance costs are likely to be overstated.
---------------------------------------------------------------------------

    \57\ Note that of these seven States, Hawaii is the only State 
Plan State. Hawaii has adopted the Federal standard.
---------------------------------------------------------------------------

    Using data from the U.S. Department of Commerce's 1997 County 
Business Patterns database, OSHA has estimated the total number of 
affected establishments and employment in those establishments for the 
58 two-digit SICs covered by the general industry electrical safety 
installation standard.\58\ In addition, the number of establishments 
and employment that are already subject to the 1999 NEC, the 1996 NEC, 
the 1990 NEC, and no statewide electrical code, are also estimated. For 
those cities (identified above) that are currently following a 
particular electrical code, OSHA has estimated the number of 
establishments and employment in these cities using, as a surrogate, 
the data for the county in which the cities are located.
---------------------------------------------------------------------------

    \58\ These 58 SICs include employers in shipyard employment, 
longshoring, and marine terminals. Consistent with the preliminary 
analysis, OSHA in this final analysis has grouped affected 
industries according to the 1987 Standard Industrial Classification 
System. For industry coding under the North American Industry 
Classification System (NAICS), see NAICS, Executive Office of the 
President, Office of Management and Budget, 1997 and 2002, or http://www.census.gov/epcd/www/naics.html.

---------------------------------------------------------------------------

    The data indicate that there are an estimated 5.6 million 
establishments with 89.8 million employees in the industries covered by 
the general industry electrical safety installation standard. About 
84.7 percent of the establishments, employing about 85.3 percent of the 
employees, are in States or cities that have adopted the 1999 (or 2002) 
NEC. Approximately 6.3 percent of both the establishments and employees 
are in States or cities that have adopted the 1996 NEC. The remaining 
approximately 9.0 percent of the establishments, employing about 8.4 
percent of the employees, are in States (excluding certain cities in 
these States) that have not adopted a statewide electrical code 
applicable to private sector employers. Table 8 summarizes these 
findings.

C. Benefits

    Occupational fatalities associated with electrical accidents remain 
a significant and ongoing problem. The final rule would benefit 
employees by reducing their exposure to electrical hazards thereby 
reducing both fatal and nonfatal injuries.
    Table 9 presents data from the Survey of Occupational Injuries and 
Illnesses and the Census of Fatal Occupational Injuries on the number 
of work-related injuries and deaths in private industry attributed to 
contact with electrical current for 1992-2004. While the numbers of 
injuries and deaths appear to have declined, this decline has not been 
consistent throughout the time for which data are available. 
Electrical-related injuries increased between 1992 and 1994, then 
declined for 1995 to 1997. For 1998 and 1999, injuries again increased. 
Note that the percentage of occupational injuries associated with 
electrical hazards has remained essentially constant throughout 1992 to 
2004. The number of deaths associated with contact with electrical 
current declined in 1993, but rose during 1994 and 1995. Deaths dropped 
in 1996, but rose again in 1997 and 1998. As a percentage of total 
occupational fatalities, death due to electrocution appears to have 
remained constant or declined slightly. However, contact with 
electrical current remains a significant source of occupational 
fatality, accounting for 4.4 percent of total occupational fatalities 
in 2004.
    For more than 30 years, electrical hazards have been a target of 
OSHA rules. This rule will help to further reduce the number of deaths 
and injuries associated with electrical accidents, and ensure that a 
downward trend in these incidents is sustained.
    To determine the extent to which the standard may reduce the number 
of deaths attributable to electrical accidents, OSHA examined its 
accident investigation reports for the States without any statewide 
electrical code.\59\ The most recent and complete reports cover 1990-
1996, and provide detailed information on the cause of fatal electrical 
accidents. The accident cause can be used to ascertain whether the 
death would have been prevented by compliance with the final rule. As 
an initial screen, OSHA reviewed the reports for accidents that could 
have been prevented through the use of a GFCI. While OSHA expects that 
other provisions of the revised standard potentially will reduce deaths 
due to electrical accidents, this initial screen focused on GFCI-
related accidents since they are relatively easy to isolate using a key 
word search through all reports. Thus, the accident report analysis is 
conservative in the sense that it likely understates the number of 
deaths preventable under the revision to Subpart S.
---------------------------------------------------------------------------

    \59\ Some cities within these States have adopted the 1999 (or 
later) NEC, and these cities were excluded when examining the 
accident report data.
---------------------------------------------------------------------------

    OSHA found that there were at least nine deaths in the seven States 
that lacked a statewide electrical code during 1990-1996, or an average 
of 1.3 deaths per year that could have been prevented with the use of a 
GFCI. Based on EPA's estimate of a value of $6.1 million for a 
statistical life, the estimated 1.3 lives saved per year (that is, 
between 1 and 2 lives saved per year) under the final rule would 
translate to an annual benefit of $7.9 million (ranging from $6.1 
million to $12.2 million).\60\ As noted above, the monetized benefits 
understate total benefits since they do not cover all potentially 
preventable deaths. Moreover, they do not account for any preventable 
nonfatal injuries.
---------------------------------------------------------------------------

    \60\ See EPA's Guidelines for Preparing Economic Analyses, EPA 
240-R-00-003, September 2000. Note that the $6.1 million is in 1999 
dollars. If this figure is updated for inflation using the CPI as 
EPA indicates is appropriate, the estimated 1.3 lives saved per year 
(between 1 and 2 lives saved per year) would translate to an annual 
benefit of $9.4 million (between $7.2 million and $14.4 million) in 
2005 dollars.
---------------------------------------------------------------------------

    In addition to quantifiable potential benefits, this update to 
OSHA's electrical standards yields important unquantified benefits. The 
revised standard potentially reduces industry confusion and 
inefficiency associated with the current standard, which is out of date 
with today's technology. While OSHA has a long-standing policy of 
permitting employers to comply with more current versions of national 
consensus standards to the extent the more current version is as 
protective as the older version, this does not address all the concerns 
with the outdated standard. The older electrical standards may not 
address the hazards associated with newer equipment and machinery, 
leaving employers unsure which requirements presently apply. For 
example, the final standard contains requirements for electric 
equipment installed in hazardous locations classified under the zone 
classification system, which is not addressed in the existing standard. 
(See the summary and explanation of zone classification in section N. 
earlier in the preamble.) The update to Subpart S will reduce or 
eliminate these problems.

D. Estimation of Compliance Costs

    OSHA adopted a conservative approach to estimating compliance 
costs, and consequently, the estimates reported below are likely to 
overstate actual compliance costs. In summary, OSHA did not estimate 
any cost savings associated with the final rule, even though many new, 
potentially less costly alternative compliance methods are incorporated 
in the final rule. For example, as noted above, the rule will permit 
electric equipment in Class I hazardous locations to be installed under 
the zone classification system, which is not addressed in the existing 
standard. Because the hazardous locations provision potentially reduces 
industry confusion and inefficiency associated with the current standard, 
costs savings are likely.
    For all provisions with the exception of Sec.  1910.304(b)(3)(ii) 
(GFCI protection for temporary wiring installations), cost estimates 
were developed on a project-level basis. This involved obtaining data 
on the number of construction and other major renovation, addition, and 
alteration projects performed annually in States and local 
jurisdictions that do not now mandate the 1999 NEC (or equivalent).\61\ 
Table 10 summarizes the data on the number of projects potentially 
impacted by the final rule. In States and local jurisdictions that do 
not now mandate the 1999 NEC (or equivalent), the data indicate that 
there were a total of 29,306 project starts in 2001, consisting 
primarily (91 percent) of small projects under $3 million. Less than 
0.5 percent of the projects were large projects over $25 million.
---------------------------------------------------------------------------

    \61\ Data on new and other (major renovation, addition, and 
alteration) construction projects started annually between 1998 and 
2001 are compiled by F.W. Dodge (Schriver, 2002). While construction 
projects serve as the basis for estimating costs, construction is 
not covered by the final standard. Rather, it is the particular 
product or output of the construction project that is covered.
---------------------------------------------------------------------------

    For Sec.  1910.304(b)(3)(ii), compliance costs were estimated on an 
establishment-level rather than project-level basis. OSHA estimates 
that approximately 861,400 establishments are in locations that either 
are currently following the 1996 NEC or have not adopted a statewide 
electrical code applicable to private sector employers. These employers 
potentially are impacted by the final rule. Costs per provision were 
computed according to establishment size: establishments with fewer 
than 100 employees, establishments with 100-499 employees, and 
establishments with 500 or more employees.
    All potentially impacted projects/establishments would not 
necessarily be affected by each and every provision, and some would not 
be affected at all in any given year. Thus, it was necessary to 
estimate the percentage of projects/establishments affected by each 
provision annually. This percentage, when multiplied by the number of 
potentially impacted projects/establishments yields the number of 
projects/establishments subject to each provision annually without 
considering baseline levels of compliance. Table 11 presents the 
estimated percentage of projects/establishments that actually would be 
affected by each provision annually. These estimates were based on 
experience and technical knowledge of electrical practices.
    Baseline levels of compliance associated with each of the new 
provisions also were considered. Baseline levels of compliance were 
estimated for each provision by considering construction requirements 
imposed by mortgage lenders and insurance carriers and installation 
practices routinely followed by licensed electricians (given their 
formal training). (See the earlier discussion of categories of changes 
in the final rule.) These requirements and installation practices are 
generally consistent with the current NEC requirements. Moreover, it is 
expected that these requirements and practices generally become more 
prevalent as the size of the establishment or project increases. Table 
12 presents the estimated percentages for baseline compliance rates. 
These estimates were based on experience and technical knowledge of 
electrical practices.
    For each provision, estimates of labor and material costs were 
developed on a project level basis. Labor costs are based on an hourly 
wage rate of $20.44 for an electrician in the construction sector (SICs 
15-17 (NAICS 236-238)) to perform the work (plus fringe benefits at 37 
percent).\62\ Costs for materials, which consist of labels, GFCIs, 
conduits, connectors, and outlets, are based on data in the Maintenance 
Direct Catalog of Lab Supply, Inc. (2001). Equipment costs were 
annualized assuming the useful life of the equipment is two years and 
an interest rate of 7 percent. Table 13 summarizes the key data and 
bases for the cost estimates.
---------------------------------------------------------------------------

    \62\ The wage rate data are for 2000, taken from the BLS (2001) 
2000 National Occupational Employment Statistics (OES) Survey. 
Fringe benefit rate data are from BLS (2000) Employer Costs for 
Employee Compensation, March. USDL: 00-186.
---------------------------------------------------------------------------

    OSHA received very few comments on the preliminary economic and 
regulatory flexibility screening analysis.
    The National Petrochemical and Refiners Association (NPRA) stated 
in Ex. 3-2 that "the cost merely to read and comprehend the ruling, 
and to train personnel, will be at least in the tens of thousands of 
dollars per facility." However, NPRA provided no material to 
substantiate this claim. OSHA believes that the final rule imposes no 
cost to comprehend or to train personnel, particularly given the 
widespread use of the 1999 and 2000 NEC.
    CHS, Inc. stated, "the proposed rule could result in several unit 
start-ups/shutdowns at farmer-owned petroleum refineries" (Ex. 4-25). 
However, CHS did not explain how the new provisions in this standard 
would require additional outages to deenergize beyond those which could 
develop from compliance with the existing standard.
    Although OSHA received no new data in response to the preliminary 
analysis, OSHA has slightly revised its economic model in order to make 
it more realistic and to reflect changes between the proposed and final 
regulatory text. For example, in assigning compliance costs to Sec.  
1910.304(b)(3), Ground-fault circuit interrupter protection for 
personnel, OSHA's final model predicts that a small percentage of 
projects will establish and implement an assured grounding conductor 
program where ground-fault circuit interrupter protection is not 
available. An example of a revision to the preliminary analysis that 
reflects real-world considerations is the addition in the final 
analysis of an explicit cost for legible marking of equipment to 
indicate that the equipment has been applied with a series combination 
rating, as required by Sec.  1910.303(f)(5), Marking for series 
combination ratings.
    In addition, the final rule contains some new provisions that were 
not in the proposed rule or that were revised from what was in the 
proposal. Three of those provisions potentially require modification of 
existing installations: (1) Final Sec.  1910.304(a)(3), which prohibits 
a grounding terminal or grounding-type device on a receptacle, cord 
connector, or attachment plug from being used for purposes other than 
grounding, (2) final Sec.  1910.304(g)(4)(iii), which no longer permits 
extensions of branch circuits to be grounded by connection to a 
grounded cold water pipe, and (3) final Sec.  1910.304(g)(8)(iii), 
which no longer permits electric equipment to be grounded only by 
connection to the grounded structural metal frame of a building when 
any element of the equipment's branch circuit is replaced.
    A prohibition against using grounding terminals and grounding-type 
devices for purposes other than grounding is already contained in 
existing Sec.  1910.304(a)(3). Under the current standard, this 
provision applies to all electrical installations including major 
replacements, modifications, repairs, or rehabilitations made after 
March 15, 1972. In the final rule, OSHA is extending the application of 
this prohibition to installations made before that date. Wiring a 
receptacle, cord connector, or attachment plug so that the grounding 
terminal or other grounding-type device is used for purposes other than 
grounding (for example, by connecting a circuit conductor to the grounding 
terminal) makes the electric equipment extremely unsafe, posing an immediate 
threat of electrocution. In addition, such an incorrect wiring 
connection renders the equipment unusable, and it would likely have 
already been changed. Consequently, it is extremely unlikely that 
violations of this rule exist in significant numbers, and OSHA has 
concluded that applying this provision to all existing installations 
will have little if any economic impact.
    Existing Sec.  1910.304(f)(3)(iii) permits connecting the equipment 
grounding terminal of grounding-type receptacles to a nearby grounded 
cold water pipe for extensions of existing branch circuits that do not 
have an equipment grounding conductor. In the final rule, OSHA is 
requiring that, when any element of this branch circuit is replaced, 
the entire circuit include an equipment grounding conductor that 
complies with all other provisions of paragraph (g) of Sec.  
1910.304.\63\ This change only affects a small percentage of branch 
circuits extended after March 15, 1972, the date the provision went 
into effect. The existing requirement makes the equipment grounding 
path dependent upon the metallic continuity of the cold water piping 
and upon the earth for the electric current's return path back to the 
electric source. If a ground fault occurs at electric utilization 
equipment (for example, a portable cord-connected electric drill with a 
grounding-type attachment plug) plugged into a grounding-type 
receptacle and if the continuity of the water pipe is interrupted by a 
section plastic pipe or by another means, the electric equipment 
becomes extremely lethal, posing an immediate threat of electrocution. 
Additionally, the practice of using metallic water pipes as an 
equipment grounding conductor poses an electrocution hazard to 
plumbers, pipe fitters, and other employees working on the system who 
might unknowingly interrupt a path of fault current flowing through the 
piping. The return current path in both instances is through the 
employee instead of through a reliable equipment grounding conductor. 
Employers have become aware that using cold water plumbing for 
grounding is a poor practice and most have already corrected this 
condition, which is a violation of recent editions of the NEC \64\. 
According to Karl M. Cunningham of Alcoa (Ex. 4-4), the permission to 
use a cold water pipe near the equipment was clearly removed from the 
NEC for many Code cycles, including the 2002, 1999, 1996, and 1993 
editions.
---------------------------------------------------------------------------

    \63\ For example, 1910.304(g)(4)(iii) requires that when any 
element of a branch circuit extension is replaced, the entire branch 
circuit shall include an equipment grounding conductor.
    \64\ For example, a metallic cold water pipe is not listed in 
Section 250.118 of the 2002 NEC as a type of equipment grounding 
conductor.
---------------------------------------------------------------------------

    Because the NEC has not allowed this practice for over 10 years, 
few employers use this provision in the existing rule due to the known 
hazards. Therefore, it is unlikely that violations of this rule exist 
in significant numbers. Even then, employers who are still using cold 
water piping to ground branch-circuit extensions are only required to 
upgrade them when they are replacing one of the branch circuit 
extension's elements. The installation of the equipment grounding 
conductors would be coincidental with the modification work; and, thus 
the cost of compliance would be incidental. Hence, OSHA has concluded 
that requiring this provision for all modifications made to existing 
installations will impose no appreciable costs on employers.
    A prohibition against maintaining the grounded structural metal 
framing of a building for purposes of grounding electric equipment is 
contained in existing Sec.  1910.304(f)(6)(ii). This provision 
currently applies only to installations made after April 16, 1981. In 
the final rule, Sec.  1910.304(g)(8)(iii), OSHA is also applying this 
prohibition to installations made or designed before April 16, 1981, 
when any element of the equipment's branch circuit is replaced.
    Metal frames of buildings provide a poor substitute for an 
equipment grounding conductor. Installations that might have initially 
provided a permanent, continuous, and effective equipment grounding 
path fail to function adequately as time passes. If a fault occurs in 
the electric equipment an extremely lethal condition exists, posing an 
immediate threat of electrocution, since the return current path is 
through the employee instead of the intended equipment grounding path. 
As brought forth by one commenter (Ex. 4-18) and stated in the preamble 
discussion for proposed Sec.  1910.304(g)(7)(ii) (final Sec.  
1910.304(g)(8)(ii) and (g)(8)(iii)), this practice has been prohibited 
for ac circuits since the 1978 edition of the NEC. Thus, this change 
only affects a small percentage of branch circuits extended after March 
15, 1972, the date the provision went into effect and until 1979 when 
the NEC prohibition applied.
    Many employers recognized the safety hazards and the operating 
anomalies of grounding utilization equipment to the structural metal 
framing of buildings. Consequently, they have already abandoned the 
practice. Therefore, it is extremely unlikely that violations of this 
rule exist in significant numbers. After all, this practice has been 
banned for over a quarter of a century by the NEC. OSHA has concluded 
that requiring the installation of an equipment grounding conductor 
instead of allowing the structural metal frame of a building to serve 
as the equipment grounding conductor for all modifications to existing 
installations will have no appreciable cost impacts.
    The final rule also includes a new provision, final Sec.  
1910.304(b)(3)(ii)(C), that allows implementation of an assured 
equipment grounding conductor program during maintenance, remodeling, 
or repair of buildings, structures, or equipment or during similar 
construction-like activities when GFCIs are not available. OSHA has 
added costs for this provision in the analysis, as explained below.
    Final Sec.  1910.304(b)(3)(ii)(B) requires receptacles other than 
125-volt, single-phase, 15-, 20-, and 30-ampere receptacles that are 
not part of the permanent wiring of the building or structure and that 
are in use by personnel to have ground-fault circuit-interrupter 
protection for personnel. OSHA recognizes that it may be impossible for 
employers to comply with this requirement for GFCI protection for 
circuits operating at voltages above 125 volts to ground. For instance, 
portable electric welding units for the repair of major pieces of 
equipment such as industrial boilers and other massive units of 
industrial equipment generally require a 480-volt power connection 
rated 30 amperes or more. At these ratings, GFCI protection for 
personnel may not be feasible since it is not presently available for 
all branch-circuit voltage and current ratings. Therefore, the final 
rule permits an assured equipment grounding conductor (AEGC) program as 
an alternative.\65\
---------------------------------------------------------------------------

    \65\ Final Sec.  1910.304(b)(3)(ii)(C) requires the employer to 
establish and implement an assured equipment grounding conductor 
program covering cord sets, receptacles that are not a part of the 
building or structure, and equipment connected by cord and plug that 
are available for use or used by employees on those receptacles.
---------------------------------------------------------------------------

    Although OSHA believes that the AEGC program costs more to 
implement than GFCI protection for personnel (equivalent to a unit cost 
of $110 instead of $55) it could reduce compliance costs for employers 
when compared to hard-wired methods.\66\ OSHA believes that about five percent 
(one in twenty) of all temporary electric circuits may not be serviceable with 
GFCI protection for personnel at the higher current and voltage ratings 
and would require the AEGC program. The need to connect electric 
equipment with ratings other than 125 volts, single phase, 15, 20, and 
30 amperes, or 250 volts, single phase, 15 and 20 amperes \67\ 
increases as the size of the project increases. Nearly all temporary 
power requirements for smaller-sized projects, those with contract 
values under $3 million, would be serviceable with GFCI-protected 
receptacles or from nearby receptacles that are a part of the existing 
building structure. Smaller projects tend to take up minimal plant real 
estate. The work area is sandwiched among other facility equipment and 
is contained within the confines of the existing plant. Few, if any, of 
these projects would have need for the higher-power or higher-voltage 
equipment. Even if a project does need such equipment, these facilities 
typically have existing, permanently wired electric power receptacles 
that are capable of supporting loads at higher voltage and current 
ratings. Such receptacles are typically located throughout the plant on 
30-meter, maximum, intervals allowing for easy connection of portable 
electric equipment with 15-meter flexible cords. Consequently, OSHA 
estimates that the number of smaller-sized projects that require the 
AEGC program is negligible.
---------------------------------------------------------------------------

    \66\ Employers have two alternatives when GFCI protection for 
personnel is required for receptacles that are not part of the 
permanent wiring of a building or structure: (1) Implement an 
assured equipment grounding conductor program or (2) provide a hard-
wired installation, in which the equipment is wired directly to the 
circuit conductors, obviating the need for a receptacle outlet.
    \67\ GFCI protective devices for personnel protection may not 
readily available above 30 amperes at 125 volts, above 20 amperes at 
250 volts, or at higher voltages.
---------------------------------------------------------------------------

    As many as half of all medium-sized projects, those ranging from $3 
million to $25 million, would potentially require the AEGC program. 
These projects can include a sizable block of real estate such that the 
cords on portable equipment will not reach existing, permanently wired 
receptacles.
    Nearly all major projects, those larger than $25 million and 
encompassing significant plant real estate, are likely to use an AEGC 
program to comply with the standard.
    OSHA estimates that, at projects that would be required to use the 
AEGC program, they would be needed for only about five percent of 
temporary electric circuits. The remaining 95 percent of all temporary 
electric circuits can be protected by GFCIs. Over the entire universe 
of employers affected by the final rule, the estimated total cost of 
using an AEGC program instead of GFCIs is approximately $5,300.
    Table 14 presents the cost estimates for the final rule. The total 
annual incremental compliance costs associated with the new provisions 
in the final rule, for new electrical system and equipment 
installations, are estimated to be $9.6 million. The overwhelming 
majority of costs, 84.4 percent, are associated with Sec.  
1910.304(b)(3)(ii), Ground-fault circuit interrupter protection for 
personnel during temporary wiring installations. The total cost for 
this requirement is based upon the following unit estimates and 
assumptions:
    (1) GFCI power station or cord, initial cost = $55 (annualized cost 
= $30.42);
    (2) the number of required units ranges from two for establishments 
with less than 100 employees, to 10 for establishments with 100 to 499 
employees, to 50 for establishments with more than 500 employees;
    (3) the percentage of affected establishments ranges from 30 
percent for the smallest establishments to 100 percent for the largest 
establishments (Table 11); and
    (4) baseline industry compliance of 50 percent for the smallest 
establishments to 95 percent for the largest establishments (Table 12).
    Some of the costs and exposures to temporary wiring could 
potentially be incurred by employers performing construction work 
rather than general industry work. Temporary wiring for construction 
work is already covered under Subpart K of Part 1926; and, 
consequently, this analysis likely overestimates the incremental costs 
associated with the revisions to Subpart S.

E. Technological and Economic Feasibility

    As noted previously, the final rule incorporates the NFPA 70E 
recommendations developed in 2000, which are based on the 1999 NEC. The 
NFPA 70E Committee has updated the document in accordance with 
revisions to the NEC, which periodically recodifies acceptable 
electrical practices as a national consensus standard. More than 80 
percent of establishments covered by the final rule are located in 
areas that currently mandate adherence to these recommendations or the 
1999 or more stringent version of the NEC. Moreover, the vast majority 
of employers comply with the NEC in the absence of any legal 
obligation.\68\ Thus, most potentially affected parties already are in 
compliance with the final rule, which clearly demonstrates that it is 
technologically feasible. The costs of the rule are also extremely low, 
as discussed earlier in this section of the preamble. These costs do 
not threaten the long-term profitability or competitive structure of 
affected industries. Therefore, the final rule is also economically 
feasible.
---------------------------------------------------------------------------

    \68\ As noted previously, construction requirements imposed by 
mortgage lenders and insurance carriers and installation practices 
followed by licensed electricians (given their formal training) are 
reasons to expect that some employers comply with the NEC in the 
absence of any legal obligation.
---------------------------------------------------------------------------

 F. Regulatory Flexibility Screening Analysis and Regulatory 
Flexibility Certification

    In order to determine whether a regulatory flexibility analysis is 
required under the Regulatory Flexibility Act, OSHA has evaluated the 
potential economic impacts of this action on small entities. Table 15 
presents the data used in this analysis to determine whether this rule 
would have a significant impact on a substantial number of small 
entities.
    First, compliance costs were computed on a per establishment basis, 
which required consideration of the number of establishments 
potentially impacted. The analysis of County Business Patterns data 
discussed above indicated that approximately 861,400 establishments are 
in local jurisdictions in the 12 States that are either currently 
requiring compliance with the 1996 NEC or have not adopted a statewide 
electrical code applicable to private sector employers. Regarding the 
documentation provisions for new installations in hazardous locations 
(Sec.  1910.307(b) in Table 14), only industries that handle flammable 
and/or combustible liquids, vapors, gases, dusts, and/or fibers will be 
impacted. OSHA identified these industries by reviewing data on Sec.  
1910.307 citations issued between October 2000 and September 2001 
(available on the OSHA website at http://www.osha.gov/oshstats/) and 
IMIS accident data from 1994 to 2001 indicating Sec.  1910.307 
citations (OSHA, 2001). OSHA estimated that approximately 441,400 
establishments with hazardous locations are in local jurisdictions in 
the 12 States that either are currently following the 1996 NEC or have 
not adopted a statewide electrical code applicable to private sector 
employers. These are the establishments potentially impacted by the 
hazardous locations provision. The remaining provisions potentially 
affect all 861,400 establishments in the 12 States as noted above.\69\
---------------------------------------------------------------------------

    \69\ For Sec.  1910.307(b), OSHA's calculation of per-
establishment costs and impacts is based on an estimated 441,400 
affected establishments. For all other provisions of the final 
standard, OSHA's calculation of per-establishment costs and impacts 
is based on an estimated 861,400 affected establishments.
---------------------------------------------------------------------------

    OSHA assumed for purposes of conducting the regulatory flexibility 
screening analysis, that small firms, on average, will conduct the same 
type and size of projects as larger establishments. This is a 
conservative assumption, since it is more likely that smaller 
establishments will tend to perform small sized, less costly projects. 
Consequently, OSHA applied an average cost per establishment in 
analyzing the effect on small entities. The average cost per 
establishment was computed by dividing the total costs reported in 
Table 14 by the number of affected establishments reported in Table 8. 
For Provisions 1 to 5 and 7, the cost per establishment is $10.10 and 
for Provision 6, the cost per establishment is $1.92. Thus, for 
industries that handle flammable and/or combustible liquids, vapors, 
gases, dusts, and/or fibers, the total cost per establishment is 
estimated to be $12.02.
    OSHA guidelines for determining the need for regulatory flexibility 
analysis require determining the regulatory costs as a percentage of 
the revenues and profits of small entities. OSHA derived estimates of 
the profits and revenues using data from U.S. Census and Dun and 
Bradstreet. In defining a small business, OSHA followed Small Business 
Administration (SBA) criteria for each sector. For many of the affected 
industries, the SBA small business criteria are determined directly by 
the number of employees. But for those industries where the SBA small 
business criteria are not determined by the number of employees (but 
rather by annual sales), the sales-based criteria were converted to 
employment-based criteria. Specifically, an employment-based firm size 
standard was determined by first calculating an employment level, based 
on the industry average annual receipts per employee, which would be 
sufficient to produce a total sales amount per firm consistent with the 
SBA sales-based firm size standard.
    As shown in Table 15, at worst, compliance costs represent 0.005 
percent of the revenues (for SIC 72, Personal Services) and 0.15 
percent of profits (for SIC 56, Apparel and Accessory Stores). On 
average (computed by weighting by number of establishments), compliance 
costs constitute 0.002 percent of revenues and 0.048 percent of 
profits. Based on this evaluation, OSHA certifies that this rule will 
not have a significant economic impact on a substantial number of small 
entities.\70\
---------------------------------------------------------------------------

    \70\ OSHA also examined the situation where all compliance costs 
accrue to the construction sector (in SIC 1731, Electrical 
Services). In this case, costs constitute 0.04 percent of revenues 
1.3 percent of profits. Thus, even if all costs are assigned to 
construction, the proposed regulation will not have a significant 
impact on small entities.

                                            Table 7.--Changes to the Existing Standard With Cost Implications
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                                                                         Provisions
                                         Comments on cost                                                  Basis for estimating      identified in the
           Final rule \1\                     impact          Types of establishments/projects affected            costs              final rule  Sec.
                                                                                                                                     1910.302(b)(4) \2\
--------------------------------------------------------------------------------------------------------------------------------------------------------
1910.303(f)(5)......................  Requires the purchase  All Establishments........................  Projects................                     X
                                       and installation of   All Projects..............................
                                       labels.
1910.303(h)(5)(iii)(B)..............  Requires the purchase  All Establishments........................  Projects................  .....................
                                       and installation of   All Projects..............................
                                       signs.
1910.304(b)(1)......................  Requires the purchase  All Establishments........................  Projects................                     X
                                       and installation of   All Projects..............................
                                       labels and
                                       identification of
                                       branch circuits.
1910.304(b)(3)(i)...................  Requires the purchase  All Establishments........................  Projects................  .....................
                                       and installation of   All Projects..............................
                                       GFCI for bathrooms
                                       and rooftops.
1910.304(b)(3)(ii)(A) and             Requires that each     All Establishments........................  Establishments..........  .....................
 (b)(3)(ii)(B).                        affected facility     All Projects..............................
                                       purchase GFCI
                                       equipment (power
                                       stations or
                                       extension.
1910.304(b)(3)(ii)(C)...............  Requires that the      All Establishments........................  Establishments..........  .....................
                                       facility establish    All Projects..............................
                                       and implement an
                                       assured equipment
                                       grounding conductor
                                       program.
1910.306(c)(6)......................  Requires the purchase  All Establishments........................  Projects................                     X
                                       and installation of   All Projects..............................
                                       signs.
1910.306(j)(1)(iii).................  Change in design       Real Estate Development and Dwelling        Projects................                     X
                                       impacts construction   Projects.
                                       cost (near universal
                                       compliance assumed).
1910.306(k)(4)(iv)..................  Requires the purchase  Carnivals, Circuses, Fairs, and Similar     Projects................                     X
                                       and installation of    Events.
                                       labels.
1910.307(b).........................  Facility owner must    Industrial Establishments.................  Projects................                     X
                                       develop               All Projects..............................
                                       documentation.
1910.308(b)(3)......................  Requires the purchase  All Establishments........................  Projects................                     X
                                       and installation of   All Projects..............................
                                       signs.
1910.308(e)(1)......................  Change in facility     All Establishments........................  Projects................  .....................
                                       design and            Large Projects............................
                                       additional materials
                                       and installation
                                       cost.
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ Note: In the proposal, Sec.  Sec.   1910.303(e)(2)(ii) and 1910.308(a)(5)(vi)(B) and (d)(2)(ii) were mistakenly identified as paperwork requirements
  imposing a cost burden on employers. The costs for the labeling required by these provisions is borne by the manufacturers as usual and customary. In
  addition, proposed Sec.   1910.304(b)(3) has not been carried forward into the final rule. Consequently, this Final Economic Analysis does not include
  costs for these four requirements. However, OSHA has determined that final Sec.  Sec.   1910.303(f)(5), 1910.306(c)(6) and (k)(4)(iv), and
  1910.308(b)(3) do impose paperwork-associated costs on employers, but they were not included in the Preliminary Economic Analysis. Therefore, this
  Final Economic Analysis does include costs for these four provisions.
\2\ Note: Provisions listed in Sec.   1910.302(b)(4) only apply to new installations.

        Table 8.--Establishments and Employment Affected by the Final Standard, by Version of NEC Adopted
----------------------------------------------------------------------------------------------------------------
                                                                  Establishments               Employment
                                                           -----------------------------------------------------
                 Applicable version of NEC                                Percent of                 Percent of
                                                               Number        total        Number        total
----------------------------------------------------------------------------------------------------------------
1996......................................................      \1\ 0.4           6.3      \1\ 5.6           6.3
1999 or 2002..............................................      \1\ 4.8          84.7     \1\ 76.6          85.3
None......................................................      \1\ 0.5           9.0      \1\ 7.6           8.4
                                                           -----------------------------------------------------
    Total.................................................      \1\ 5.6         100       \1\ 89.8        100
----------------------------------------------------------------------------------------------------------------
Source: U.S. Dept. of Labor, OSHA, Office of Regulatory Analysis, based on 1997 County Business Patterns (U.S.
  Census Bureau) database.
\1\ In millions.


    Table 9.--Fatal and Nonfatal Occupational Injuries Attributable To Contact With Electric Current (Private
                                                    Industry)
----------------------------------------------------------------------------------------------------------------
                                              Number of        Percent of                          Percent of
                                              injuries       Total nonfatal       Number of        total fatal
                  Year                     involving days     occupational         deaths         occupational
                                           away from work       injuries                            injuries
----------------------------------------------------------------------------------------------------------------
1992....................................             4,806               0.2               317               5.8
1993....................................             4,995               0.2               303               5.4
1994....................................             6,018               0.3               332               5.6
1995....................................             4,744               0.2               327               6.0
1996....................................             4,126               0.2               268               4.8
1997....................................             3,170               0.2               282               5.0
1998....................................             3,910               0.2               324               5.9
1999....................................             4,224               0.2               259               4.7
2000....................................             3,704               0.2               256               4.8
2001....................................             3,394               0.2               285               4.8
2002....................................             2,967               0.2               289               5.2
2003....................................             2,390               0.2               246               4.4
2004....................................             2,650               0.2               254              4.4
----------------------------------------------------------------------------------------------------------------
Source: U.S. Bureau of Labor Statistics, Survey of Occupational Injuries and Illnesses and the Census of Fatal
  Occupational Injuries (http://www.bls.gov/iif/home.htm).



    Table 10.--Construction Project Starts in 2001 for States That Have Adopted the 1996 NEC or Do Not Have a
                                            Statewide Electrical Code
----------------------------------------------------------------------------------------------------------------
                                                       Size of project (contract value)
                                             ---------------------------------------------------
                Building type                   Less than $3                                          Total
                                                  million       $3-25 million    More than $25
                                                  (small)          (medium)     million (large)
----------------------------------------------------------------------------------------------------------------
Commercial and Public Buildings.............           15,219            1,490               45           16,754
Warehouses..................................            1,659              204                8            1,871
Health Facilities and Laboratories..........            1,691              245               33            1,969
Funeral and Interment Facilities............               45  ...............  ...............               45
Athletic and Entertainment Facilities.......               54                9                2               65
Auto, Bus, and Truck Service................              797               47  ...............              844
Residential Housing.........................            1,491              169                6            1,666
Apartments, Hotels and Dormitories..........            2,505              269               24            2,798
Tanks.......................................              309                8  ...............              317
Hydroelectric Power Plants..................                3  ...............  ...............                3
Natural Gas Plants..........................                2                2                1                5
Gas, Water, and Sewer Lines.................            2,340               91                1            2,432
Manufacturing Facilities....................              447               84                6              537
                                             -------------------------------------------------------------------
    Total...................................           26,562            2,618              126           29,306
----------------------------------------------------------------------------------------------------------------
Source: William R. Schriver (2002), The University of Tennessee, Knoxville, Construction Industry Research and
  Policy Center, based on F.W. Dodge data on construction project starts for 2001.

           Table 11.--Estimated Percentages of Projects/Establishments Affected by the Final Standard
                                  [By provision and project/establishment size]
----------------------------------------------------------------------------------------------------------------
                                                                                  Project/establishment size
                                                                             -----------------------------------
    Provision No.             Final rule         Description of requirement      Small      Medium       Large
                                                                               (percent)   (percent)   (percent)
----------------------------------------------------------------------------------------------------------------
1....................  1910.303(f)(5).........  Marking for series                    50          50          50
                                                 combination ratings.
2....................  1910.303(h)(5)(iii)(B).  Working Space and Guarding--          50         100         100
                                                 Posting of Warning Signs.
1a...................  1910.304(b)(1).........  Branch Circuits--                     50          50          50
                                                 Identification of Multiwire
                                                 Branch Circuits.
3....................  1910.304(b)(3)(i)......  Ground-fault circuit                 100         100         100
                                                 interrupter protection for
                                                 bathrooms and rooftops.
4....................  1910.304(b)(3)(ii)(A)    Ground-fault circuit                  30          80         100
                        and (b)(3)(ii)(B).       interrupter protection for
                                                 temporary wiring
                                                 installations.
4a...................  1910.304(b)(3)(ii)(C)..  Assured equipment grounding            0          50         100
                                                 conductor program for
                                                 temporary wiring
                                                 installations.
1b...................  1910.306(c)(6).........  Identification and signs for          50          50          50
                                                 elevators, dumbwaiters,
                                                 escalators, moving walks,
                                                 wheelchair lifts, and
                                                 stairway chair lifts.
5....................  1910.306(j)(1)(iii)....  Swimming Pools, Fountains,            20          80         100
                                                 and Similar Installations--
                                                 Receptacles.
1c...................  1910.306(k)(4)(iv).....  Marking for single-pole               50          50          50
                                                 portable cable connectors
                                                 for parallel sets of
                                                 conductors used in
                                                 installations for
                                                 carnivals, circuses, fairs,
                                                 and similar events.
6....................  1910.307(b)............  Hazardous (Classified)                60          80         100
                                                 Locations--Documentation.
1d...................  1910.308(b)(3).........  Signs for emergency power             50          50          50
                                                 systems.
7....................  1910.308(e)(1).........  Communication Systems--                5          60        100
                                                 Protective Devices.
----------------------------------------------------------------------------------------------------------------
 Source: OSHA estimates, based on experience and knowledge of electrical practices.


      Table 12.--Estimated Percentages for Baseline Compliance, by Provision and Project/Establishment Size
----------------------------------------------------------------------------------------------------------------
                                                                                  Project/establishment size
                                                                             -----------------------------------
    Provision No.             Final rule         Description of requirement      Small      Medium       Large
                                                                               (percent)   (percent)   (percent)
----------------------------------------------------------------------------------------------------------------
1....................  1910.303(f)(5).........  Marking for series                    25          25          50
                                                 combination ratings.
2....................  1910.303(h)(5)(iii)(B).  Working Space and Guarding--          25          25          50
                                                 Posting of Warning Signs.
1a...................  1910.304(b)(1).........  Branch Circuits--                     25          25          50
                                                 Identification of Multiwire
                                                 Branch Circuits.
3....................  1910.304(b)(3)(i)......  Ground-fault circuit                  50          95          95
                                                 interrupter protection for
                                                 bathrooms and rooftops.
4....................  1910.304(b)(3)(ii)(A)    Ground-fault circuit                  50          95          95
                        and (b)(3)(ii)(B).       interrupter protection for
                                                 temporary wiring
                                                 installations.
4a...................  1910.304(b)(3)(ii)(C)..  Assured equipment grounding            0           5           5
                                                 conductor program for
                                                 temporary wiring
                                                 installations.
1b...................  1910.306(c)(6).........  Identification and signs for          25          25          50
                                                 elevators, dumbwaiters,
                                                 escalators, moving walks,
                                                 wheelchair lifts, and
                                                 stairway chair lifts.
5....................  1910.306(j)(1)(iii)....  Swimming Pools, Fountains,            60          90          90
                                                 and Similar Installations--
                                                 Receptacles.
1c...................  1910.306(k)(4)(iv).....  Marking for single-pole               25          25          50
                                                 portable cable connectors
                                                 for parallel sets of
                                                 conductors used in
                                                 installations for
                                                 carnivals, circuses, fairs,
                                                 and similar events.
6....................  1910.307(b)............  Hazardous (Classified)                50          80          80
                                                 Locations--Documentation.
1d...................  1910.308(b)(3).........  Signs for emergency power             25          25          50
                                                 systems.
7....................  1910.308(e)(1).........  Communication Systems--               10          30         40
                                                 Protective Devices.
----------------------------------------------------------------------------------------------------------------
 Source: OSHA estimates, based on experience and knowledge of electrical practices.


  Table 13.--Data and Bases for Unit Costs Applied in OSHA's Final Cost
                                Analysis
------------------------------------------------------------------------
 Provision No.       Final rule      Labor costs \1\     Material costs
------------------------------------------------------------------------
1..............  1910.303(f)(5),    Average of 2       Average cost of
                  1910.304(b)(1),    minutes of labor   label or sign:
                  1910.306(c)(6),    for each           $2.
                  1910.306(k)(4)(i   provision to
                  v) and             install label at
                  1910.308(b)(3).    $28/hour ($20.44
                                     x 1.37).
2..............  1910.303(h)(5)(ii  1 minute of labor  Cost of label:
                  i)(B).             to install label   $1.
                                     at $28/hour
                                     ($20.44 x 1.37).
3..............  1910.304(b)(3)(i)  None.............  GFCI: $5.
4..............  1910.304(b)(3)(ii  None.............  GFCI power
                  )(A) and                              station or cord:
                  (b)(3)(ii)(B).                        $55 each,
                                                        annualized over
                                                        2-year useful
                                                        life.
4a.............  (b)(3)(ii)(C) \2\  None.............  AEGC $110
                                                        (equivalent
                                                        cost).
5..............  1910.306(j)(1)(ii  3 hours at $28/    Various conduit,
                  i).                hour ($20.44 x     connectors,
                                     1.37).             outlets: $75.
6..............  1910.307(b)......  4 hours at $28/    None.
                                     hour ($20.44 x
                                     1.37).
7..............  1910.308(e)(1)...  1 minute of labor  Cost of label:
                                     to install label   $1.
                                     at $28/hour
                                     ($20.44 x 1.37).
------------------------------------------------------------------------
\1\ Note: The wage rate data are for 2000, taken from the BLS (2001)
  2000 National Occupational Employment Statistics (OES) Survey. Fringe
  benefit rate data are from BLS (2000) Employer Costs for Employee
  Compensation, March. USDL: 00-186.
\2\ Note: See the discussion of the methodology for estimating costs
  associated with the assured equipment grounding conductor program
  earlier in this section of the preamble.
Source: U.S. Dept. of Labor, OSHA, Office of Regulatory Analysis, 2006.


           Table 14.--Annual Incremental Compliance Costs for Changes to Subpart S Electrical Standard
----------------------------------------------------------------------------------------------------------------
                                                                   Annual costs for projects/establishments \1\
  Provision No.         Final rule           Description of      -----------------------------------------------
                                               requirement           Total       Small      Medium       Large
----------------------------------------------------------------------------------------------------------------
1................  1910.303(f)(5).....  Marking for series          $346,208    $221,365    $109,091     $15,751
                                         combination ratings.
2................  1910.303(h)(5)(ii)(  Working Space and             66,839      49,141      16,145       1,554
                    B).                  Guarding--Posting of
                                         Warning Signs.
                                                                 -----------------------------------------------
1a...............  1910.304(b)(1).....  Branch Circuits--                    Included in Provision 1.
                                         Identification of
                                         Multiwire Branch
                                         Circuits.
                                                                 -----------------------------------------------
3................  1910.304(b)(3)(i)..  Ground-fault circuit         141,336     132,810       6,872       1,654
                                         interrupter protection
                                         for bathrooms and
                                         rooftops.
4................  1910.304(b)(3)(ii)(  Ground-fault circuit       8,057,529   7,686,276     206,832     164,420
                    A) and               interrupter protection
                    (b)(3)(ii)(B).       for temporary wiring
                                         installations.
4a...............  1910.304(b)(3)(ii)(  Assured equipment              5,332           0       3,600       1,733
                    C).                  grounding conductor
                                         program for temporary
                                         wiring installations.
                                                                 -----------------------------------------------
1b...............  1910.306(c)(6).....  Identification and signs             Included in Provision 1.
                                         for elevators,
                                         dumbwaiters,
                                         escalators, moving
                                         walks, wheelchair
                                         lifts, and stairway
                                         chair lifts.
                                                                 -----------------------------------------------
5................  1910.306(j)(1)(iii)  Swimming Pools,               36,050      31,865       3,422         763
                                         Fountains, and Similar
                                         Installations--Receptac
                                         les.
                                                                 -----------------------------------------------
1c...............  1910.306(k)(4)(iv).  Marking for single-pole              Included in Provision 1.
                                         portable cable
                                         connectors for parallel
                                         sets of conductors used
                                         in installations for
                                         carnivals, circuses,
                                         fairs, and similar
                                         events.
                                                                 -----------------------------------------------
6................  1910.307(b)........  Hazardous (Classified)       846,930     756,479      77,816      12,635
                                         Locations--Documentatio
                                         n.
                                                                 -----------------------------------------------
1d...............  1910.308(b)(3).....  Signs for emergency                  Included in Provision 1.
                                         power systems.
                                                                 -----------------------------------------------
7................  1910.308(e)(1).....  Communication Systems--       51,044       8,172      37,593       5,280
                                         Protective Devices.
                                                                 -----------------------------------------------
    Total........  ...................  ........................   9,550,457   8,886,108     460,716     203,633
----------------------------------------------------------------------------------------------------------------
\1\ The total cost per establishment is estimated to be $12.36 for industries that handle flammable and/or
  combustible liquids, vapors, gases, dusts, and/or fibers and $10.44 for all other industries.
Source: U.S. Dept. of Labor, OSHA, Office of Regulatory Analysis, 2006.
Note: Compliance costs for all provisions except 4 are based on projects. Compliance costs for provision 4 are
  based on establishments (small establishments have 1-99 employees medium establishments have 100-499
  employees, and large establishments have 500+ employees).


                                                         Table 15.--Impacts on Small Businesses
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                                                                    Cost as a
                                                             Number of    Small business    Revenue per     Profit     Profit per    percent   Cost as a
            SIC \1\                Industry description   small business     revenues      establishment   rate (%)  establishment      of      percent
                                                          establishments      ($1000)                                                revenue   of profit
--------------------------------------------------------------------------------------------------------------------------------------------------------
700............................  Agricultural services..       109,663       $38,501,047        $351,085       6.02      $21,130       0.0029     0.0478
800............................  Forestry...............         2,400         1,496,747         623,645      10.30       64,235       0.0016     0.0157
900............................  Fishing, hunting, and              NA                NA              NA       5.80           NA           NA         NA
                                  trapping.
1300...........................  Oil And Gas Extraction.        14,787        29,931,841       2,024,200       8.65      175,093       0.0006     0.0069
1500...........................  General building              195,315       234,203,450       1,199,106       4.00       47,964       0.0008     0.0211
                                  contractors.
1600...........................  Heavy construction,            35,618        68,664,092       1,927,792       4.00       77,112       0.0005     0.0131
                                  except building.
1700...........................  Special trade                 426,477       270,401,924         634,036       4.00       25,361       0.0016     0.0398
                                  contractors.
2000...........................  Food And Kindred               15,992       104,629,113       6,542,591       3.46      226,600       0.0002     0.0053
                                  Products.
2100...........................  Tobacco Products.......            91         1,255,255      13,794,011       4.02      554,130       0.0001     0.0022
2200...........................  Textile Mill Products..         4,845        20,377,246       4,205,830       2.77      116,423       0.0003     0.0103
2300...........................  Apparel And Other              22,383        38,507,048       1,720,370       2.56       44,010       0.0007     0.0273
                                  Textile Products.
2400...........................  Lumber And Wood                35,076        58,343,756       1,663,353       3.90       64,854       0.0007     0.0185
                                  Products.
2500...........................  Furniture And Fixtures.        11,217        26,295,821       2,344,283       3.51       82,285       0.0005     0.0146
2600...........................  Paper And Allied                4,057        31,334,277       7,723,509       4.50      347,629       0.0002     0.0035
                                  Products.
2700...........................  Printing And Publishing        57,018        85,620,541       1,501,641       3.80       57,055       0.0008     0.0211
2800...........................  Chemicals And Allied            8,227        59,010,014       7,172,726       4.49      321,776       0.0002     0.0037
                                  Products.
2900...........................  Petroleum And Coal              1,047        13,950,653      13,324,406       2.99      398,317       0.0001     0.0030
                                  Products.
3000...........................  Rubber And Misc.               13,043        58,709,872       4,501,255       4.02      181,167       0.0003     0.0066
                                  Plastics Products.
3100...........................  Leather And Leather             1,675         4,003,751       2,390,299       2.20       52,509       0.0005     0.0229
                                  Products.
3200...........................  Stone, Clay, And Glass         11,791        34,254,470       2,905,137       4.93      143,127       0.0004     0.0084
                                  Products.
3300...........................  Primary Metal                   4,806        36,511,582       7,597,083       4.52      343,213       0.0002     0.0035
                                  Industries.
3400...........................  Fabricated Metal               34,250       113,752,781       3,321,249       4.55      150,988       0.0004     0.0080
                                  Products.
3500...........................  Industrial Machinery           52,548       127,178,710       2,420,239       4.05       97,917       0.0005     0.0123
                                  And Equipment.
3600...........................  Electronic & Other             14,355        69,499,940       4,841,514       5.59      270,705       0.0002     0.0044
                                  Electric Equipment.
3700...........................  Transportation                 10,653        41,544,504       3,899,794       3.74      145,974       0.0003     0.0082
                                  Equipment.
3800...........................  Instruments And Related        10,190        33,908,725       3,327,647       5.06      168,410       0.0004     0.0071
                                  Products.
3900...........................  Miscellaneous                  17,837        30,627,905       1,717,100       3.80       65,322       0.0007     0.0184
                                  Manufacturing
                                  Industries.
4000...........................  Railroad transportation            NA                NA              NA      11.08           NA           NA         NA
4100...........................  Local and interurban           16,537         7,690,615         465,055       4.51       20,964       0.0022     0.0482
                                  passenger transit.
4200...........................  Trucking And                  114,623        79,888,400         696,967       3.91       27,278       0.0017     0.0441
                                  Warehousing.
4400...........................  Water Transportation...         8,051        14,075,608       1,748,306       7.48      130,855       0.0007     0.0092
4500...........................  Transportation by air..         6,386        15,156,218       2,373,351       3.62       85,925       0.0004     0.0118
4600...........................  Pipelines, Except                  39           986,979      25,307,154       6.55    1,657,050       0.0000     0.0007
                                  Natural Gas.
4700...........................  Transportation Services        40,529        19,513,397         481,468       3.39       16,327       0.0025     0.0736
4800...........................  Communications.........        17,482        41,125,079       2,352,424       5.58      131,244       0.0004     0.0077
4900...........................  Electric, Gas, And              8,938        10,824,146       1,211,026      10.37      125,641       0.0010     0.0096
                                  Sanitary Services.
5000...........................  Wholesale Trade--             258,492       837,107,306       3,238,426       2.54       82,401       0.0004     0.0146
                                  Durable Goods.
5100...........................  Wholesale Trade--             143,751       637,454,650       4,434,436       4.46      197,917       0.0003     0.0061
                                  Nondurable Goods.
5200...........................  Building Materials &           46,450        37,776,200         813,266       2.37       19,289       0.0015     0.0623
                                  Garden Supplies.
5300...........................  General Merchandise             8,796         3,346,901         380,503       2.70       10,283       0.0027     0.0982
                                  Stores.
5400...........................  Food Stores............       123,572       101,566,550         821,922       1.41       11,595       0.0012     0.0871
5500...........................  Automotive Dealers &          116,015       149,337,410       1,287,225       1.45       18,609       0.0009     0.0646
                                  Service Stations.
5600...........................  Apparel And Accessory          50,308        18,706,435         371,838       1.85        6,867       0.0027     0.1471
                                  Stores.
5700...........................  Home Furniture And             78,842        45,392,798         575,744       2.28       13,142       0.0018     0.0768
                                  Furnishings Stores.
5800...........................  Eating And Drinking           355,297       128,561,814         361,843       3.00       10,850       0.0033     0.1108
                                  Places.
5900...........................  Miscellaneous Retail...       258,538       119,265,615         461,308       2.49       11,479       0.0026     0.1047
6000...........................  Depository Institutions        14,378        15,538,559       1,080,718      10.80      116,718       0.0009     0.0087
6100...........................  Nondepository                  21,262        13,454,697         632,805      15.05       95,230       0.0016     0.0106
                                  Institutions.
6200...........................  Security And Commodity         27,262        19,644,662         720,588      13.32       95,949       0.0014     0.0105
                                  Brokers.
6300...........................  Insurance Carriers.....         4,967         5,850,805       1,177,935       6.82       80,375       0.0009     0.0126
6400...........................  Insurance Agents,             119,907        47,083,678         392,668       6.83       26,800       0.0026     0.0377
                                  Brokers, & Service.
6500...........................  Real Estate............       230,304       142,479,284         618,657      13.31       82,340       0.0016     0.0123
6700...........................  Holding And Other              21,022        35,174,755       1,673,235      24.01      401,733       0.0006     0.0025
                                  Investment Offices.
7000...........................  Hotels And Other               47,698        24,876,889         521,550       6.96       36,302       0.0019     0.0278
                                  Lodging Places.
7200...........................  Personal Services......       176,477        36,957,629         209,419       5.86       12,262       0.0048     0.0824
7300...........................  Business Services......       337,126       188,061,601         557,838       4.79       26,703       0.0022     0.0450
7500...........................  Auto Repair, Services,        167,057        66,003,052         395,093       4.39       17,356       0.0030     0.0692
                                  And Parking.
7600...........................  Miscellaneous Repair           63,328        25,861,556         408,375       5.44       22,198       0.0029     0.0541
                                  Services.
7800...........................  Motion Pictures........        29,959        13,026,870         434,823       5.14       22,341       0.0023     0.0452
7900...........................  Amusement & Recreation         90,742        47,922,810         528,122       4.28       22,604       0.0023     0.0532
                                  Services.
8000...........................  Health Services........       413,561       243,370,668         588,476       6.17       36,312       0.0020     0.0331
8100...........................  Legal Services.........       156,877        54,265,197         345,909      17.50       60,534       0.0029     0.0167
8200...........................  Educational Services...        40,592        25,677,552         632,577       8.14       51,502       0.0016     0.0196
8300...........................  Social Services........       117,544        50,553,841         430,084       4.44       19,088       0.0023     0.0529
8400...........................  Museums, Botanical,             4,912         2,928,264         596,145      21.45      127,873       0.0017     0.0079
                                  Zoological Gardens.
8600...........................  Membership                    242,081        78,452,141         324,074       7.21       23,371       0.0031     0.0432
                                  Organizations.
8700...........................  Engineering and               271,169       151,671,072         559,323       6.39       35,745       0.0018     0.0283
                                  management services.
8900...........................  Services, n.e.c........        16,395         8,169,059         498,265       6.80       33,882       0.0020     0.0298
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ Consistent with the preliminary analysis, OSHA in this final analysis has grouped affected industries according to the 1987 Standard Industrial
  Classification System. For industry coding under the North American Industry Classification System (NAICS), see NAICS, Executive Office of the
  President, Office of Management and Budget, 1997 and 2002.
Source: U.S. Dept. of Labor, OSHA, Office of Regulatory Analysis, 2006, based on U.S. Census Bureau, 2001, and Dun & Bradstreet, 2001.

VII. State Plan Standards

    The 26 States or territories with OSHA-approved occupational safety 
and health plans must adopt an equivalent amendment or one that is at 
least as protective to employees within 6 months of the publication 
date of the final standard. These are: Alaska, Arizona, California, 
Connecticut (for State and local government employees only), Hawaii, 
Indiana, Iowa, Kentucky, Maryland, Michigan, Minnesota, Nevada, New 
Mexico, New Jersey (for State and local government employees only), New 
York (for State and local government employees only), North Carolina, 
Oregon, Puerto Rico, South Carolina, Tennessee, Utah, Vermont, 
Virginia, Virgin Islands, Washington, and Wyoming.

VIII. Environmental Impact Analysis

    The final rule's provisions have been reviewed in accordance with 
the requirements of the National Environmental Policy Act (NEPA) of 
1969 (42 U.S.C. 4321, et seq.), the regulations of the Council on 
Environmental Quality (40 CFR Part 1502), and the Department of Labor's 
NEPA procedures (29 CFR Part 11). As a result of this review, OSHA has 
determined that these provisions will have no significant effect on 
air, water or soil quality, plant or animal life, on the use of land, 
or other aspects of the environment.

IX. Unfunded Mandates

    This final rule has been reviewed in accordance with the Unfunded 
Mandates Reform Act of 1995 (UMRA) (2 U.S.C. 1501 et seq.). For the 
purposes of the UMRA, the Agency certifies that this final rule does 
not impose any Federal mandate that may result in increased 
expenditures by State, local, or tribal governments, or increased 
expenditures by the private sector, of more than $100 million in any 
year.

X. Federalism

    OSHA has reviewed this rule in accordance with the Executive Order 
on Federalism (Executive Order 13132, 64 FR 43255, August 10, 1999), 
which requires that agencies, to the extent possible, refrain from 
limiting State policy options, consult with States prior to taking any 
actions that would restrict State policy options, and take such actions 
only when there is clear constitutional authority and the presence of a 
problem of national scope. The Order provides for preemption of State 
law only if there is a clear Congressional intent for the Agency to do 
so. Any such preemption is to be limited to the extent possible.
    Section 18 of the OSH Act expresses Congress's intent to preempt 
State laws where OSHA has promulgated occupational safety and health 
standards. A State can avoid preemption on issues covered by Federal 
standards only if it submits, and obtains Federal approval of, a plan 
for the development of such standards and their enforcement. 29 U.S.C. 
667, Gade v. National Solid Wastes Management Association, 505 U.S. 88 
(1992). Occupational safety and health standards developed by such Plan 
States must, among other things, be at least as effective in providing 
safe and healthful employment and places of employment as the Federal 
standards. Subject to the statutory limitations of the OSH Act, State-
Plan States are free to develop and enforce their own requirements for 
occupational safety and health protections.
    Although OSHA has a clear statutory mandate to preempt State 
occupational safety and health laws, States may enforce standards, such 
as State and local fire and building codes, which are designed to 
protect a wider class of persons than employees. As discussed earlier, 
the final rule introduces few new requirements that are not already 
mandated by applicable State and local law. In fact, most States and 
municipalities require compliance with the NEC, which is consistent 
with the final rule.

XI. OMB Review Under the Paperwork Reduction Act of 1995

    The final rule Electrical Standard contains several collection-of-
information (paperwork) requirements that are subject to review by the 
Office of Management and Budget (OMB) under the Paperwork Reduction Act 
of 1995 (PRA-95), 44 U.S.C. 3501 et seq., and OMB's regulations at 5 
CFR part 1320. PRA-95 defines "collection of information" as "the 
obtaining, causing to be obtained, soliciting, or requiring the 
disclosure to third parties or the public of facts or opinions by or 
for an agency regardless of form or format * * *" (44 U.S.C. 
3502(3)(A)). The collection-of-information requirements contained in 
the proposed Design Safety Standards for Electrical Systems was 
submitted to OMB on April 2, 2004. On December 7, 2004, OMB provided 
the following comment regarding its review of the paperwork 
requirements contained in the proposed rule:

    The information collection provisions associated with the Design 
Safety Standards for Electrical Systems proposed rule are not 
approved at this time. OSHA will examine public comment in response 
to the [Notice of Proposed Rulemaking] and will describe in the 
preamble of the final rule how the [A]gency has maximized the 
practical utility of the collection and minimized its burden.

    In the preamble to the proposed rule, OSHA asked for comments on 
each of the paperwork requirements in the Electrical Standard for 
general industry, Subpart S. OSHA received no comments on the paperwork 
burdens or OSHA's estimation of those burdens. However, OSHA added a 
provision to the standard based on comments received on the proposed 
GFCI requirements. In response to those comments, the Agency added a 
requirement for the assured equipment grounding conductor program under 
limited conditions. This new provision will add 203 hours to the 
paperwork burden.
    The collection-of-information requirements contained in the final 
rule also include requirements in Sec.  1910.303 for marking series 
combination ratings, Sec.  1910.304--Wiring design and protection, 
Sec.  1910.306--Specific purpose equipment and installations, Sec.  
1910.307--Hazardous (classified) locations, and Sec.  1910.308--Special 
systems. The final Information-Collection Request estimates the total 
burden hours associated with the collection-of-information requirements 
to be approximately 9,353 hours and estimates the cost for maintenance 
and operation to be approximately $3,750. OMB is currently reviewing 
OSHA's request for approval of the collection-of-information 
requirements in the final rule.
    These collection-of-information requirements are needed to provide 
electrical safety to employees against the electric shock hazards that 
might be present in the workplace. The marking of electric equipment 
with proper ratings, identifying the phase and system of each 
ungrounded conductor, labeling certain disconnecting means with 
indentification signs, using the assured equipment grounding conductor 
program whenever approved GFCIs are not available, and documenting 
hazardous classified areas are all ways of reducing the electrical 
hazards posed on employees. OSHA will use the records developed in 
response to this standard to determine compliance. The employer's 
failure to generate and disclose the information required in this 
standard will affect significantly OSHA's effort to control and reduce 
injuries and fatalities related to electrical hazards in the workplace.
    OSHA minimized the burden hours imposed by collections of 
information contained in the standard by relying heavily on the 
National Electrical Code and NFPA 70E, Standard for Electrical Safety 
Requirements for Employee Workplaces. The collections of information in 
the standard mirror current industry practice and, therefore, impose 
minimal burden on employers and eliminate any confusion between current 
industry practice and the standard. The Agency believes that the 
information-collection frequencies required by the standard are the 
minimum frequencies necessary to effectively regulate the electrical 
hazards posed by the workforce.
    Potential respondents are not required to respond to the 
information collection requirements until they have been approved and a 
currently valid OMB control number is displayed. OMB is currently 
reviewing OSHA's request for approval of the 29 CFR Part 1910 Subpart S 
information collections. OSHA will publish a subsequent Federal 
Register document when OMB takes further action on the information 
collection requirements in the Electrical Standards rule.

XII. Effective Date and Date of Application

    The scope and application of Subpart S is set forth in Sec.  
1910.302 in paragraphs (b)(1) through (b)(4). The paragraphs are as 
follows: (b)(1) all installations regardless of when the installation 
was built; (b)(2) all installations built after March 15, 1972; (b)(3) 
all installations built after April 16, 1981; and (b)(4) all 
installations built after the final rule is published.
    In the preamble to the Proposal, OSHA proposed to make some new 
requirements effective 90 days after the final rule is published. We 
invited comments on whether this time is sufficient to implement the 
changes required by the revised standard.
    International Paper stated that companies will need at least 90 
days to effectively communicate and implement the provisions in the 
standard, even within a large organization (Ex. 3-6). They further 
stated that this period would allow companies to develop and update 
site specific electrical safety programs and would allow large 
companies to develop policies supplemental to the OSHA standards as 
well as adequately address site issues and concerns. In addition, they 
noted that the current electrical design and installation would need to 
be reviewed for compliance. They stated that the proposed changes to 
the depth of working space in front of electrical equipment, and 
proposed changes to elevation requirements to unguarded live parts of 
electrical equipment, for example, may necessitate design or 
construction changes.
    Two commenters did not believe that 90 days after the final rule is 
published would be enough time for employers to effectively implement 
the new requirements proposed in the electrical standard, especially in 
states not mandating the latest codes (Exs. 3-3, 3-10). These 
commenters recommended that the effective date be 180 days after the 
final rule is published. One of these commenters, Duke Energy 
Corporation, argued that additional time would be needed for employers 
to determine compliance and then retrofit installations if necessary. 
The other commenter, ORC World Wide, said that employers need to 
determine how the new requirements apply to their installations and 
plan accordingly. They argued that the standard is complex and may take 
companies time to understand and assimilate the standard into their 
operations.
    OSHA agrees with the public comments on the effective date and 
recognizes that companies may need additional time to implement the 
standard. For the reasons given by these commenters, the Agency will 
grant the request to extend the effective date to 180 days after the 
final rule is published.
    Accordingly, the effective date of this final rule is 180 days 
after publication. The 180-day period between the issuance of the 
standard and their effective date is intended to provide sufficient 
time for employers and employees to become informed of and comply with 
the requirements of the standard.
    The standards currently found in the existing Subpart S (Sec. Sec.  
1910.302 through 1910.308) remain in effect until the standards 
contained in this rule actually go into effect. Should the new 
standards be stayed, judicially or administratively, or should the 
standards not sustain legal challenge under section 6(f) of the OSH 
Act, the existing standards in Subpart S will remain in effect.
    Any petitions for administrative reconsiderations of these 
standards or for an administrative stay pending judicial review must be 
filed with the Assistant Secretary of Labor for Occupational Safety and 
Health on or before April 16, 2007. Any petitions filed after this day 
will be considered to be filed untimely.
    As discussed fully in the summary and explanation of final Sec.  
1910.302(b), in section V. earlier in this preamble, OSHA is making the 
new requirements in revised Subpart S effective 180 days after the 
final rule is published in the Federal Register. It should be noted 
that applying new provisions only to new installations is the same 
approach that OSHA took in promulgating the current version of Subpart 
S in 1981. The Agency found that this approach was successful and has 
no indication that it was unduly burdensome or insufficiently 
protective.

List of Subjects in 29 CFR Part 1910

    Electric power, Fire prevention, Hazardous substances, Occupational 
safety and health, Safety.

Authority and Signature

    This document was prepared under the direction of Edwin G. Foulke, 
Jr., Assistant Secretary of Labor for Occupational Safety and Health, 
200 Constitution Avenue, NW., Washington, DC 20210.

    This action is taken pursuant to sections 4, 6, and 8 of the 
Occupational Safety and Health Act of 1970 (29 U.S.C. 653, 655, 657), 
Secretary of Labor's Order No. 5-2002 (67 F.R. 65008), and 29 CFR Part 
1911.

    Signed at Washington, DC, this 24th day of January, 2007.
Edwin G. Foulke, Jr.,
Assistant Secretary of Labor.

PART 1910--[AMENDED]

0
Part 1910 of Title 29 of the Code of Federal Regulations is amended as 
follows:

Subpart A--General

0
1. The authority citation for Subpart A is revised to read as follows:

    Authority: Sections 4, 6, and 8 of the Occupational Safety and 
Health Act of 1970 (29 U.S.C. 653, 655, and 657); Secretary of 
Labor's Order No. 12-71 (36 FR 8754), 8-76 (41 FR 25059), 9-83 (48 
FR 35736), 1-90 (55 FR 9033), 6-96 (62 FR 111), 3-2000 (65 FR 
50017), or 5-2002 (67 FR 65008), as applicable.
    Sections 1910.6, 1910.7, and 1910.8 also issued under 29 CFR 
part 1911. Section 1910.7(f) also issued under 31 U.S.C. 9701, 29 
U.S.C. 9 a, 5 U.S.C. 553; Public Law 106-113 (113 Stat. 1501A-222); 
and OMB Circular A-25 (dated July 8, 1993) (58 FR 38142, July 15, 
1993).

0
2. Section 1910.6 is amended by revising the introductory text to 
paragraph (e), removing and reserving paragraph (e)(33), revising the 
introductory text to paragraph (q), and removing and reserving 
paragraph (q)(16). The revised text reads as follows:


Sec.  1910.6  Incorporation by reference.

* * * * *
    (e) The following material is available for purchase from the 
American National Standards Institute (ANSI), 25 West 43rd Street, 
Fourth Floor, New York, NY 10036:
* * * * *
    (q) The following material is available for purchase from the 
National Fire Protection Association (NFPA), 1 Batterymarch Park, 
Quincy, MA 02269:
* * * * *

Subpart F--Powered Platforms, Manlifts, and Vehicle-Mounted Work 
Platforms

0
3. The authority citation for Subpart F is revised to read as follows:

    Authority: Secs. 4, 6, and 8 of the Occupational Safety and 
Health Act of 1970 (29 U.S.C. 653, 655, and 657); Secretary of 
Labor's Order No. 12-71 (36 FR 8754), 8-76 (41 FR 25059), 9-83 (48 
FR 35736), 1-90 (55 FR 9033), or 5-2002 (67 FR 65008), as 
applicable; and 29 CFR part 1911.


0
4. Appendix D to Sec.  1910.66 is amended as follows:
0
a. Paragraph (c)(22)(i) is revised as set forth below.
0
b. In the second sentence of paragraph (c)(22)(vii), the words 
"Article 610 of the National Electrical Code, NFPA 70-1971; ANSI C1-
1971 (Rev. of C1-1968)" are revised to read "Subpart S of this 
Part."

Sec.  1910.66  Powered platforms for building maintenance.

* * * * *

Appendix D to Sec.  1910.66--Existing Installations (Mandatory)

* * * * *
    (c) * * *
    (22) * * * (i) All electrical equipment and wiring shall conform 
to the requirements of Subpart S of this Part, except as modified by 
ANSI A120.1--1970 "American National Standard Safety Requirements 
for Powered Platforms for Exterior Building Maintenance" (see Sec.  
1910.6). For detail design specifications for electrical equipment, 
see Part 2, ANSI A120.1-1970.
* * * * *

Subpart S--Electrical

0
5. The authority citation for Subpart S is revised to read as follows:

    Authority: Secs. 4, 6, 8, Occupational Safety and Health Act of 
1970 (29 U.S.C. 653, 655, 657); Secretary of Labor's Order No. 8-76 
(41 FR 25059), 1-90 (55 FR 9033), or 5-2002 (67 F.R. 65008), as 
applicable; 29 CFR Part 1911.

0
6. Sections 1910.302 through 1910.308 are revised to read as follows:

Design Safety Standards for Electrical Systems


Sec.  1910.302  Electric utilization systems.

    Sections 1910.302 through 1910.308 contain design safety standards 
for electric utilization systems.
    (a) Scope--(1) Covered. The provisions of Sec. Sec.  1910.302 
through 1910.308 cover electrical installations and utilization 
equipment installed or used within or on buildings, structures, and 
other premises, including:
    (i) Yards;
    (ii) Carnivals;
    (iii) Parking and other lots;
    (iv) Mobile homes;
    (v) Recreational vehicles;
    (vi) Industrial substations;
    (vii) Conductors that connect the installations to a supply of 
electricity; and
    (viii) Other outside conductors on the premises.
    (2) Not covered. The provisions of Sec. Sec.  1910.302 through 
1910.308 do not cover:
    (i) Installations in ships, watercraft, railway rolling stock, 
aircraft, or automotive vehicles other than mobile homes and 
recreational vehicles;
    (ii) Installations underground in mines;
    (iii) Installations of railways for generation, transformation, 
transmission, or distribution of power used exclusively for operation 
of rolling stock or installations used exclusively for signaling and 
communication purposes;
    (iv) Installations of communication equipment under the exclusive 
control of communication utilities, located outdoors or in building 
spaces used exclusively for such installations; or
    (v) Installations under the exclusive control of electric utilities 
for the purpose of communication or metering; or for the generation, 
control, transformation, transmission, and distribution of electric 
energy located in buildings used exclusively by utilities for such 
purposes or located outdoors on property owned or leased by the utility 
or on public highways, streets, roads, etc., or outdoors by established 
rights on private property.
    (b) Extent of application--(1) Requirements applicable to all 
installations. The following requirements apply to all electrical 
installations and utilization equipment, regardless of when they were 
designed or installed:

Sec.  1910.303(b)--Examination, installation, and use of equipment
Sec.  1910.303(c)(3)--Electrical connections--Splices
Sec.  1910.303(d)--Arcing parts
Sec.  1910.303(e)--Marking
Sec.  1910.303(f), except (f)(4) and (f)(5)--Disconnecting means and 
circuits
Sec.  1910.303(g)(2)--600 volts or less--Guarding of live parts
Sec.  1910.304(a)(3)--Use of grounding terminals and devices
Sec.  1910.304(f)(1)(i), (f)(1)(iv), and (f)(1)(v)--Overcurrent 
protection--600 volts, nominal, or less
Sec.  1910.304(g)(1)(ii), (g)(1)(iii), (g)(1)(iv), and (g)(1)(v)--
Grounding--Systems to be grounded
Sec.  1910.304(g)(4)--Grounding--Grounding connections
Sec.  1910.304(g)(5)--Grounding--Grounding path
Sec.  1910.304(g)(6)(iv)(A) through (g)(6)(iv)(D), and (g)(6)(vi)--
Grounding--Supports, enclosures, and equipment to be grounded
Sec.  1910.304(g)(7)--Grounding--Nonelectrical equipment
Sec.  1910.304(g)(8)(i)--Grounding--Methods of grounding fixed 
equipment
Sec.  1910.305(g)(1)--Flexible cords and cables--Use of flexible cords 
and cables
Sec.  1910.305(g)(2)(ii) and (g)(2)(iii)--Flexible cords and cables--
Identification, splices, and terminations
Sec.  1910.307, except as specified in Sec.  1910.307(b)--Hazardous 
(classified) locations

    (2) Requirements applicable to installations made after March 15, 
1972. Every electrical installation and all utilization equipment 
installed or overhauled after March 15, 1972, shall comply with the 
provisions of Sec. Sec.  1910.302 through 1910.308, except as noted in 
paragraphs (b)(3) and (b)(4) of this section.
    (3) Requirements applicable only to installations made after April 
16, 1981. The following requirements apply only to electrical 
installations and utilization equipment installed after April 16, 1981:

Sec.  1910.303(h)(4)--Over 600 volts, nominal--Entrance and access to 
work space
Sec.  1910.304(f)(1)(vii) and (f)(1)(viii)--Overcurrent protection--600 
volts, nominal, or less
Sec.  1910.304(g)(9)(i)--Grounding--Grounding of systems and circuits 
of 1000 volts and over (high voltage)
Sec.  1910.305(j)(6)(ii)(D)--Equipment for general use--Capacitors
Sec.  1910.306(c)(9)--Elevators, dumbwaiters, escalators, moving walks, 
wheelchair lifts, and stairway chair lifts--Interconnection between 
multicar controllers
Sec.  1910.306(i)--Electrically driven or controlled irrigation 
machines
Sec.  1910.306(j)(5)--Swimming pools, fountains, and similar 
installations--Fountains
Sec.  1910.308(a)(1)(ii)--Systems over 600 volts, nominal--Aboveground 
wiring methods
Sec.  1910.308(c)(2)--Class 1, Class 2, and Class 3 remote control, 
signaling, and power-limited circuits--Marking
Sec.  1910.308(d)--Fire alarm systems

    (4) Requirements applicable only to installations made after August 
13, 2007. The following requirements apply only to electrical 
installations and utilization equipment installed after August 13, 
2007:

Sec.  1910.303(f)(4)--Disconnecting means and circuits--Capable of 
accepting a lock
Sec.  1910.303(f)(5)--Disconnecting means and circuits--Marking for 
series combination ratings
Sec.  1910.303(g)(1)(iv) and (g)(1)(vii)--600 Volts, nominal, or less--
Space about electric equipment
Sec.  1910.303(h)(5)(vi)--Over 600 volts, nominal--Working space and 
guarding
Sec.  1910.304(b)(1)--Branch circuits--Identification of multiwire 
branch circuits
Sec.  1910.304(b)(3)(i)--Branch circuits--Ground-fault circuit 
interrupter protection for personnel
Sec.  1910.304(f)(2)(i)(A), (f)(2)(i)(B) (but not the introductory text 
to Sec.  1910.304(f)(2)(i)), and (f)(2)(iv)(A)--Overcurrent 
protection--Feeders and branch circuits over 600 volts, nominal
Sec.  1910.305(c)(3)(ii)--Switches--Connection of switches
Sec.  1910.305(c)(5)--Switches--Grounding
Sec.  1910.306(a)(1)(ii)--Electric signs and outline lighting--
Disconnecting means
Sec.  1910.306(c)(4)--Elevators, dumbwaiters, escalators, moving walks, 
wheelchair lifts, and stairway chair lifts--Operation
Sec.  1910.306(c)(5)--Elevators, dumbwaiters, escalators, moving walks, 
wheelchair lifts, and stairway chair lifts--Location
Sec.  1910.306(c)(6)--Elevators, dumbwaiters, escalators, moving walks, 
wheelchair lifts, and stairway chair lifts--Identification and signs
Sec.  1910.306(c)(7)--Elevators, dumbwaiters, escalators, moving walks, 
wheelchair lifts, and stairway chair lifts--Single-car and multicar 
installations
Sec.  1910.306(j)(1)(iii)--Swimming pools, fountains, and similar 
installations--Receptacles
Sec.  1910.306(k)--Carnivals, circuses, fairs, and similar events
Sec.  1910.308(a)(5)(v) and (a)(5)(vi)(B)--Systems over 600 volts, 
nominal--Interrupting and isolating devices
Sec.  1910.308(a)(7)(vi)--Systems over 600 volts, nominal--Tunnel 
installations
Sec.  1910.308(b)(3)--Emergency power systems--Signs
Sec.  1910.308(c)(3)--Class 1, Class 2, and Class 3 remote control, 
signaling, and power-limited circuits--Separation from conductors of 
other circuits
Sec.  1910.308(f)--Solar photovoltaic systems

    (c) Applicability of requirements for disconnecting means. The 
requirement in Sec.  1910.147(c)(2)(iii) that energy isolating devices 
be capable of accepting a lockout device whenever replacement or major 
repair, renovation or modification of a machine or equipment is 
performed, and whenever new machines or equipment are installed after 
January 2, 1990, applies in addition to any requirements in Sec.  
1910.303 through Sec.  1910.308 that disconnecting means be capable of 
being locked in the open position under certain conditions.

Sec.  1910.303  General.

    (a) Approval. The conductors and equipment required or permitted by 
this subpart shall be acceptable only if approved, as defined in Sec.  
1910.399.
    (b) Examination, installation, and use of equipment--(1) 
Examination. Electric equipment shall be free from recognized hazards 
that are likely to cause death or serious physical harm to employees. 
Safety of equipment shall be determined using the following 
considerations:
    (i) Suitability for installation and use in conformity with the 
provisions of this subpart;

    Note to paragraph (b)(1)(i) of this section: Suitability of 
equipment for an identified purpose may be evidenced by listing or 
labeling for that identified purpose.

    (ii) Mechanical strength and durability, including, for parts 
designed to enclose and protect other equipment, the adequacy of the 
protection thus provided;
    (iii) Wire-bending and connection space;
    (iv) Electrical insulation;
    (v) Heating effects under all conditions of use;
    (vi) Arcing effects;
    (vii) Classification by type, size, voltage, current capacity, and 
specific use; and
    (viii) Other factors that contribute to the practical safeguarding 
of persons using or likely to come in contact with the equipment.
    (2) Installation and use. Listed or labeled equipment shall be 
installed and used in accordance with any instructions included in the 
listing or labeling.
    (3) Insulation integrity. Completed wiring installations shall be 
free from short circuits and from grounds other than those required or 
permitted by this subpart.
    (4) Interrupting rating. Equipment intended to interrupt current at 
fault levels shall have an interrupting rating sufficient for the 
nominal circuit voltage and the current that is available at the line 
terminals of the equipment. Equipment intended to interrupt current at 
other than fault levels shall have an interrupting rating at nominal 
circuit voltage sufficient for the current that must be interrupted.
    (5) Circuit impedance and other characteristics. The overcurrent 
protective devices, the total impedance, the component short-circuit 
current ratings, and other characteristics of the circuit to be protected 
shall be selected and coordinated to permit the circuit protective devices 
used to clear a fault to do so without the occurrence of extensive damage 
to the electrical components of the circuit. This fault shall be assumed 
to be either between two or more of the circuit conductors, or between 
any circuit conductor and the grounding conductor or enclosing metal raceway.
    (6) Deteriorating agents. Unless identified for use in the 
operating environment, no conductors or equipment shall be located in 
damp or wet locations; where exposed to gases, fumes, vapors, liquids, 
or other agents that have a deteriorating effect on the conductors or 
equipment; or where exposed to excessive temperatures.
    (7) Mechanical execution of work. Electric equipment shall be 
installed in a neat and workmanlike manner.
    (i) Unused openings in boxes, raceways, auxiliary gutters, 
cabinets, equipment cases, or housings shall be effectively closed to 
afford protection substantially equivalent to the wall of the 
equipment.
    (ii) Conductors shall be racked to provide ready and safe access in 
underground and subsurface enclosures that persons enter for 
installation and maintenance.
    (iii) Internal parts of electrical equipment, including busbars, 
wiring terminals, insulators, and other surfaces, may not be damaged or 
contaminated by foreign materials such as paint, plaster, cleaners, 
abrasives, or corrosive residues.
    (iv) There shall be no damaged parts that may adversely affect safe 
operation or mechanical strength of the equipment, such as parts that 
are broken, bent, cut, or deteriorated by corrosion, chemical action, 
or overheating.
    (8) Mounting and cooling of equipment. (i) Electric equipment shall 
be firmly secured to the surface on which it is mounted.


    Note to paragraph (b)(8)(i) of this section: Wooden plugs driven 
into holes in masonry, concrete, plaster, or similar materials are 
not considered secure means of fastening electric equipment.


    (ii) Electric equipment that depends on the natural circulation of 
air and convection principles for cooling of exposed surfaces shall be 
installed so that room airflow over such surfaces is not prevented by 
walls or by adjacent installed equipment. For equipment designed for 
floor mounting, clearance between top surfaces and adjacent surfaces 
shall be provided to dissipate rising warm air.
    (iii) Electric equipment provided with ventilating openings shall 
be installed so that walls or other obstructions do not prevent the 
free circulation of air through the equipment.
    (c) Electrical connections--(1) General. Because of different 
characteristics of dissimilar metals:
    (i) Devices such as pressure terminal or pressure splicing 
connectors and soldering lugs shall be identified for the material of 
the conductor and shall be properly installed and used;
    (ii) Conductors of dissimilar metals may not be intermixed in a 
terminal or splicing connector where physical contact occurs between 
dissimilar conductors (such as copper and aluminum, copper and copper-
clad aluminum, or aluminum and copper-clad aluminum) unless the device 
is identified for the purpose and conditions of use; and
    (iii) Materials such as solder, fluxes, inhibitors, and compounds, 
where employed, shall be suitable for the use and shall be of a type 
that will not adversely affect the conductors, installation, or 
equipment.
    (2) Terminals. (i) Connection of conductors to terminal parts shall 
ensure a good connection without damaging the conductors and shall be 
made by means of pressure connectors (including set-screw type), solder 
lugs, or splices to flexible leads. However, No. 10 or smaller 
conductors may be connected by means of wire binding screws or studs 
and nuts having upturned lugs or equivalent.
    (ii) Terminals for more than one conductor and terminals used to 
connect aluminum shall be so identified.
    (3) Splices. (i) Conductors shall be spliced or joined with 
splicing devices identified for the use or by brazing, welding, or 
soldering with a fusible metal or alloy. Soldered splices shall first 
be spliced or joined to be mechanically and electrically secure without 
solder and then soldered. All splices and joints and the free ends of 
conductors shall be covered with an insulation equivalent to that of 
the conductors or with an insulating device identified for the purpose.
    (ii) Wire connectors or splicing means installed on conductors for 
direct burial shall be listed for such use.
    (d) Arcing parts. Parts of electric equipment that in ordinary 
operation produce arcs, sparks, flames, or molten metal shall be 
enclosed or separated and isolated from all combustible material.
    (e) Marking--(1) Identification of manufacturer and ratings. 
Electric equipment may not be used unless the following markings have 
been placed on the equipment:
    (i) The manufacturer's name, trademark, or other descriptive 
marking by which the organization responsible for the product may be 
identified; and
    (ii) Other markings giving voltage, current, wattage, or other 
ratings as necessary.
    (2) Durability. The marking shall be of sufficient durability to 
withstand the environment involved.
    (f) Disconnecting means and circuits--(1) Motors and appliances. 
Each disconnecting means required by this subpart for motors and 
appliances shall be legibly marked to indicate its purpose, unless 
located and arranged so the purpose is evident.
    (2) Services, feeders, and branch circuits. Each service, feeder, 
and branch circuit, at its disconnecting means or overcurrent device, 
shall be legibly marked to indicate its purpose, unless located and 
arranged so the purpose is evident.
    (3) Durability of markings. The markings required by paragraphs 
(f)(1) and (f)(2) of this section shall be of sufficient durability to 
withstand the environment involved.
    (4) Capable of accepting a lock. Disconnecting means required by 
this subpart shall be capable of being locked in the open position.
    (5) Marking for series combination ratings. (i) Where circuit 
breakers or fuses are applied in compliance with the series combination 
ratings marked on the equipment by the manufacturer, the equipment 
enclosures shall be legibly marked in the field to indicate that the 
equipment has been applied with a series combination rating.
    (ii) The marking required by paragraph (f)(5)(i) of this section 
shall be readily visible and shall state "Caution--Series Combination 
System Rated ---- Amperes. Identified Replacement Component Required."
    (g) 600 Volts, nominal, or less. This paragraph applies to electric 
equipment operating at 600 volts, nominal, or less to ground.
    (1) Space about electric equipment. Sufficient access and working 
space shall be provided and maintained about all electric equipment to 
permit ready and safe operation and maintenance of such equipment.
    (i) Working space for equipment likely to require examination, 
adjustment, servicing, or maintenance while energized shall comply with 
the following dimensions, except as required or permitted elsewhere in 
this subpart:
    (A) The depth of the working space in the direction of access to 
live parts may not be less than indicated in Table S-1. Distances shall 
be measured from the live parts if they are exposed or from the 
enclosure front or opening if they are enclosed;
    (B) The width of working space in front of the electric equipment 
shall be the width of the equipment or 762 mm (30 in.), whichever is 
greater. In all cases, the working space shall permit at least a 90-
degree opening of equipment doors or hinged panels; and
    (C) The work space shall be clear and extend from the grade, floor, 
or platform to the height required by paragraph (g)(1)(vi) of this 
section. However, other equipment associated with the electrical 
installation and located above or below the electric equipment may 
extend not more than 153 mm (6 in.) beyond the front of the electric 
equipment.
    (ii) Working space required by this standard may not be used for 
storage. When normally enclosed live parts are exposed for inspection 
or servicing, the working space, if in a passageway or general open 
space, shall be suitably guarded.
    (iii) At least one entrance of sufficient area shall be provided to 
give access to the working space about electric equipment.
    (iv) For equipment rated 1200 amperes or more and over 1.83 m (6.0 
ft) wide, containing overcurrent devices, switching devices, or control 
devices, there shall be one entrance not less than 610 mm (24 in.) wide 
and 1.98 m (6.5 ft) high at each end of the working space, except that:
    (A) Where the location permits a continuous and unobstructed way of 
exit travel, one means of exit is permitted; or
    (B) Where the working space required by paragraph (g)(1)(i) of this 
section is doubled, only one entrance to the working space is required; 
however, the entrance shall be located so that the edge of the entrance 
nearest the equipment is the minimum clear distance given in Table S-1 
away from such equipment.
    (v) Illumination shall be provided for all working spaces about 
service equipment, switchboards, panelboards, and motor control centers 
installed indoors. Additional lighting fixtures are not required where 
the working space is illuminated by an adjacent light source. In 
electric equipment rooms, the illumination may not be controlled by 
automatic means only.
    (vi) The minimum headroom of working spaces about service 
equipment, switchboards, panelboards, or motor control centers shall be 
as follows:
    (A) For installations built before August 13, 2007, 1.91 m (6.25 
ft); and
    (B) For installations built on or after August 13, 2007, 1.98 m 
(6.5 ft), except that where the electrical equipment exceeds 1.98 m 
(6.5 ft) in height, the minimum headroom may not be less than the 
height of the equipment.

              Table S-1.--Minimum Depth of Clear Working Space at Electric Equipment, 600 V or Less
----------------------------------------------------------------------------------------------------------------
                                                          Minimum clear distance for condition \2\ \3\
                                               -----------------------------------------------------------------
           Nominal voltage to ground                 Condition A           Condition B           Condition C
                                               -----------------------------------------------------------------
                                                    m          ft         m          ft         m          ft
----------------------------------------------------------------------------------------------------------------
0-150.........................................     \1\0.9     \1\3.0     \1\0.9     \1\3.0        0.9        3.0
151-600.......................................     \1\0.9     \1\3.0        1.0        3.5        1.2       4.0
----------------------------------------------------------------------------------------------------------------
 Notes to Table S-1:
 1. Minimum clear distances may be 0.7 m (2.5 ft) for installations built before April 16, 1981.
 2. Conditions A, B, and C are as follows:
 Condition A--Exposed live parts on one side and no live or grounded parts on the other side of the working
  space, or exposed live parts on both sides effectively guarded by suitable wood or other insulating material.
  Insulated wire or insulated busbars operating at not over 300 volts are not considered live parts.
 Condition B--Exposed live parts on one side and grounded parts on the other side.
 Condition C--Exposed live parts on both sides of the work space (not guarded as provided in Condition A) with
  the operator between.
 3. Working space is not required in back of assemblies such as dead-front switchboards or motor control centers
  where there are no renewable or adjustable parts (such as fuses or switches) on the back and where all
  connections are accessible from locations other than the back. Where rear access is required to work on
  deenergized parts on the back of enclosed equipment, a minimum working space of 762 mm (30 in.) horizontally
  shall be provided.

    (vii) Switchboards, panelboards, and distribution boards installed 
for the control of light and power circuits, and motor control centers 
shall be located in dedicated spaces and protected from damage.
    (A) For indoor installation, the dedicated space shall comply with 
the following:
    (1) The space equal to the width and depth of the equipment and 
extending from the floor to a height of 1.83 m (6.0 ft) above the 
equipment or to the structural ceiling, whichever is lower, shall be 
dedicated to the electrical installation. Unless isolated from 
equipment by height or physical enclosures or covers that will afford 
adequate mechanical protection from vehicular traffic or accidental 
contact by unauthorized personnel or that complies with paragraph 
(g)(1)(vii)(A)(2) of this section, piping, ducts, or equipment foreign 
to the electrical installation may not be located in this area;
    (2) The space equal to the width and depth of the equipment shall 
be kept clear of foreign systems unless protection is provided to avoid 
damage from condensation, leaks, or breaks in such foreign systems. 
This area shall extend from the top of the electric equipment to the 
structural ceiling;
    (3) Sprinkler protection is permitted for the dedicated space where 
the piping complies with this section; and
    (4) Control equipment that by its very nature or because of other 
requirements in this subpart must be adjacent to or within sight of its 
operating machinery is permitted in the dedicated space.

    Note to paragraph (g)(1)(vii)(A) of this section: A dropped, 
suspended, or similar ceiling that does not add strength to the 
building structure is not considered a structural ceiling.

    (B) Outdoor electric equipment shall be installed in suitable 
enclosures and shall be protected from accidental contact by 
unauthorized personnel, or by vehicular traffic, or by accidental 
spillage or leakage from piping systems. No architectural appurtenance 
or other equipment may be located in the working space required by 
paragraph (g)(1)(i) of this section.
    (2) Guarding of live parts. (i) Except as elsewhere required or 
permitted by this standard, live parts of electric equipment operating 
at 50 volts or more shall be guarded against accidental
contact by use of approved cabinets or other forms of approved 
enclosures or by any of the following means:
    (A) By location in a room, vault, or similar enclosure that is 
accessible only to qualified persons;
    (B) By suitable permanent, substantial partitions or screens so 
arranged so that only qualified persons will have access to the space 
within reach of the live parts. Any openings in such partitions or 
screens shall be so sized and located that persons are not likely to 
come into accidental contact with the live parts or to bring conducting 
objects into contact with them;
    (C) By placement on a suitable balcony, gallery, or platform so 
elevated and otherwise located as to prevent access by unqualified 
persons; or
    (D) By elevation of 2.44 m (8.0 ft) or more above the floor or 
other working surface.
    (ii) In locations where electric equipment is likely to be exposed 
to physical damage, enclosures or guards shall be so arranged and of 
such strength as to prevent such damage.
    (iii) Entrances to rooms and other guarded locations containing 
exposed live parts shall be marked with conspicuous warning signs 
forbidding unqualified persons to enter.
    (h) Over 600 volts, nominal--(1) General. Conductors and equipment 
used on circuits exceeding 600 volts, nominal, shall comply with all 
applicable provisions of the paragraphs (a) through (g) of this section 
and with the following provisions, which supplement or modify the 
preceding requirements. However, paragraphs (h)(2), (h)(3), and (h)(4) 
of this section do not apply to the equipment on the supply side of the 
service point.
    (2) Enclosure for electrical installations. (i) Electrical 
installations in a vault, room, or closet or in an area surrounded by a 
wall, screen, or fence, access to which is controlled by lock and key 
or other approved means, are considered to be accessible to qualified 
persons only. The type of enclosure used in a given case shall be 
designed and constructed according to the hazards associated with the 
installation.
    (ii) For installations other than equipment described in paragraph 
(h)(2)(v) of this section, a wall, screen, or fence shall be used to 
enclose an outdoor electrical installation to deter access by persons 
who are not qualified. A fence may not be less than 2.13 m (7.0 ft) in 
height or a combination of 1.80 m (6.0 ft) or more of fence fabric and 
a 305-mm (1-ft) or more extension utilizing three or more strands of 
barbed wire or equivalent.
    (iii) The following requirements apply to indoor installations that 
are accessible to other than qualified persons:
    (A) The installations shall be made with metal-enclosed equipment 
or shall be enclosed in a vault or in an area to which access is 
controlled by a lock;
    (B) Metal-enclosed switchgear, unit substations, transformers, pull 
boxes, connection boxes, and other similar associated equipment shall 
be marked with appropriate caution signs; and
    (C) Openings in ventilated dry-type transformers and similar 
openings in other equipment shall be designed so that foreign objects 
inserted through these openings will be deflected from energized parts.
    (iv) Outdoor electrical installations having exposed live parts 
shall be accessible to qualified persons only.
    (v) The following requirements apply to outdoor enclosed equipment 
accessible to unqualified employees:
    (A) Ventilating or similar openings in equipment shall be so 
designed that foreign objects inserted through these openings will be 
deflected from energized parts;
    (B) Where exposed to physical damage from vehicular traffic, 
suitable guards shall be provided;
    (C) Nonmetallic or metal-enclosed equipment located outdoors and 
accessible to the general public shall be designed so that exposed nuts 
or bolts cannot be readily removed, permitting access to live parts;
    (D) Where nonmetallic or metal-enclosed equipment is accessible to 
the general public and the bottom of the enclosure is less than 2.44 m 
(8.0 ft) above the floor or grade level, the enclosure door or hinged 
cover shall be kept locked; and
    (E) Except for underground box covers that weigh over 45.4 kg (100 
lb), doors and covers of enclosures used solely as pull boxes, splice 
boxes, or junction boxes shall be locked, bolted, or screwed on.
    (3) Work space about equipment. Sufficient space shall be provided 
and maintained about electric equipment to permit ready and safe 
operation and maintenance of such equipment. Where energized parts are 
exposed, the minimum clear work space may not be less than 1.98 m (6.5 
ft) high (measured vertically from the floor or platform) or less than 
914 mm (3.0 ft) wide (measured parallel to the equipment). The depth 
shall be as required in paragraph (h)(5)(i) of this section. In all 
cases, the work space shall be adequate to permit at least a 90-degree 
opening of doors or hinged panels.
    (4) Entrance and access to work space. (i) At least one entrance 
not less than 610 mm (24 in.) wide and 1.98 m (6.5 ft) high shall be 
provided to give access to the working space about electric equipment.
    (A) On switchboard and control panels exceeding 1.83 m (6.0 ft) in 
width, there shall be one entrance at each end of such boards unless 
the location of the switchboards and control panels permits a 
continuous and unobstructed way of exit travel, or unless the work 
space required in paragraph (h)(5)(i) of this section is doubled.
    (B) Where one entrance to the working space is permitted under the 
conditions described in paragraph (h)(4)(i)(A) of this section, the 
entrance shall be located so that the edge of the entrance nearest the 
switchboards and control panels is at least the minimum clear distance 
given in Table S-2 away from such equipment.
    (C) Where bare energized parts at any voltage or insulated 
energized parts above 600 volts, nominal, to ground are located 
adjacent to such entrance, they shall be suitably guarded.
    (ii) Permanent ladders or stairways shall be provided to give safe 
access to the working space around electric equipment installed on 
platforms, balconies, mezzanine floors, or in attic or roof rooms or 
spaces.
    (5) Working space and guarding. (i)(vi) Except as elsewhere 
required or permitted in this subpart, the minimum clear working space 
in the direction of access to live parts of electric equipment may not 
be less than specified in Table S-2. Distances shall be measured from 
the live parts, if they are exposed, or from the enclosure front or 
opening, if they are enclosed.
    (ii) If switches, cutouts, or other equipment operating at 600 
volts, nominal, or less, are installed in a room or enclosure where 
there are exposed live parts or exposed wiring operating at over 600 
volts, nominal, the high-voltage equipment shall be effectively 
separated from the space occupied by the low-voltage equipment by a 
suitable partition, fence, or screen. However, switches or other 
equipment operating at 600 volts, nominal, or less, and serving only 
equipment within the high-voltage vault, room, or enclosure may be 
installed in the high-voltage enclosure, room, or vault if accessible 
to qualified persons only.
    (iii) The following requirements apply to the entrances to all 
buildings, rooms, or enclosures containing exposed live parts or 
exposed conductors operating at over 600 volts, nominal:
    (A) The entrances shall be kept locked unless they are under the 
observation of a qualified person at all times; and
    (B) Permanent and conspicuous warning signs shall be provided, 
reading substantially as follows:
"DANGER--HIGH VOLTAGE--KEEP OUT."
    (iv) Illumination shall be provided for all working spaces about 
electric equipment.
    (A) The lighting outlets shall be arranged so that persons changing 
lamps or making repairs on the lighting system will not be endangered 
by live parts or other equipment.
    (B) The points of control shall be located so that persons are 
prevented from contacting any live part or moving part of the equipment 
while turning on the lights.
    (v) Unguarded live parts above working space shall be maintained at 
elevations not less than specified in Table S-3.
    (vi) Pipes or ducts that are foreign to the electrical installation 
and that require periodic maintenance or whose malfunction would 
endanger the operation of the electrical system may not be located in 
the vicinity of service equipment, metal-enclosed power switchgear, or 
industrial control assemblies. Protection shall be provided where 
necessary to avoid damage from condensation leaks and breaks in such 
foreign systems.

    Note to paragraph (h)(5)(vi) of this section: Piping and other 
facilities are not considered foreign if provided for fire 
protection of the electrical installation.


               Table S-2.--Minimum Depth of Clear Working Space at Electric Equipment, Over 600 V
----------------------------------------------------------------------------------------------------------------
                                                          Minimum clear distance for condition \2\ \3\
                                               -----------------------------------------------------------------
           Nominal voltage to ground                 Condition A           Condition B           Condition C
                                               -----------------------------------------------------------------
                                                    m          ft         m          ft         m          ft
----------------------------------------------------------------------------------------------------------------
601-2500 V....................................        0.9        3.0        1.2        4.0        1.5        5.0
2501-9000 V...................................        1.2        4.0        1.5        5.0        1.8        6.0
9001 V-25 kV..................................        1.5        5.0        1.8        6.0        2.8        9.0
Over 25-75 kV \1\.............................        1.8        6.0        2.5        8.0        3.0       10.0
Above 75 kV \1\...............................        2.5        8.0        3.0       10.0        3.7      12.0
----------------------------------------------------------------------------------------------------------------
Notes to Table S-2:
\1\ Minimum depth of clear working space in front of electric equipment with a nominal voltage to ground above
  25,000 volts may be the same as that for 25,000 volts under Conditions A, B, and C for installations built
  before April 16, 1981.
\2\ Conditions A, B, and C are as follows:
Condition A--Exposed live parts on one side and no live or grounded parts on the other side of the working
  space, or exposed live parts on both sides effectively guarded by suitable wood or other insulating material.
  Insulated wire or insulated busbars operating at not over 300 volts are not considered live parts.
Condition B--Exposed live parts on one side and grounded parts on the other side. Concrete, brick, and tile
  walls are considered as grounded surfaces.
Condition C--Exposed live parts on both sides of the work space (not guarded as provided in Condition A) with
  the operator between.
\3\ Working space is not required in back of equipment such as dead-front switchboards or control assemblies
  that has no renewable or adjustable parts (such as fuses or switches) on the back and where all connections
  are accessible from locations other than the back. Where rear access is required to work on the deenergized
  parts on the back of enclosed equipment, a minimum working space 762 mm (30 in.) horizontally shall be
  provided.


    Table S-3.--Elevation of Unguarded Live Parts Above Working Space
------------------------------------------------------------------------
                                                 Elevation
 Nominal voltage between phases  ---------------------------------------
                                           m                  ft
------------------------------------------------------------------------
601-7500 V......................  \1\ 2.81..........  \1\ 9.01.
7501 V-35 kV....................  2.8...............  9.0.
Over 35 kV......................  2.8 + 9.5 mm/kV     9.0 + 0.37 in./kV
                                   over 35 kV.         over 35 kV.
------------------------------------------------------------------------
\1\ The minimum elevation may be 2.6 m (8.5 ft) for installations built
  before August 13, 2007. The minimum elevation may be 2.4 m (8.0 ft)
  for installations built before April 16, 1981, if the nominal voltage
  between phases is in the range of 601-6600 volts.

Sec.  1910.304  Wiring design and protection.

    (a) Use and identification of grounded and grounding conductors--
(1) Identification of conductors. (i) A conductor used as a grounded 
conductor shall be identifiable and distinguishable from all other 
conductors.
    (ii) A conductor used as an equipment grounding conductor shall be 
identifiable and distinguishable from all other conductors.
    (2) Polarity of connections. No grounded conductor may be attached 
to any terminal or lead so as to reverse designated polarity.
    (3) Use of grounding terminals and devices. A grounding terminal or 
grounding-type device on a receptacle, cord connector, or attachment 
plug may not be used for purposes other than grounding.
    (b) Branch circuits--(1) Identification of multiwire branch 
circuits. Where more than one nominal voltage system exists in a 
building containing multiwire branch circuits, each ungrounded 
conductor of a multiwire branch circuit, where accessible, shall be 
identified by phase and system. The means of identification shall be 
permanently posted at each branch-circuit panelboard.
    (2) Receptacles and cord connectors. (i) Receptacles installed on 
15- and 20-ampere branch circuits shall be of the grounding type except 
as permitted for replacement receptacles in paragraph (b)(2)(iv) of 
this section. Grounding-type receptacles shall be installed only on 
circuits of the voltage class and current for which they are rated, 
except as provided in Table S-4 and Table S-5.
    (ii) Receptacles and cord connectors having grounding contacts 
shall have those contacts effectively grounded except for receptacles 
mounted on portable and vehicle-mounted generators in accordance with 
paragraph (g)(3) of this section and replacement receptacles installed 
in accordance with paragraph (b)(2)(iv) of this section.
    (iii) The grounding contacts of receptacles and cord connectors 
shall be grounded by connection to the equipment grounding conductor of 
the circuit supplying the receptacle or cord connector. The branch 
circuit wiring method shall include or provide an equipment grounding 
conductor to which the grounding contacts of the receptacle or cord 
connector shall be connected.
    (iv) Replacement of receptacles shall comply with the following 
requirements:
    (A) Where a grounding means exists in the receptacle enclosure or a 
grounding conductor is installed, grounding-type receptacles shall be 
used and shall be connected to the grounding means or conductor;
    (B) Ground-fault circuit-interrupter protected receptacles shall be 
provided where replacements are made at receptacle outlets that are 
required to be so protected elsewhere in this subpart; and
    (C) Where a grounding means does not exist in the receptacle 
enclosure, the installation shall comply with one of the following 
provisions:
    (1) A nongrounding-type receptacle may be replaced with another 
nongrounding-type receptacle; or
    (2) A nongrounding-type receptacle may be replaced with a ground-
fault circuit-interrupter-type of receptacle that is marked "No 
Equipment Ground;" an equipment grounding conductor may not be 
connected from the ground-fault circuit-interrupter-type receptacle to 
any outlet supplied from the ground-fault circuit-interrupter 
receptacle; or
    (3) A nongrounding-type receptacle may be replaced with a 
grounding-type receptacle where supplied through a ground-fault 
circuit-interrupter; the replacement receptacle shall be marked "GFCI 
Protected" and "No Equipment Ground;" an equipment grounding 
conductor may not be connected to such grounding-type receptacles.
    (v) Receptacles connected to circuits having different voltages, 
frequencies, or types of current (ac or dc) on the same premises shall 
be of such design that the attachment plugs used on these circuits are 
not interchangeable.
    (3) Ground-fault circuit interrupter protection for personnel. (i) 
All 125-volt, single-phase, 15- and 20-ampere receptacles installed in 
bathrooms or on rooftops shall have ground-fault circuit-interrupter 
protection for personnel.
    (ii) The following requirements apply to temporary wiring 
installations that are used during maintenance, remodeling, or repair 
of buildings, structures, or equipment or during similar construction-
like activities.
    (A) All 125-volt, single-phase, 15-, 20-, and 30-ampere receptacle 
outlets that are not part of the permanent wiring of the building or 
structure and that are in use by personnel shall have ground-fault 
circuit-interrupter protection for personnel.

    Note 1 to paragraph (b)(3)(ii)(A) of this section: A cord 
connector on an extension cord set is considered to be a receptacle 
outlet if the cord set is used for temporary electric power.

    Note 2 to paragraph (b)(3)(ii)(A) of this section: Cord sets and 
devices incorporating the required ground-fault circuit-interrupter 
that are connected to the receptacle closest to the source of power 
are acceptable forms of protection.

    (B) Receptacles other than 125 volt, single-phase, 15-, 20-, and 
30-ampere receptacles that are not part of the permanent wiring of the 
building or structure and that are in use by personnel shall have 
ground-fault circuit-interrupter protection for personnel.
    (C) Where the ground-fault circuit-interrupter protection required 
by paragraph (b)(3)(ii)(B) of this section is not available for 
receptacles other than 125-volt, single-phase, 15-, 20-, and 30-ampere, 
the employer shall establish and implement an assured equipment 
grounding conductor program covering cord sets, receptacles that are 
not a part of the building or structure, and equipment connected by 
cord and plug that are available for use or used by employees on those 
receptacles. This program shall comply with the following requirements:
    (1) A written description of the program, including the specific 
procedures adopted by the employer, shall be available at the jobsite 
for inspection and copying by the Assistant Secretary of Labor and any 
affected employee;
    (2) The employer shall designate one or more competent persons to 
implement the program;
    (3) Each cord set, attachment cap, plug, and receptacle of cord 
sets, and any equipment connected by cord and plug, except cord sets 
and receptacles which are fixed and not exposed to damage, shall be 
visually inspected before each day's use for external defects, such as 
deformed or missing pins or insulation damage, and for indications of 
possible internal damage. Equipment found damaged or defective shall 
not be used until repaired;
    (4) The following tests shall be performed on all cord sets and 
receptacles which are not a part of the permanent wiring of the 
building or structure, and cord- and plug-connected equipment required 
to be grounded:
    (i) All equipment grounding conductors shall be tested for 
continuity and shall be electrically continuous;
    (ii) Each receptacle and attachment cap or plug shall be tested for 
correct attachment of the equipment grounding conductor. The equipment 
grounding conductor shall be connected to its proper terminal; and
    (iii) All required tests shall be performed before first use; 
before equipment is returned to service following any repairs; before 
equipment is used after any incident which can be reasonably suspected 
to have caused damage (for example, when a cord set is run over); and 
at intervals not to exceed 3 months, except that cord sets and 
receptacles which are fixed and not exposed to damage shall be tested 
at intervals not exceeding 6 months;
    (5) The employer shall not make available or permit the use by 
employees of any equipment which has not met the requirements of 
paragraph (b)(3)(ii)(C) of this section; and
    (6) Tests performed as required in paragraph (b)(3)(ii)(C) of this 
section shall be recorded. This test record shall identify each 
receptacle, cord set, and cord- and plug-connected equipment that 
passed the test and shall indicate the last date it was tested or the 
interval for which it was tested. This record shall be kept by means of 
logs, color coding, or other effective means and shall be maintained 
until replaced by a more current record. The record shall be made 
available on the jobsite for inspection by the Assistant Secretary and 
any affected employee.
    (4) Outlet devices. Outlet devices shall have an ampere rating not 
less than the load to be served and shall comply with the following 
provisions:
    (i) Where connected to a branch circuit having a rating in excess 
of 20 amperes, lampholders shall be of the heavy-duty type. A heavy-
duty lampholder shall have a rating of not less than 660 watts if of 
the admedium type and not less than 750 watts if of any other type; and
    (ii) Receptacle outlets shall comply with the following provisions:
    (A) A single receptacle installed on an individual branch circuit 
shall have an ampere rating of not less than that of the branch 
circuit;
    (B) Where connected to a branch circuit supplying two or more 
receptacles or outlets, a receptacle may not supply a total cord- and 
plug-connected load in excess of the maximum specified in Table S-4; 
and
    (C) Where connected to a branch circuit supplying two or more 
receptacles or outlets, receptacle ratings shall conform to the values 
listed in Table S-5; or, where larger than 50 amperes, the receptacle 
rating may not be less than the branch-circuit rating. However, 
receptacles of cord- and plug-connected arc welders may have ampere 
ratings not less than the minimum branch-circuit conductor ampacity.
    (5) Cord connections. A receptacle outlet shall be installed 
wherever flexible cords with attachment plugs are used. Where flexible 
cords are permitted to be permanently connected, receptacles may be 
omitted.

     Table S-4.--Maximum Cord- and Plug-Connected Load to Receptacle
------------------------------------------------------------------------
                                                 Receptacle    Maximum
           Circuit rating  (amperes)               rating        load
                                                 (amperes)    (amperes)
------------------------------------------------------------------------
15 or 20......................................           15           12
20............................................           20           16
30............................................           30           24
------------------------------------------------------------------------


        Table S-5.--Receptacle Ratings for Various Size Circuits
------------------------------------------------------------------------
         Circuit rating  (amperes)          Receptacle rating  (amperes)
------------------------------------------------------------------------
15........................................  Not over 15.
20........................................  15 or 20.
30........................................  30.
40........................................  40 or 50.
50........................................  50.
------------------------------------------------------------------------

    (c) Outside conductors, 600 volts, nominal, or less. The following 
requirements apply to branch-circuit, feeder, and service conductors 
rated 600 volts, nominal, or less and run outdoors as open conductors.
    (1) Conductors on poles. Conductors on poles shall have a 
separation of not less than 305 mm (1.0 ft) where not placed on racks 
or brackets. Conductors supported on poles shall provide a horizontal 
climbing space not less than the following:
    (i) Power conductors below communication conductors--762 mm (30 
in.);
    (ii) Power conductors alone or above communication conductors:
    (A) 300 volts or less--610 mm (24 in.),
    (B) Over 300 volts--762 mm (30 in.);
    (iii) Communication conductors below power conductors--same as 
power conductors; and
    (iv) Communications conductors alone--no requirement.
    (2) Clearance from ground. Open conductors, open multiconductor 
cables, and service-drop conductors of not over 600 volts, nominal, 
shall conform to the minimum clearances specified in Table S-6.

                                       Table S-66.--Clearances From Ground
----------------------------------------------------------------------------------------------------------------
                                     Installations built before August 13,     Installations built on or after
                                                      2007                             August 13, 2007
              Distance              ----------------------------------------------------------------------------
                                       Maximum voltage       Conditions      Voltage to ground     Conditions
----------------------------------------------------------------------------------------------------------------
3.05 m (10.0 ft)...................  <  600 V...........  Above finished     <  150 V...........  Above finished
                                                          grade or                               grade or
                                                          sidewalks, or                          sidewalks, or
                                                          from any                               from any
                                                          platform or                            platform or
                                                          projection from                        projection from
                                                          which they might                       which they
                                                          be reached. (If                        might be
                                                          these areas are                        reached. (If
                                                          accessible to                          these areas are
                                                          other than                             accessible to
                                                          pedestrian                             other than
                                                          traffic, then                          pedestrian
                                                          one of the other                       traffic, then
                                                          conditions                             one of the
                                                          applies).                              other
                                                                                                 conditions
                                                                                                 applies.)
3.66 m (12.0 ft)...................  <  600 V...........  Over areas, other  <  300 V...........  Over residential
                                                          than public                            property and
                                                          streets, alleys,                       driveways. Over
                                                          roads, and                             commercial
                                                          driveways,                             areas subject
                                                          subject to                             to pedestrian
                                                          vehicular                              traffic or to
                                                          traffic other                          vehicular
                                                          than truck                             traffic other
                                                          traffic.                               than truck
                                                                                                 traffic. (This
                                                                                                 category
                                                                                                 includes
                                                                                                 conditions
                                                                                                 covered under
                                                                                                 the 3.05-m
                                                                                                 (10.0-ft)
                                                                                                 category where
                                                                                                 the voltage
                                                                                                 exceeds 150 V.)
4.57 m (15.0 ft)...................  <  600 V...........  Over areas, other  301 to 600 V......  Over residential
                                                          than public                            property and
                                                          streets, alleys,                       driveways. Over
                                                          roads, and                             commercial
                                                          driveways,                             areas subject
                                                          subject to truck                       to pedestrian
                                                          traffic.                               traffic or to
                                                                                                 vehicular
                                                                                                 traffic other
                                                                                                 than truck
                                                                                                 traffic. (This
                                                                                                 category
                                                                                                 includes
                                                                                                 conditions
                                                                                                 covered under
                                                                                                 the 3.05-m
                                                                                                 (10.0-ft)
                                                                                                 category where
                                                                                                 the voltage
                                                                                                 exceeds 300 V.)
5.49 m (18.0 ft)...................  <  600 V...........  Over public        <  600 V...........  Over public
                                                          streets, alleys,                       streets,
                                                          roads, and                             alleys, roads,
                                                          driveways.                             and driveways.
                                                                                                 Over commercial
                                                                                                 areas subject
                                                                                                 to truck
                                                                                                 traffic. Other
                                                                                                 land traversed
                                                                                                 by vehicles,
                                                                                                 including land
                                                                                                 used for
                                                                                                 cultivating or
                                                                                                 grazing and
                                                                                                 forests and
                                                                                                 orchards.
----------------------------------------------------------------------------------------------------------------

    (3) Clearance from building openings. (i) Service conductors 
installed as open conductors or multiconductor cable without an overall 
outer jacket shall have a clearance of not less than 914 mm (3.0 ft) 
from windows that are designed to be opened, doors, porches, balconies, 
ladders, stairs, fire escapes, and similar locations. However, 
conductors that run above the top level of a window may be less than 
914 mm (3.0 ft) from the window. Vertical clearance of final spans 
above, or within 914 mm (3.0 ft) measured horizontally of, platforms, 
projections, or surfaces from which they might be reached shall be 
maintained in accordance with paragraph (c)(2) of this section.
    (ii) Overhead service conductors may not be installed beneath 
openings through which materials may be moved, such as openings in farm 
and commercial buildings, and may not be installed where they will obstruct 
entrance to these building openings.
    (4) Above roofs. Overhead spans of open conductors and open 
multiconductor cables shall have a vertical clearance of not less than 
2.44 m (8.0 ft) above the roof surface. The vertical clearance above 
the roof level shall be maintained for a distance not less than 914 mm 
(3.0 ft) in all directions from the edge of the roof.
    (i) The area above a roof surface subject to pedestrian or 
vehicular traffic shall have a vertical clearance from the roof surface 
in accordance with the clearance requirements of paragraph (c)(2) of 
this section.
    (ii) A reduction in clearance to 914 mm (3.0 ft) is permitted where 
the voltage between conductors does not exceed 300 and the roof has a 
slope of 102 mm (4 in.) in 305 mm (12 in.) or greater.
    (iii) A reduction in clearance above only the overhanging portion 
of the roof to not less than 457 mm (18 in.) is permitted where the 
voltage between conductors does not exceed 300 if:
    (A) The conductors do not pass above the roof overhang for a 
distance of more than 1.83 m (6.0 ft), 1.22 m (4.0 ft) horizontally, 
and
    (B) The conductors are terminated at a through-the-roof raceway or 
approved support.
    (iv) The requirement for maintaining a vertical clearance of 914 mm 
(3.0 ft) from the edge of the roof does not apply to the final 
conductor span, where the conductors are attached to the side of a 
building.
    (d) Location of outdoor lamps. Lamps for outdoor lighting shall be 
located below all energized conductors, transformers, or other electric 
equipment, unless such equipment is controlled by a disconnecting means 
that can be locked in the open position, or unless adequate clearances 
or other safeguards are provided for relamping operations.
    (e) Services--(1) Disconnecting means. (i) Means shall be provided 
to disconnect all conductors in a building or other structure from the 
service-entrance conductors. The service disconnecting means shall 
plainly indicate whether it is in the open or closed position and shall 
be installed at a readily accessible location nearest the point of 
entrance of the service-entrance conductors.
    (ii) Each service disconnecting means shall simultaneously 
disconnect all ungrounded conductors.
    (iii) Each service disconnecting means shall be suitable for the 
prevailing conditions.
    (2) Services over 600 volts, nominal. The following additional 
requirements apply to services over 600 volts, nominal.
    (i) Service-entrance conductors installed as open wires shall be 
guarded to make them accessible only to qualified persons.
    (ii) Signs warning of high voltage shall be posted where 
unqualified employees might come in contact with live parts.
    (f) Overcurrent protection--(1) 600 volts, nominal, or less. The 
following requirements apply to overcurrent protection of circuits 
rated 600 volts, nominal, or less.
    (i) Conductors and equipment shall be protected from overcurrent in 
accordance with their ability to safely conduct current.
    (ii) Except for motor running overload protection, overcurrent 
devices may not interrupt the continuity of the grounded conductor 
unless all conductors of the circuit are opened simultaneously.
    (iii) A disconnecting means shall be provided on the supply side of 
all fuses in circuits over 150 volts to ground and cartridge fuses in 
circuits of any voltage where accessible to other than qualified 
persons so that each individual circuit containing fuses can be 
independently disconnected from the source of power. However, a 
current-limiting device without a disconnecting means is permitted on 
the supply side of the service disconnecting means. In addition, a 
single disconnecting means is permitted on the supply side of more than 
one set of fuses as permitted by the exception in Sec.  
1910.305(j)(4)(vi) for group operation of motors, and a single 
disconnecting means is permitted for fixed electric space-heating 
equipment.
    (iv) Overcurrent devices shall be readily accessible to each 
employee or authorized building management personnel. These overcurrent 
devices may not be located where they will be exposed to physical 
damage or in the vicinity of easily ignitable material.
    (v) Fuses and circuit breakers shall be so located or shielded that 
employees will not be burned or otherwise injured by their operation. 
Handles or levers of circuit breakers, and similar parts that may move 
suddenly in such a way that persons in the vicinity are likely to be 
injured by being struck by them, shall be guarded or isolated.
    (vi) Circuit breakers shall clearly indicate whether they are in 
the open (off) or closed (on) position.
    (vii) Where circuit breaker handles on switchboards are operated 
vertically rather than horizontally or rotationally, the up position of 
the handle shall be the closed (on) position.
    (viii) Circuit breakers used as switches in 120-volt and 277-volt, 
fluorescent lighting circuits shall be listed and marked "SWD."
    (ix) A circuit breaker with a straight voltage rating, such as 240 
V or 480 V, may only be installed in a circuit in which the nominal 
voltage between any two conductors does not exceed the circuit 
breaker's voltage rating. A two-pole circuit breaker may not be used 
for protecting a 3-phase, corner-grounded delta circuit unless the 
circuit breaker is marked 1[Phi]--3[Phi] to indicate such suitability. 
A circuit breaker with a slash rating, such as 120/240 V or 480Y/277 V, 
may only be installed in a circuit where the nominal voltage of any 
conductor to ground does not exceed the lower of the two values of the 
circuit breaker's voltage rating and the nominal voltage between any 
two conductors does not exceed the higher value of the circuit 
breaker's voltage rating.
    (2) Feeders and branch circuits over 600 volts, nominal. The 
following requirements apply to feeders and branch circuits energized 
at more than 600 volts, nominal:
    (i) Feeder and branch-circuit conductors shall have overcurrent 
protection in each ungrounded conductor located at the point where the 
conductor receives its supply or at a location in the circuit 
determined under engineering supervision;
    (A) Circuit breakers used for overcurrent protection of three-phase 
circuits shall have a minimum of three overcurrent relays operated from 
three current transformers. On three-phase, three-wire circuits, an 
overcurrent relay in the residual circuit of the current transformers 
may replace one of the phase relays. An overcurrent relay, operated 
from a current transformer that links all phases of a three-phase, 
three-wire circuit, may replace the residual relay and one other phase-
conductor current transformer. Where the neutral is not grounded on the 
load side of the circuit, the current transformer may link all three 
phase conductors and the grounded circuit conductor (neutral); and
    (B) If fuses are used for overcurrent protection, a fuse shall be 
connected in series with each ungrounded conductor;
    (ii) Each protective device shall be capable of detecting and 
interrupting all values of current that can occur at its location in 
excess of its trip setting or melting point;
    (iii) The operating time of the protective device, the available 
short-circuit current, and the conductor used shall be coordinated to 
prevent damaging or dangerous temperatures in conductors or conductor 
insulation under short-circuit conditions; and
    (iv) The following additional requirements apply to feeders only:
    (A) The continuous ampere rating of a fuse may not exceed three 
times the ampacity of the conductors. The long-time trip element 
setting of a breaker or the minimum trip setting of an electronically 
actuated fuse may not exceed six times the ampacity of the conductor. 
For fire pumps, conductors may be protected for short circuit only; and
    (B) Conductors tapped to a feeder may be protected by the feeder 
overcurrent device where that overcurrent device also protects the tap 
conductor.
    (g) Grounding. Paragraphs (g)(1) through (g)(9) of this section 
contain grounding requirements for systems, circuits, and equipment.
    (1) Systems to be grounded. Systems that supply premises wiring 
shall be grounded as follows:
    (i) All 3-wire dc systems shall have their neutral conductor 
grounded;
    (ii) Two-wire dc systems operating at over 50 volts through 300 
volts between conductors shall be grounded unless:
    (A) They supply only industrial equipment in limited areas and are 
equipped with a ground detector;
    (B) They are rectifier-derived from an ac system complying with 
paragraphs (g)(1)(iii), (g)(1)(iv), and (g)(1)(v) of this section; or
    (C) They are fire-alarm circuits having a maximum current of 0.030 
amperes;
    (iii) AC circuits of less than 50 volts shall be grounded if they 
are installed as overhead conductors outside of buildings or if they 
are supplied by transformers and the transformer primary supply system 
is ungrounded or exceeds 150 volts to ground;
    (iv) AC systems of 50 volts to 1000 volts shall be grounded under 
any of the following conditions, unless exempted by paragraph (g)(1)(v) 
of this section:
    (A) If the system can be so grounded that the maximum voltage to 
ground on the ungrounded conductors does not exceed 150 volts;
    (B) If the system is nominally rated three-phase, four-wire wye 
connected in which the neutral is used as a circuit conductor;
    (C) If the system is nominally rated three-phase, four-wire delta 
connected in which the midpoint of one phase is used as a circuit 
conductor; or
    (D) If a service conductor is uninsulated;
    (v) AC systems of 50 volts to 1000 volts are not required to be 
grounded under any of the following conditions:
    (A) If the system is used exclusively to supply industrial electric 
furnaces for melting, refining, tempering, and the like;
    (B) If the system is separately derived and is used exclusively for 
rectifiers supplying only adjustable speed industrial drives;
    (C) If the system is separately derived and is supplied by a 
transformer that has a primary voltage rating less than 1000 volts, 
provided all of the following conditions are met:
    (1) The system is used exclusively for control circuits;
    (2) The conditions of maintenance and supervision ensure that only 
qualified persons will service the installation;
    (3) Continuity of control power is required; and
    (4) Ground detectors are installed on the control system;
    (D) If the system is an isolated power system that supplies 
circuits in health care facilities; or
    (E) If the system is a high-impedance grounded neutral system in 
which a grounding impedance, usually a resistor, limits the ground-
fault current to a low value for 3-phase ac systems of 480 volts to 
1000 volts provided all of the following conditions are met:
    (1) The conditions of maintenance and supervision ensure that only 
qualified persons will service the installation;
    (2) Continuity of power is required;
    (3) Ground detectors are installed on the system; and
    (4) Line-to-neutral loads are not served.
    (2) Conductor to be grounded. The conductor to be grounded for ac 
premises wiring systems required to be grounded by paragraph (g)(1) of 
this section shall be as follows:
    (i) One conductor of a single-phase, two-wire system shall be 
grounded;
    (ii) The neutral conductor of a single-phase, three-wire system 
shall be grounded;
    (iii) The common conductor of a multiphase system having one wire 
common to all phases shall be grounded;
    (iv) One phase conductor of a multiphase system where one phase is 
grounded shall be grounded; and
    (v) The neutral conductor of a multiphase system in which one phase 
is used as a neutral conductor shall be grounded.
    (3) Portable and vehicle-mounted generators. (i) The frame of a 
portable generator need not be grounded and may serve as the grounding 
electrode for a system supplied by the generator under the following 
conditions:
    (A) The generator supplies only equipment mounted on the generator 
or cord- and plug-connected equipment through receptacles mounted on 
the generator, or both; and
    (B) The noncurrent-carrying metal parts of equipment and the 
equipment grounding conductor terminals of the receptacles are bonded 
to the generator frame.
    (ii) The frame of a vehicle need not be grounded and may serve as 
the grounding electrode for a system supplied by a generator located on 
the vehicle under the following conditions:
    (A) The frame of the generator is bonded to the vehicle frame;
    (B) The generator supplies only equipment located on the vehicle 
and cord- and plug-connected equipment through receptacles mounted on 
the vehicle;
    (C) The noncurrent-carrying metal parts of equipment and the 
equipment grounding conductor terminals of the receptacles are bonded 
to the generator frame; and
    (D) The system complies with all other provisions of paragraph (g) 
of this section.
    (iii) A system conductor that is required to be grounded by the 
provisions of paragraph (g)(2) of this section shall be bonded to the 
generator frame where the generator is a component of a separately 
derived system.
    (4) Grounding connections. (i) For a grounded system, a grounding 
electrode conductor shall be used to connect both the equipment 
grounding conductor and the grounded circuit conductor to the grounding 
electrode. Both the equipment grounding conductor and the grounding 
electrode conductor shall be connected to the grounded circuit 
conductor on the supply side of the service disconnecting means or on 
the supply side of the system disconnecting means or overcurrent 
devices if the system is separately derived.
    (ii) For an ungrounded service-supplied system, the equipment 
grounding conductor shall be connected to the grounding electrode 
conductor at the service equipment. For an ungrounded separately 
derived system, the equipment grounding conductor shall be connected to 
the grounding electrode conductor at, or ahead of, the system 
disconnecting means or overcurrent devices.
    (iii) On extensions of existing branch circuits that do not have an 
equipment grounding conductor, grounding-type receptacles may be 
grounded to a grounded cold water pipe near the equipment if the 
extension was installed before August 13, 2007. When any element of this 
branch circuit is replaced, the entire branch circuit shall use an equipment 
grounding conductor that complies with all other provisions of paragraph 
(g) of this section.
    (5) Grounding path. The path to ground from circuits, equipment, 
and enclosures shall be permanent, continuous, and effective.
    (6) Supports, enclosures, and equipment to be grounded. (i) Metal 
cable trays, metal raceways, and metal enclosures for conductors shall 
be grounded, except that:
    (A) Metal enclosures such as sleeves that are used to protect cable 
assemblies from physical damage need not be grounded; and
    (B) Metal enclosures for conductors added to existing installations 
of open wire, knob-and-tube wiring, and nonmetallic-sheathed cable need 
not be grounded if all of the following conditions are met:
    (1) Runs are less than 7.62 meters (25.0 ft);
    (2) Enclosures are free from probable contact with ground, grounded 
metal, metal laths, or other conductive materials; and
    (3) Enclosures are guarded against employee contact.
    (ii) Metal enclosures for service equipment shall be grounded.
    (iii) Frames of electric ranges, wall-mounted ovens, counter-
mounted cooking units, clothes dryers, and metal outlet or junction 
boxes that are part of the circuit for these appliances shall be 
grounded.
    (iv) Exposed noncurrent-carrying metal parts of fixed equipment 
that may become energized shall be grounded under any of the following 
conditions:
    (A) If within 2.44 m (8 ft) vertically or 1.52 m (5 ft) 
horizontally of ground or grounded metal objects and subject to 
employee contact;
    (B) If located in a wet or damp location and not isolated;
    (C) If in electrical contact with metal;
    (D) If in a hazardous (classified) location;
    (E) If supplied by a metal-clad, metal-sheathed, or grounded metal 
raceway wiring method; or
    (F) If equipment operates with any terminal at over 150 volts to 
ground.
    (v) Notwithstanding the provisions of paragraph (g)(6)(iv) of this 
section, exposed noncurrent-carrying metal parts of the following types 
of fixed equipment need not be grounded:
    (A) Enclosures for switches or circuit breakers used for other than 
service equipment and accessible to qualified persons only;
    (B) Electrically heated appliances that are permanently and 
effectively insulated from ground;
    (C) Distribution apparatus, such as transformer and capacitor 
cases, mounted on wooden poles, at a height exceeding 2.44 m (8.0 ft) 
above ground or grade level; and
    (D) Listed equipment protected by a system of double insulation, or 
its equivalent, and distinctively marked as such.
    (vi) Exposed noncurrent-carrying metal parts of cord- and plug-
connected equipment that may become energized shall be grounded under 
any of the following conditions:
    (A) If in hazardous (classified) locations (see Sec.  1910.307);
    (B) If operated at over 150 volts to ground, except for guarded 
motors and metal frames of electrically heated appliances if the 
appliance frames are permanently and effectively insulated from ground;
    (C) If the equipment is of the following types:
    (1) Refrigerators, freezers, and air conditioners;
    (2) Clothes-washing, clothes-drying, and dishwashing machines, sump 
pumps, and electric aquarium equipment;
    (3) Hand-held motor-operated tools, stationary and fixed motor-
operated tools, and light industrial motor-operated tools;
    (4) Motor-operated appliances of the following types: hedge 
clippers, lawn mowers, snow blowers, and wet scrubbers;
    (5) Cord- and plug-connected appliances used in damp or wet 
locations, or by employees standing on the ground or on metal floors or 
working inside of metal tanks or boilers;
    (6) Portable and mobile X-ray and associated equipment;
    (7) Tools likely to be used in wet and conductive locations; and
    (8) Portable hand lamps.
    (vii) Notwithstanding the provisions of paragraph (g)(6)(vi) of 
this section, the following equipment need not be grounded:
    (A) Tools likely to be used in wet and conductive locations if 
supplied through an isolating transformer with an ungrounded secondary 
of not over 50 volts; and
    (B) Listed or labeled portable tools and appliances if protected by 
an approved system of double insulation, or its equivalent, and 
distinctively marked.
    (7) Nonelectrical equipment. The metal parts of the following 
nonelectrical equipment shall be grounded: frames and tracks of 
electrically operated cranes and hoists; frames of nonelectrically 
driven elevator cars to which electric conductors are attached; hand-
operated metal shifting ropes or cables of electric elevators; and 
metal partitions, grill work, and similar metal enclosures around 
equipment of over 750 volts between conductors.
    (8) Methods of grounding fixed equipment. (i) Noncurrent-carrying 
metal parts of fixed equipment, if required to be grounded by this 
subpart, shall be grounded by an equipment grounding conductor that is 
contained within the same raceway, cable, or cord, or runs with or 
encloses the circuit conductors. For dc circuits only, the equipment 
grounding conductor may be run separately from the circuit conductors.
    (ii) Electric equipment is considered to be effectively grounded if 
it is secured to, and in electrical contact with, a metal rack or 
structure that is provided for its support and the metal rack or 
structure is grounded by the method specified for the noncurrent-
carrying metal parts of fixed equipment in paragraph (g)(8)(i) of this 
section. Metal car frames supported by metal hoisting cables attached 
to or running over metal sheaves or drums of grounded elevator machines 
are also considered to be effectively grounded.
    (iii) For installations made before April 16, 1981, electric 
equipment is also considered to be effectively grounded if it is 
secured to, and in metallic contact with, the grounded structural metal 
frame of a building. When any element of this branch circuit is 
replaced, the entire branch circuit shall use an equipment grounding 
conductor that complies with all other provisions of paragraph (g) of 
this section.
    (9) Grounding of systems and circuits of 1000 volts and over (high 
voltage). If high voltage systems are grounded, they shall comply with 
all applicable provisions of paragraphs (g)(1) through (g)(8) of this 
section as supplemented and modified by the following requirements:
    (i) Systems supplying portable or mobile high voltage equipment, 
other than substations installed on a temporary basis, shall comply 
with the following:
    (A) The system shall have its neutral grounded through an 
impedance. If a delta-connected high voltage system is used to supply 
the equipment, a system neutral shall be derived.
    (B) Exposed noncurrent-carrying metal parts of portable and mobile 
equipment shall be connected by an equipment grounding conductor to the 
point at which the system neutral impedance is grounded.
    (C) Ground-fault detection and relaying shall be provided to
automatically deenergize any high voltage system component that has 
developed a ground fault. The continuity of the equipment grounding 
conductor shall be continuously monitored so as to deenergize 
automatically the high voltage feeder to the portable equipment upon 
loss of continuity of the equipment grounding conductor.
    (D) The grounding electrode to which the portable equipment system 
neutral impedance is connected shall be isolated from and separated in 
the ground by at least 6.1 m (20.0 ft) from any other system or 
equipment grounding electrode, and there shall be no direct connection 
between the grounding electrodes, such as buried pipe, fence, and so 
forth.
    (ii) All noncurrent-carrying metal parts of portable equipment and 
fixed equipment, including their associated fences, housings, 
enclosures, and supporting structures, shall be grounded. However, 
equipment that is guarded by location and isolated from ground need not 
be grounded. Additionally, pole-mounted distribution apparatus at a 
height exceeding 2.44 m (8.0 ft) above ground or grade level need not 
be grounded.

Sec.  1910.305  Wiring methods, components, and equipment for general 
use.

    (a) Wiring methods. The provisions of this section do not apply to 
conductors that are an integral part of factory-assembled equipment.
    (1) General requirements. (i) Metal raceways, cable trays, cable 
armor, cable sheath, enclosures, frames, fittings, and other metal 
noncurrent-carrying parts that are to serve as grounding conductors, 
with or without the use of supplementary equipment grounding 
conductors, shall be effectively bonded where necessary to ensure 
electrical continuity and the capacity to conduct safely any fault 
current likely to be imposed on them. Any nonconductive paint, enamel, 
or similar coating shall be removed at threads, contact points, and 
contact surfaces or be connected by means of fittings designed so as to 
make such removal unnecessary.
    (ii) Where necessary for the reduction of electrical noise 
(electromagnetic interference) of the grounding circuit, an equipment 
enclosure supplied by a branch circuit may be isolated from a raceway 
containing circuits supplying only that equipment by one or more listed 
nonmetallic raceway fittings located at the point of attachment of the 
raceway to the equipment enclosure. The metal raceway shall be 
supplemented by an internal insulated equipment grounding conductor 
installed to ground the equipment enclosure.
    (iii) No wiring systems of any type may be installed in ducts used 
to transport dust, loose stock, or flammable vapors. No wiring system 
of any type may be installed in any duct used for vapor removal or for 
ventilation of commercial-type cooking equipment, or in any shaft 
containing only such ducts.
    (2) Temporary wiring. Except as specifically modified in this 
paragraph, all other requirements of this subpart for permanent wiring 
shall also apply to temporary wiring installations.
    (i) Temporary electrical power and lighting installations of 600 
volts, nominal, or less may be used only as follows:
    (A) During and for remodeling, maintenance, or repair of buildings, 
structures, or equipment, and similar activities;
    (B) For a period not to exceed 90 days for Christmas decorative 
lighting, carnivals, and similar purposes; or
    (C) For experimental or development work, and during emergencies.
    (ii) Temporary wiring shall be removed immediately upon completion 
of the project or purpose for which the wiring was installed.
    (iii) Temporary electrical installations of more than 600 volts may 
be used only during periods of tests, experiments, emergencies, or 
construction-like activities.
    (iv) The following requirements apply to feeders:
    (A) Feeders shall originate in an approved distribution center.
    (B) Conductors shall be run as multiconductor cord or cable 
assemblies. However, if installed as permitted in paragraph 
(a)(2)(i)(C) of this section, and if accessible only to qualified 
persons, feeders may be run as single insulated conductors.
    (v) The following requirements apply to branch circuits:
    (A) Branch circuits shall originate in an approved power outlet or 
panelboard.
    (B) Conductors shall be multiconductor cord or cable assemblies or 
open conductors. If run as open conductors, they shall be fastened at 
ceiling height every 3.05 m (10.0 ft).
    (C) No branch-circuit conductor may be laid on the floor.
    (D) Each branch circuit that supplies receptacles or fixed 
equipment shall contain a separate equipment grounding conductor if run 
as open conductors.
    (vi) Receptacles shall be of the grounding type. Unless installed 
in a continuous grounded metallic raceway or metallic covered cable, 
each branch circuit shall contain a separate equipment grounding 
conductor and all receptacles shall be electrically connected to the 
grounding conductor.
    (vii) No bare conductors nor earth returns may be used for the 
wiring of any temporary circuit.
    (viii) Suitable disconnecting switches or plug connectors shall be 
installed to permit the disconnection of all ungrounded conductors of 
each temporary circuit. Multiwire branch circuits shall be provided 
with a means to disconnect simultaneously all ungrounded conductors at 
the power outlet or panelboard where the branch circuit originated.

    Note to paragraph (a)(2)(viii) of this section. Circuit breakers 
with their handles connected by approved handle ties are considered 
a single disconnecting means for the purpose of this requirement.

    (ix) All lamps for general illumination shall be protected from 
accidental contact or breakage by a suitable fixture or lampholder with 
a guard. Brass shell, paper-lined sockets, or other metal-cased sockets 
may not be used unless the shell is grounded.
    (x) Flexible cords and cables shall be protected from accidental 
damage, as might be caused, for example, by sharp corners, projections, 
and doorways or other pinch points.
    (xi) Cable assemblies and flexible cords and cables shall be 
supported in place at intervals that ensure that they will be protected 
from physical damage. Support shall be in the form of staples, cables 
ties, straps, or similar type fittings installed so as not to cause 
damage.
    (3) Cable trays. (i) Only the following wiring methods may be 
installed in cable tray systems: armored cable; electrical metallic 
tubing; electrical nonmetallic tubing; fire alarm cables; flexible 
metal conduit; flexible metallic tubing; instrumentation tray cable; 
intermediate metal conduit; liquidtight flexible metal conduit; 
liquidtight flexible nonmetallic conduit; metal-clad cable; mineral-
insulated, metal-sheathed cable; multiconductor service-entrance cable; 
multiconductor underground feeder and branch-circuit cable; 
multipurpose and communications cables; nonmetallic-sheathed cable; 
power and control tray cable; power-limited tray cable; optical fiber 
cables; and other factory-assembled, multiconductor control, signal, or 
power cables that are specifically approved for installation in cable 
trays, rigid metal conduit, and rigid nonmetallic conduit.
    (ii) In industrial establishments where conditions of maintenance 
and supervision assure that only qualified persons will service the 
installed cable tray system, the following cables may also be installed 
in ladder, ventilated-trough, or ventilated-channel cable trays:
    (A) Single conductor cable; the cable shall be No. 1/0 or larger 
and shall be of a type listed and marked on the surface for use in 
cable trays; where Nos. 1/0 through 4/0 single conductor cables are 
installed in ladder cable tray, the maximum allowable rung spacing for 
the ladder cable tray shall be 229 mm (9 in.); where exposed to direct 
rays of the sun, cables shall be identified as being sunlight 
resistant;
    (B) Welding cables installed in dedicated cable trays;
    (C) Single conductors used as equipment grounding conductors; these 
conductors, which may be insulated, covered, or bare, shall be No. 4 or 
larger; and
    (D) Multiconductor cable, Type MV; where exposed to direct rays of 
the sun, the cable shall be identified as being sunlight resistant.
    (iii) Metallic cable trays may be used as equipment grounding 
conductors only where continuous maintenance and supervision ensure 
that qualified persons will service the installed cable tray system.
    (iv) Cable trays in hazardous (classified) locations may contain 
only the cable types permitted in such locations. (See Sec.  1910.307.)
    (v) Cable tray systems may not be used in hoistways or where 
subjected to severe physical damage.
    (4) Open wiring on insulators. (i) Open wiring on insulators is 
only permitted on systems of 600 volts, nominal, or less for industrial 
or agricultural establishments, indoors or outdoors, in wet or dry 
locations, where subject to corrosive vapors, and for services.
    (ii) Conductors smaller than No. 8 shall be rigidly supported on 
noncombustible, nonabsorbent insulating materials and may not contact 
any other objects. Supports shall be installed as follows:
    (A) Within 152 mm (6 in.) from a tap or splice;
    (B) Within 305 mm (12 in.) of a dead-end connection to a lampholder 
or receptacle; and
    (C) At intervals not exceeding 1.37 m (4.5 ft), and at closer 
intervals sufficient to provide adequate support where likely to be 
disturbed.
    (iii) In dry locations, where not exposed to severe physical 
damage, conductors may be separately enclosed in flexible nonmetallic 
tubing. The tubing shall be in continuous lengths not exceeding 4.57 m 
(15.0 ft) and secured to the surface by straps at intervals not 
exceeding 1.37 m (4.5 ft).
    (iv) Open conductors shall be separated from contact with walls, 
floors, wood cross members, or partitions through which they pass by 
tubes or bushings of noncombustible, nonabsorbent insulating material. 
If the bushing is shorter than the hole, a waterproof sleeve of 
nonconductive material shall be inserted in the hole and an insulating 
bushing slipped into the sleeve at each end in such a manner as to keep 
the conductors absolutely out of contact with the sleeve. Each 
conductor shall be carried through a separate tube or sleeve.
    (v) Where open conductors cross ceiling joints and wall studs and 
are exposed to physical damage (for example, located within 2.13 m (7.0 
ft) of the floor), they shall be protected.
    (b) Cabinets, boxes, and fittings--(1) Conductors entering boxes, 
cabinets, or fittings. (i) Conductors entering cutout boxes, cabinets, 
or fittings shall be protected from abrasion, and openings through 
which conductors enter shall be effectively closed.
    (ii) Unused openings in cabinets, boxes, and fittings shall be 
effectively closed.
    (iii) Where cable is used, each cable shall be secured to the 
cabinet, cutout box, or meter socket enclosure. However, where cable 
with an entirely nonmetallic sheath enters the top of a surface-mounted 
enclosure through one or more nonflexible raceways not less than 457 mm 
(18 in.) or more than 3.05 m (10.0 ft) in length, the cable need not be 
secured to the cabinet, box, or enclosure provided all of the following 
conditions are met:
    (A) Each cable is fastened within 305 mm (12 in.) of the outer end 
of the raceway, measured along the sheath;
    (B) The raceway extends directly above the enclosure and does not 
penetrate a structural ceiling;
    (C) A fitting is provided on each end of the raceway to protect the 
cable from abrasion, and the fittings remain accessible after 
installation;
    (D) The raceway is sealed or plugged at the outer end using 
approved means so as to prevent access to the enclosure through the 
raceway;
    (E) The cable sheath is continuous through the raceway and extends 
into the enclosure not less than 6.35 mm (0.25 in.) beyond the fitting;
    (F) The raceway is fastened at its outer end and at other points as 
necessary; and
    (G) Where installed as conduit or tubing, the allowable cable fill 
does not exceed that permitted for complete conduit or tubing systems.
    (2) Covers and canopies. (i) All pull boxes, junction boxes, and 
fittings shall be provided with covers identified for the purpose. If 
metal covers are used, they shall be grounded. In completed 
installations, each outlet box shall have a cover, faceplate, or 
fixture canopy. Covers of outlet boxes having holes through which 
flexible cord pendants pass shall be provided with bushings designed 
for the purpose or shall have smooth, well-rounded surfaces on which 
the cords may bear.
    (ii) Where a fixture canopy or pan is used, any combustible wall or 
ceiling finish exposed between the edge of the canopy or pan and the 
outlet box shall be covered with noncombustible material.
    (3) Pull and junction boxes for systems over 600 volts, nominal. In 
addition to other requirements in this section, the following 
requirements apply to pull and junction boxes for systems over 600 
volts, nominal:
    (i) Boxes shall provide a complete enclosure for the contained 
conductors or cables.
    (ii) Boxes shall be closed by suitable covers securely fastened in 
place.

    Note to paragraph (b)(3)(ii) of this section: Underground box 
covers that weigh over 45.4 kg (100 lbs) meet this requirement.

    (iii) Covers for boxes shall be permanently marked "HIGH 
VOLTAGE." The marking shall be on the outside of the box cover and 
shall be readily visible and legible.
    (c) Switches--(1) Single-throw knife switches. Single-throw knife 
switches shall be so placed that gravity will not tend to close them. 
Single-throw knife switches approved for use in the inverted position 
shall be provided with a locking device that will ensure that the 
blades remain in the open position when so set.
    (2) Double-throw knife switches. Double-throw knife switches may be 
mounted so that the throw will be either vertical or horizontal. 
However, if the throw is vertical, a locking device shall be provided 
to ensure that the blades remain in the open position when so set.
    (3) Connection of switches. (i) Single-throw knife switches and 
switches with butt contacts shall be connected so that the blades are 
deenergized when the switch is in the open position.
    (ii) Single-throw knife switches, molded-case switches, switches 
with butt contacts, and circuit breakers used as switches shall be 
connected so that the terminals supplying the load are deenergized when 
the switch is in the open position. However, blades and terminals 
supplying the load of a switch may be energized when the switch is in 
the open position where the switch is connected to circuits or equipment 
inherently capable of providing a backfeed source of power. For such 
installations, a permanent sign shall be installed on the switch enclosure 
or immediately adjacent to open switches that read, "WARNING--LOAD SIDE 
TERMINALS MAY BE ENERGIZED BY BACKFEED."
    (4) Faceplates for flush-mounted snap switches. Snap switches 
mounted in boxes shall have faceplates installed so as to completely 
cover the opening and seat against the finished surface.
    (5) Grounding. Snap switches, including dimmer switches, shall be 
effectively grounded and shall provide a means to ground metal 
faceplates, whether or not a metal faceplate is installed. However, if 
no grounding means exists within the snap-switch enclosure, or where 
the wiring method does not include or provide an equipment ground, a 
snap switch without a grounding connection is permitted for replacement 
purposes only. Such snap switches shall be provided with a faceplate of 
nonconducting, noncombustible material if they are located within reach 
of conducting floors or other conducting surfaces.
    (d) Switchboards and panelboards--(1) Switchboards with exposed 
live parts. Switchboards that have any exposed live parts shall be 
located in permanently dry locations and shall be accessible only to 
qualified persons.
    (2) Panelboard enclosures. Panelboards shall be mounted in 
cabinets, cutout boxes, or enclosures designed for the purpose and 
shall be dead front. However, panelboards other than the dead front 
externally-operable type are permitted where accessible only to 
qualified persons.
    (3) Knife switches mounted in switchboards or panelboards. Exposed 
blades of knife switches mounted in switchboards or panelboards shall 
be dead when open.
    (e) Enclosures for damp or wet locations--(1) Cabinets, cutout 
boxes, fittings, boxes, and panelboard enclosures. Cabinets, cutout 
boxes, fittings, boxes, and panelboard enclosures in damp or wet 
locations shall be installed so as to prevent moisture or water from 
entering and accumulating within the enclosures and shall be mounted so 
there is at least 6.35-mm (0.25-in.) airspace between the enclosure and 
the wall or other supporting surface. However, nonmetallic enclosures 
may be installed without the airspace on a concrete, masonry, tile, or 
similar surface. The enclosures shall be weatherproof in wet locations.
    (2) Switches, circuit breakers, and switchboards. Switches, circuit 
breakers, and switchboards installed in wet locations shall be enclosed 
in weatherproof enclosures.
    (f) Conductors for general wiring--(1) Insulation. All conductors 
used for general wiring shall be insulated unless otherwise permitted 
in this subpart.
    (2) Type. The conductor insulation shall be of a type that is 
approved for the voltage, operating temperature, and location of use.
    (3) Distinguishable. Insulated conductors shall be distinguishable 
by appropriate color or other suitable means as being grounded 
conductors, ungrounded conductors, or equipment grounding conductors.
    (g) Flexible cords and cables--(1)Use of flexible cords and cables. 
(i) Flexible cords and cables shall be approved for conditions of use 
and location.
    (ii) Flexible cords and cables may be used only for:
    (A) Pendants;
    (B) Wiring of fixtures;
    (C) Connection of portable lamps or appliances;
    (D) Portable and mobile signs;
    (E) Elevator cables;
    (F) Wiring of cranes and hoists;
    (G) Connection of stationary equipment to facilitate their frequent 
interchange;
    (H) Prevention of the transmission of noise or vibration;
    (I) Appliances where the fastening means and mechanical connections 
are designed to permit removal for maintenance and repair;
    (J) Data processing cables approved as a part of the data 
processing system;
    (K) Connection of moving parts; and
    (L) Temporary wiring as permitted in paragraph (a)(2) of this 
section.
    (iii) If used as permitted in paragraphs (g)(1)(ii)(C), 
(g)(1)(ii)(G), or (g)(1)(ii)(I) of this section, the flexible cord 
shall be equipped with an attachment plug and shall be energized from 
an approved receptacle outlet.
    (iv) Unless specifically permitted otherwise in paragraph 
(g)(1)(ii) of this section, flexible cords and cables may not be used:
    (A) As a substitute for the fixed wiring of a structure;
    (B) Where run through holes in walls, ceilings, or floors;
    (C) Where run through doorways, windows, or similar openings;
    (D) Where attached to building surfaces;
    (E) Where concealed behind building walls, ceilings, or floors; or
    (F) Where installed in raceways, except as otherwise permitted in 
this subpart.
    (v) Flexible cords used in show windows and showcases shall be Type 
S, SE, SEO, SEOO, SJ, SJE, SJEO, SJEOO, SJO, SJOO, SJT, SJTO, SJTOO, 
SO, SOO, ST, STO, or STOO, except for the wiring of chain-supported 
lighting fixtures and supply cords for portable lamps and other 
merchandise being displayed or exhibited.
    (2) Identification, splices, and terminations. (i) A conductor of a 
flexible cord or cable that is used as a grounded conductor or an 
equipment grounding conductor shall be distinguishable from other 
conductors. Types S, SC, SCE, SCT, SE, SEO, SEOO, SJ, SJE, SJEO, SJEOO, 
SJO, SJT, SJTO, SJTOO, SO, SOO, ST, STO, and STOO flexible cords and 
Types G, G-GC, PPE, and W flexible cables shall be durably marked on 
the surface at intervals not exceeding 610 mm (24 in.) with the type 
designation, size, and number of conductors.
    (ii) Flexible cords may be used only in continuous lengths without 
splice or tap. Hard-service cord and junior hard-service cord No. 14 
and larger may be repaired if spliced so that the splice retains the 
insulation, outer sheath properties, and usage characteristics of the 
cord being spliced.
    (iii) Flexible cords and cables shall be connected to devices and 
fittings so that strain relief is provided that will prevent pull from 
being directly transmitted to joints or terminal screws.
    (h) Portable cables over 600 volts, nominal. This paragraph applies 
to portable cables used at more than 600 volts, nominal.
    (1) Conductor construction. Multiconductor portable cable for use 
in supplying power to portable or mobile equipment at over 600 volts, 
nominal, shall consist of No. 8 or larger conductors employing flexible 
stranding. However, the minimum size of the insulated ground-check 
conductor of Type G-GC cables shall be No. 10.
    (2) Shielding. Cables operated at over 2,000 volts shall be 
shielded for the purpose of confining the voltage stresses to the 
insulation.
    (3) Equipment grounding conductors. Grounding conductors shall be 
provided.
    (4) Grounding shields. All shields shall be grounded.
    (5) Minimum bending radii. The minimum bending radii for portable 
cables during installation and handling in service shall be adequate to 
prevent damage to the cable.
    (6) Fittings. Connectors used to connect lengths of cable in a run 
shall be of a type that lock firmly together. Provisions shall be made to 
prevent opening or closing these connectors while energized. Strain 
relief shall be provided at connections and terminations.
    (7) Splices. Portable cables may not be operated with splices 
unless the splices are of the permanent molded, vulcanized, or other 
approved type.
    (8) Terminations. Termination enclosures shall be suitably marked 
with a high voltage hazard warning, and terminations shall be 
accessible only to authorized and qualified employees.
    (i) Fixture wires--(1) General. Fixture wires shall be approved for 
the voltage, temperature, and location of use. A fixture wire which is 
used as a grounded conductor shall be identified.
    (2) Uses permitted. Fixture wires may be used only:
    (i) For installation in lighting fixtures and in similar equipment 
where enclosed or protected and not subject to bending or twisting in 
use; or
    (ii) For connecting lighting fixtures to the branch-circuit 
conductors supplying the fixtures.
    (3) Uses not permitted. Fixture wires may not be used as branch-
circuit conductors except as permitted for Class 1 power limited 
circuits and for fire alarm circuits.
    (j) Equipment for general use--(1) Lighting fixtures, lampholders, 
lamps, and receptacles. (i) Fixtures, lampholders, lamps, rosettes, and 
receptacles may have no live parts normally exposed to employee 
contact. However, rosettes and cleat-type lampholders and receptacles 
located at least 2.44 m (8.0 ft) above the floor may have exposed 
terminals.
    (ii) Handlamps of the portable type supplied through flexible cords 
shall be equipped with a handle of molded composition or other material 
identified for the purpose, and a substantial guard shall be attached 
to the lampholder or the handle. Metal shell, paper-lined lampholders 
may not be used.
    (iii) Lampholders of the screw-shell type shall be installed for 
use as lampholders only. Where supplied by a circuit having a grounded 
conductor, the grounded conductor shall be connected to the screw 
shell. Lampholders installed in wet or damp locations shall be of the 
weatherproof type.
    (iv) Fixtures installed in wet or damp locations shall be 
identified for the purpose and shall be so constructed or installed 
that water cannot enter or accumulate in wireways, lampholders, or 
other electrical parts.
    (2) Receptacles, cord connectors, and attachment plugs (caps). (i) 
All 15- and 20-ampere attachment plugs and connectors shall be 
constructed so that there are no exposed current-carrying parts except 
the prongs, blades, or pins. The cover for wire terminations shall be a 
part that is essential for the operation of an attachment plug or 
connector (dead-front construction). Attachment plugs shall be 
installed so that their prongs, blades, or pins are not energized 
unless inserted into an energized receptacle. No receptacles may be 
installed so as to require an energized attachment plug as its source 
of supply.
    (ii) Receptacles, cord connectors, and attachment plugs shall be 
constructed so that no receptacle or cord connector will accept an 
attachment plug with a different voltage or current rating than that 
for which the device is intended. However, a 20-ampere T-slot 
receptacle or cord connector may accept a 15-ampere attachment plug of 
the same voltage rating.
    (iii) Nongrounding-type receptacles and connectors may not be used 
for grounding-type attachment plugs.
    (iv) A receptacle installed in a wet or damp location shall be 
suitable for the location.
    (v) A receptacle installed outdoors in a location protected from 
the weather or in other damp locations shall have an enclosure for the 
receptacle that is weatherproof when the receptacle is covered 
(attachment plug cap not inserted and receptacle covers closed).

    Note to paragraph (j)(2)(v) of this section. A receptacle is 
considered to be in a location protected from the weather when it is 
located under roofed open porches, canopies, marquees, or the like 
and where it will not be subjected to a beating rain or water 
runoff.

    (vi) A receptacle installed in a wet location where the product 
intended to be plugged into it is not attended while in use (for 
example, sprinkler system controllers, landscape lighting, and holiday 
lights) shall have an enclosure that is weatherproof with the 
attachment plug cap inserted or removed.
    (vii) A receptacle installed in a wet location where the product 
intended to be plugged into it will be attended while in use (for 
example, portable tools) shall have an enclosure that is weatherproof 
when the attachment plug cap is removed.
    (3) Appliances. (i) Appliances may have no live parts normally 
exposed to contact other than parts functioning as open-resistance 
heating elements, such as the heating elements of a toaster, which are 
necessarily exposed.
    (ii) Each appliance shall have a means to disconnect it from all 
ungrounded conductors. If an appliance is supplied by more than one 
source, the disconnecting means shall be grouped and identified.
    (iii) Each electric appliance shall be provided with a nameplate 
giving the identifying name and the rating in volts and amperes, or in 
volts and watts. If the appliance is to be used on a specific frequency 
or frequencies, it shall be so marked. Where motor overload protection 
external to the appliance is required, the appliance shall be so 
marked.
    (iv) Marking shall be located so as to be visible or easily 
accessible after installation.
    (4) Motors. This paragraph applies to motors, motor circuits, and 
controllers.
    (i) If specified in paragraph (j)(4) of this section that one piece 
of equipment shall be "within sight of" another piece of equipment, 
the piece of equipment shall be visible and not more than 15.24 m (50.0 
ft) from the other.
    (ii) An individual disconnecting means shall be provided for each 
controller. A disconnecting means shall be located within sight of the 
controller location. However, a single disconnecting means may be 
located adjacent to a group of coordinated controllers mounted adjacent 
to each other on a multi-motor continuous process machine. The 
controller disconnecting means for motor branch circuits over 600 
volts, nominal, may be out of sight of the controller, if the 
controller is marked with a warning label giving the location and 
identification of the disconnecting means that is to be locked in the 
open position.
    (iii) The disconnecting means shall disconnect the motor and the 
controller from all ungrounded supply conductors and shall be so 
designed that no pole can be operated independently.
    (iv) The disconnecting means shall plainly indicate whether it is 
in the open (off) or closed (on) position.
    (v) The disconnecting means shall be readily accessible. If more 
than one disconnect is provided for the same equipment, only one need 
be readily accessible.
    (vi) An individual disconnecting means shall be provided for each 
motor, but a single disconnecting means may be used for a group of 
motors under any one of the following conditions:
    (A) If a number of motors drive several parts of a single machine 
or piece of apparatus, such as a metal or woodworking machine, crane, 
or hoist;
    (B) If a group of motors is under the protection of one set of 
branch-circuit protective devices; or
    (C) If a group of motors is in a single room within sight of the 
location of the disconnecting means.
    (vii) Motors, motor-control apparatus, and motor branch-circuit 
conductors shall be protected against overheating due to motor 
overloads or failure to start, and against short-circuits or ground 
faults. These provisions do not require overload protection that will 
stop a motor where a shutdown is likely to introduce additional or 
increased hazards, as in the case of fire pumps, or where continued 
operation of a motor is necessary for a safe shutdown of equipment or 
process and motor overload sensing devices are connected to a 
supervised alarm.
    (viii) Where live parts of motors or controllers operating at over 
150 volts to ground are guarded against accidental contact only by 
location, and where adjustment or other attendance may be necessary 
during the operation of the apparatus, suitable insulating mats or 
platforms shall be provided so that the attendant cannot readily touch 
live parts unless standing on the mats or platforms.
    (5) Transformers. (i) Paragraph (j)(5) of this section covers the 
installation of all transformers except the following:
    (A) Current transformers;
    (B) Dry-type transformers installed as a component part of other 
apparatus;
    (C) Transformers that are an integral part of an X-ray, high 
frequency, or electrostatic-coating apparatus;
    (D) Transformers used with Class 2 and Class 3 circuits, sign and 
outline lighting, electric discharge lighting, and power-limited fire-
alarm circuits; and
    (E) Liquid-filled or dry-type transformers used for research, 
development, or testing, where effective safeguard arrangements are 
provided.
    (ii) The operating voltage of exposed live parts of transformer 
installations shall be indicated by signs or visible markings on the 
equipment or structure.
    (iii) Dry-type, high fire point liquid-insulated, and askarel-
insulated transformers installed indoors and rated over 35kV shall be 
in a vault.
    (iv) Oil-insulated transformers installed indoors shall be 
installed in a vault.
    (v) Combustible material, combustible buildings and parts of 
buildings, fire escapes, and door and window openings shall be 
safeguarded from fires that may originate in oil-insulated transformers 
attached to or adjacent to a building or combustible material.
    (vi) Transformer vaults shall be constructed so as to contain fire 
and combustible liquids within the vault and to prevent unauthorized 
access. Locks and latches shall be so arranged that a vault door can be 
readily opened from the inside.
    (vii) Any pipe or duct system foreign to the electrical 
installation may not enter or pass through a transformer vault.

    Note to paragraph (j)(5)(vii) of this section. Piping or other 
facilities provided for vault fire protection, or for transformer 
cooling, are not considered foreign to the electrical installation.

    (viii) Material may not be stored in transformer vaults.
    (6) Capacitors. (i) All capacitors, except surge capacitors or 
capacitors included as a component part of other apparatus, shall be 
provided with an automatic means of draining the stored charge after 
the capacitor is disconnected from its source of supply.
    (ii) The following requirements apply to capacitors installed on 
circuits operating at more than 600 volts, nominal:
    (A) Group-operated switches shall be used for capacitor switching 
and shall be capable of the following:
    (1) Carrying continuously not less than 135 percent of the rated 
current of the capacitor installation;
    (2) Interrupting the maximum continuous load current of each 
capacitor, capacitor bank, or capacitor installation that will be 
switched as a unit;
    (3) Withstanding the maximum inrush current, including 
contributions from adjacent capacitor installations; and
    (4) Carrying currents due to faults on the capacitor side of the 
switch;
    (B) A means shall be installed to isolate from all sources of 
voltage each capacitor, capacitor bank, or capacitor installation that 
will be removed from service as a unit. The isolating means shall 
provide a visible gap in the electric circuit adequate for the 
operating voltage;
    (C) Isolating or disconnecting switches (with no interrupting 
rating) shall be interlocked with the load interrupting device or shall 
be provided with prominently displayed caution signs to prevent 
switching load current; and
    (D) For series capacitors, the proper switching shall be assured by 
use of at least one of the following:
    (1) Mechanically sequenced isolating and bypass switches;
    (2) Interlocks; or
    (3) Switching procedure prominently displayed at the switching 
location.
    (7) Storage Batteries. Provisions shall be made for sufficient 
diffusion and ventilation of gases from storage batteries to prevent 
the accumulation of explosive mixtures.

Sec.  1910.306  Specific purpose equipment and installations.

    (a) Electric signs and outline lighting--(1) Disconnecting means. 
(i) Each sign and outline lighting system, or feeder circuit or branch 
circuit supplying a sign or outline lighting system, shall be 
controlled by an externally operable switch or circuit breaker that 
will open all ungrounded conductors. However, a disconnecting means is 
not required for an exit directional sign located within a building or 
for cord-connected signs with an attachment plug.
    (ii) Signs and outline lighting systems located within fountains 
shall have the disconnect located at least 1.52 m (5.0 ft) from the 
inside walls of the fountain.
    (2) Location. (i) The disconnecting means shall be within sight of 
the sign or outline lighting system that it controls. Where the 
disconnecting means is out of the line of sight from any section that 
may be energized, the disconnecting means shall be capable of being 
locked in the open position.
    (ii) Signs or outline lighting systems operated by electronic or 
electromechanical controllers located external to the sign or outline 
lighting system may have a disconnecting means located within sight of 
the controller or in the same enclosure with the controller. The 
disconnecting means shall disconnect the sign or outline lighting 
system and the controller from all ungrounded supply conductors. It 
shall be designed so no pole can be operated independently and shall be 
capable of being locked in the open position.
    (iii) Doors or covers giving access to uninsulated parts of indoor 
signs or outline lighting exceeding 600 volts and accessible to other 
than qualified persons shall either be provided with interlock switches 
to disconnect the primary circuit or shall be so fastened that the use 
of other than ordinary tools will be necessary to open them.
    (b) Cranes and hoists. This paragraph applies to the installation 
of electric equipment and wiring used in connection with cranes, 
monorail hoists, hoists, and all runways.
    (1) Disconnecting means for runway conductors. A disconnecting 
means shall be provided between the runway contact conductors and the 
power supply. Such disconnecting means shall consist of a motor-circuit 
switch, circuit breaker, or molded case switch. The disconnecting means 
shall open all ungrounded conductors simultaneously and shall be:
    (i) Readily accessible and operable from the ground or floor level;
    (ii) Arranged to be locked in the open position; and
    (iii) Placed within view of the runway contact conductors.
    (2) Disconnecting means for cranes and monorail hoists. (i) Except 
as provided in paragraph (b)(2)(iv) of this section, a motor-circuit 
switch, molded case switch, or circuit breaker shall be provided in the 
leads from the runway contact conductors or other power supply on all 
cranes and monorail hoists.
    (ii) The disconnecting means shall be capable of being locked in 
the open position.
    (iii) Means shall be provided at the operating station to open the 
power circuit to all motors of the crane or monorail hoist where the 
disconnecting means is not readily accessible from the crane or 
monorail hoist operating station.
    (iv) The disconnecting means may be omitted where a monorail hoist 
or hand-propelled crane bridge installation meets all of the following 
conditions:
    (A) The unit is controlled from the ground or floor level;
    (B) The unit is within view of the power supply disconnecting 
means; and
    (C) No fixed work platform has been provided for servicing the 
unit.
    (3) Limit switch. A limit switch or other device shall be provided 
to prevent the load block from passing the safe upper limit of travel 
of any hoisting mechanism.
    (4) Clearance. The dimension of the working space in the direction 
of access to live parts that may require examination, adjustment, 
servicing, or maintenance while alive shall be a minimum of 762 mm (2.5 
ft). Where controls are enclosed in cabinets, the doors shall either 
open at least 90 degrees or be removable.
    (c) Elevators, dumbwaiters, escalators, moving walks, wheelchair 
lifts, and stairway chair lifts. The following requirements apply to 
elevators, dumbwaiters, escalators, moving walks, wheelchair lifts, and 
stairway chair lifts.
    (1) Disconnecting means. Elevators, dumbwaiters, escalators, moving 
walks, wheelchair lifts, and stairway chair lifts shall have a single 
means for disconnecting all ungrounded main power supply conductors for 
each unit.
    (2) Control panels. Control panels not located in the same space as 
the drive machine shall be located in cabinets with doors or panels 
capable of being locked closed.
    (3) Type. The disconnecting means shall be an enclosed externally 
operable fused motor circuit switch or circuit breaker capable of being 
locked in the open position. The disconnecting means shall be a listed 
device.
    (4) Operation. No provision may be made to open or close this 
disconnecting means from any other part of the premises. If sprinklers 
are installed in hoistways, machine rooms, or machinery spaces, the 
disconnecting means may automatically open the power supply to the 
affected elevators prior to the application of water. No provision may 
be made to close this disconnecting means automatically (that is, power 
may only be restored by manual means).
    (5) Location. The disconnecting means shall be located where it is 
readily accessible to qualified persons.
    (i) On elevators without generator field control, the disconnecting 
means shall be located within sight of the motor controller. Driving 
machines or motion and operation controllers not within sight of the 
disconnecting means shall be provided with a manually operated switch 
installed in the control circuit adjacent to the equipment in order to 
prevent starting. Where the driving machine is located in a remote 
machinery space, a single disconnecting means for disconnecting all 
ungrounded main power supply conductors shall be provided and be 
capable of being locked in the open position.
    (ii) On elevators with generator field control, the disconnecting 
means shall be located within sight of the motor controller for the 
driving motor of the motor-generator set. Driving machines, motor-
generator sets, or motion and operation controllers not within sight of 
the disconnecting means shall be provided with a manually operated 
switch installed in the control circuit to prevent starting. The 
manually operated switch shall be installed adjacent to this equipment. 
Where the driving machine or the motor-generator set is located in a 
remote machinery space, a single means for disconnecting all ungrounded 
main power supply conductors shall be provided and be capable of being 
locked in the open position.
    (iii) On escalators and moving walks, the disconnecting means shall 
be installed in the space where the controller is located.
    (iv) On wheelchair lifts and stairway chair lifts, the 
disconnecting means shall be located within sight of the motor 
controller.
    (6) Identification and signs. (i) Where there is more than one 
driving machine in a machine room, the disconnecting means shall be 
numbered to correspond to the identifying number of the driving machine 
that they control.
    (ii) The disconnecting means shall be provided with a sign to 
identify the location of the supply-side overcurrent protective device.
    (7) Single-car and multicar installations. On single-car and 
multicar installations, equipment receiving electrical power from more 
than one source shall be provided with a disconnecting means for each 
source of electrical power. The disconnecting means shall be within 
sight of the equipment served.
    (8) Warning sign for multiple disconnecting means. A warning sign 
shall be mounted on or next to the disconnecting means where multiple 
disconnecting means are used and parts of the controllers remain 
energized from a source other than the one disconnected. The sign shall 
be clearly legible and shall read "WARNING--PARTS OF THE CONTROLLER 
ARE NOT DEENERGIZED BY THIS SWITCH."
    (9) Interconnection between multicar controllers. A warning sign 
worded as required in paragraph (c)(8) of this section shall be mounted 
on or next to the disconnecting means where interconnections between 
controllers are necessary for the operation of the system on multicar 
installations that remain energized from a source other than the one 
disconnected.
    (10) Motor controllers. Motor controllers may be located outside 
the spaces otherwise required by paragraph (c) of this section, 
provided they are in enclosures with doors or removable panels capable 
of being locked closed and the disconnecting means is located adjacent 
to or is an integral part of the motor controller. Motor controller 
enclosures for escalators or moving walks may be located in the 
balustrade on the side located away from the moving steps or moving 
treadway. If the disconnecting means is an integral part of the motor 
controller, it shall be operable without opening the enclosure.
    (d) Electric welders--disconnecting means--(1) Arc welders. A 
disconnecting means shall be provided in the supply circuit for each 
arc welder that is not equipped with a disconnect mounted as an 
integral part of the welder. The disconnecting means shall be a switch 
or circuit breaker, and its rating may not be less than that necessary 
to accommodate overcurrent protection.
    (2) Resistance welders. A switch or circuit breaker shall be 
provided by which each resistance welder and its control equipment can 
be disconnected from the supply circuit. The ampere rating of this 
disconnecting means may not be less than the supply conductor ampacity. 
The supply circuit switch may be used as the welder disconnecting means 
where the circuit supplies only one welder.
    (e) Information technology equipment--(1) Disconnecting means. A 
means shall be provided to disconnect power to all electronic equipment 
in an information technology equipment room. There shall also be a 
similar means to disconnect the power to all dedicated heating, 
ventilating, and air-conditioning (HVAC) systems serving the room and 
to cause all required fire/smoke dampers to close.
    (2) Grouping. The control for these disconnecting means shall be 
grouped and identified and shall be readily accessible at the principal 
exit doors. A single means to control both the electronic equipment and 
HVAC system is permitted.
    (3) Exception. Integrated electrical systems covered by Sec.  
1910.308(g) need not have the disconnecting means required by paragraph 
(e)(1) of this section.
    (f) X-Ray equipment. This paragraph applies to X-ray equipment.
    (1) Disconnecting means. (i) A disconnecting means shall be 
provided in the supply circuit. The disconnecting means shall be 
operable from a location readily accessible from the X-ray control. For 
equipment connected to a 120-volt branch circuit of 30 amperes or less, 
a grounding-type attachment plug cap and receptacle of proper rating 
may serve as a disconnecting means.
    (ii) If more than one piece of equipment is operated from the same 
high-voltage circuit, each piece or each group of equipment as a unit 
shall be provided with a high-voltage switch or equivalent 
disconnecting means. The disconnecting means shall be constructed, 
enclosed, or located so as to avoid contact by employees with its live 
parts.
    (2) Control. The following requirements apply to industrial and 
commercial laboratory equipment.
    (i) Radiographic and fluoroscopic-type equipment shall be 
effectively enclosed or shall have interlocks that deenergize the 
equipment automatically to prevent ready access to live current-
carrying parts.
    (ii) Diffraction- and irradiation-type equipment shall have a pilot 
light, readable meter deflection, or equivalent means to indicate when 
the equipment is energized, unless the equipment or installation is 
effectively enclosed or is provided with interlocks to prevent access 
to live current-carrying parts during operation.
    (g) Induction and dielectric heating equipment. This paragraph 
applies to induction and dielectric heating equipment and accessories 
for industrial and scientific applications, but not for medical or 
dental applications or for appliances.
    (1) Guarding and grounding. (i) The converting apparatus (including 
the dc line) and high-frequency electric circuits (excluding the output 
circuits and remote-control circuits) shall be completely contained 
within enclosures of noncombustible material.
    (ii) All panel controls shall be of dead-front construction.
    (iii) Doors or detachable panels shall be employed for internal 
access. Where doors are used giving access to voltages from 500 to 1000 
volts ac or dc, either door locks shall be provided or interlocks shall 
be installed. Where doors are used giving access to voltages of over 
1000 volts ac or dc, either mechanical lockouts with a disconnecting 
means to prevent access until circuit parts within the cubicle are 
deenergized, or both door interlocking and mechanical door locks, shall 
be provided. Detachable panels not normally used for access to such 
parts shall be fastened in a manner that will make them difficult to 
remove (for example, by requiring the use of tools).
    (iv) Warning labels or signs that read "DANGER--HIGH VOLTAGE--KEEP 
OUT" shall be attached to the equipment and shall be plainly visible 
where persons might contact energized parts when doors are opened or 
closed or when panels are removed from compartments containing over 250 
volts ac or dc.
    (v) Induction and dielectric heating equipment shall be protected 
as follows:
    (A) Protective cages or adequate shielding shall be used to guard 
work applicators other than induction heating coils.
    (B) Induction heating coils shall be protected by insulation or 
refractory materials or both.
    (C) Interlock switches shall be used on all hinged access doors, 
sliding panels, or other such means of access to the applicator, unless 
the applicator is an induction heating coil at dc ground potential or 
operating at less than 150 volts ac.
    (D) Interlock switches shall be connected in such a manner as to 
remove all power from the applicator when any one of the access doors 
or panels is open.
    (vi) A readily accessible disconnecting means shall be provided by 
which each heating equipment can be isolated from its supply circuit. 
The ampere rating of this disconnecting means may not be less than the 
nameplate current rating of the equipment. The supply circuit 
disconnecting means is permitted as a heating equipment disconnecting 
means where the circuit supplies only one piece of equipment.
    (2) Remote control. (i) If remote controls are used for applying 
power, a selector switch shall be provided and interlocked to provide 
power from only one control point at a time.
    (ii) Switches operated by foot pressure shall be provided with a 
shield over the contact button to avoid accidental closing of the 
switch.
    (h) Electrolytic cells. This paragraph applies to the installation 
of the electrical components and accessory equipment of electrolytic 
cells, electrolytic cell lines, and process power supply for the 
production of aluminum, cadmium, chlorine, copper, fluorine, hydrogen 
peroxide, magnesium, sodium, sodium chlorate, and zinc. Cells used as a 
source of electric energy and for electroplating processes and cells 
used for production of hydrogen are not covered by this paragraph.
    (1) Application. Installations covered by paragraph (h) of this 
section shall comply with all applicable provisions of this subpart, 
except as follows:
    (i) Overcurrent protection of electrolytic cell dc process power 
circuits need not comply with the requirements of Sec.  1910.304(f);
    (ii) Equipment located or used within the cell line working zone or 
associated with the cell line dc power circuits need not comply with 
the provisions of Sec.  1910.304(g); and
    (iii) Electrolytic cells, cell line conductors, cell line 
attachments, and the wiring of auxiliary equipment and devices within 
the cell line working zone need not comply with the provisions of Sec.  
1910.303 or Sec.  1910.304(b) and (c).
    (2) Disconnecting means. If more than one dc cell line process 
power supply serves the same cell line, a disconnecting means shall be 
provided on the cell line circuit side of each power supply to 
disconnect it from the cell line circuit. Removable links or removable 
conductors may be used as the disconnecting means.
    (3) Portable electric equipment. (i) The frames and enclosures of 
portable electric equipment used within the cell line working zone may 
not be grounded, unless the cell line circuit voltage does not exceed 
200 volts DC or the frames are guarded.
    (ii) Ungrounded portable electric equipment shall be distinctively 
marked and shall employ plugs and receptacles of a configuration that 
prevents connection of this equipment to grounding receptacles and that 
prevents inadvertent interchange of ungrounded and grounded portable 
electric equipment.
    (4) Power supply circuits and receptacles for portable electric 
equipment. (i) Circuits supplying power to ungrounded receptacles for 
hand-held, cord- and plug-connected equipment shall meet the following 
requirements:
    (A) The circuits shall be electrically isolated from any 
distribution system supplying areas other than the cell line working 
zone and shall be ungrounded;
    (B) The circuits shall be supplied through isolating transformers 
with primaries operating at not more than 600 volts between conductors 
and protected with proper overcurrent protection;
    (C) The secondary voltage of the isolating transformers may not 
exceed 300 volts between conductors; and
    (D) All circuits supplied from the secondaries shall be ungrounded 
and shall have an approved overcurrent device of proper rating in each 
conductor.
    (ii) Receptacles and their mating plugs for ungrounded equipment 
may not have provision for a grounding conductor and shall be of a 
configuration that prevents their use for equipment required to be 
grounded.
    (iii) Receptacles on circuits supplied by an isolating transformer 
with an ungrounded secondary:
    (A) Shall have a distinctive configuration;
    (B) Shall be distinctively marked; and
    (C) May not be used in any other location in the facility.
    (5) Fixed and portable electric equipment. (i) The following need 
not be grounded:
    (A) AC systems supplying fixed and portable electric equipment 
within the cell line working zone; and
    (B) Exposed conductive surfaces, such as electric equipment 
housings, cabinets, boxes, motors, raceways and the like that are 
within the cell line working zone.
    (ii) Auxiliary electric equipment, such as motors, transducers, 
sensors, control devices, and alarms, mounted on an electrolytic cell 
or other energized surface shall be connected to the premises wiring 
systems by any of the following means:
    (A) Multiconductor hard usage or extra hard usage flexible cord;
    (B) Wire or cable in suitable nonmetallic raceways or cable trays; 
or
    (C) Wire or cable in suitable metal raceways or metal cable trays 
installed with insulating breaks such that they will not cause a 
potentially hazardous electrical condition.
    (iii) Fixed electric equipment may be bonded to the energized 
conductive surfaces of the cell line, its attachments, or auxiliaries. 
If fixed electric equipment is mounted on an energized conductive 
surface, it shall be bonded to that surface.
    (6) Auxiliary nonelectrical connections. Auxiliary nonelectrical 
connections such as air hoses, water hoses, and the like, to an 
electrolytic cell, its attachments, or auxiliary equipment may not have 
continuous conductive reinforcing wire, armor, braids, or the like. 
Hoses shall be of a nonconductive material.
    (7) Cranes and hoists. (i) The conductive surfaces of cranes and 
hoists that enter the cell line working zone need not be grounded. The 
portion of an overhead crane or hoist that contacts an energized 
electrolytic cell or energized attachments shall be insulated from 
ground.
    (ii) Remote crane or hoist controls that may introduce hazardous 
electrical conditions into the cell line working zone shall employ one 
or more of the following systems:
    (A) Isolated and ungrounded control circuit;
    (B) Nonconductive rope operator;
    (C) Pendant pushbutton with nonconductive supporting means and with 
nonconductive surfaces or ungrounded exposed conductive surfaces; or
    (D) Radio.
    (i) Electrically driven or controlled irrigation machines--(1) 
Lightning protection. If an irrigation machine has a stationary point, 
a grounding electrode system shall be connected to the machine at the 
stationary point for lightning protection.
    (2) Disconnecting means. (i) The main disconnecting means for a 
center pivot irrigation machine shall be located at the point of 
connection of electrical power to the machine or shall be visible and 
not more than 15.2 m (50 ft) from the machine.
    (ii) The disconnecting means shall be readily accessible and 
capable of being locked in the open position.
    (iii) A disconnecting means shall be provided for each motor and 
controller.
    (j) Swimming pools, fountains, and similar installations. This 
paragraph applies to electric wiring for and equipment in or adjacent 
to all swimming, wading, therapeutic, and decorative pools and 
fountains; hydro-massage bathtubs, whether permanently installed or 
storable; and metallic auxiliary equipment, such as pumps, filters, and 
similar equipment. Therapeutic pools in health care facilities are 
exempt from these provisions.
    (1) Receptacles. (i) A single receptacle of the locking and 
grounding type that provides power for a permanently installed swimming 
pool recirculating pump motor may be located not less than 1.52 m (5 
ft) from the inside walls of a pool. All other receptacles on the 
property shall be located at least 3.05 m (10 ft) from the inside walls 
of a pool.
    (ii) Receptacles that are located within 4.57 m (15 ft), or 6.08 m 
(20 ft) if the installation was built after August 13, 2007, of the 
inside walls of the pool shall be protected by ground-fault circuit 
interrupters.
    (iii) Where a pool is installed permanently at a dwelling unit, at 
least one 125-volt, 15- or 20-ampere receptacle on a general-purpose 
branch circuit shall be located a minimum of 3.05 m (10 ft) and not 
more than 6.08 m (20 ft) from the inside wall of the pool. This 
receptacle shall be located not more than 1.98 m (6.5 ft) above the 
floor, platform, or grade level serving the pool.

    Note to paragraph (j)(1) of this section: In determining these 
dimensions, the distance to be measured is the shortest path the 
supply cord of an appliance connected to the receptacle would follow 
without piercing a floor, wall, or ceiling of a building or other 
effective permanent barrier.

    (2) Lighting fixtures, lighting outlets, and ceiling suspended 
(paddle) fans. (i) In outdoor pool areas, lighting fixtures, lighting 
outlets, and ceiling-suspended (paddle) fans may not be installed over 
the pool or over the area extending 1.52 m (5 ft) horizontally from the 
inside walls of a pool unless no part of the lighting fixture of a 
ceiling-suspended (paddle) fan is less than 3.66 m (12 ft) above the 
maximum water level. However, a lighting fixture or lighting outlet 
that was installed before April 16, 1981, may be located less than 1.52 
m (5 ft) measured horizontally from the inside walls of a pool if it is 
at least 1.52 m (5 ft) above the surface of the maximum water level and 
is rigidly attached to the existing structure. It shall also be 
protected by a ground-fault circuit interrupter installed in the branch 
circuit supplying the fixture.
    (ii) Lighting fixtures and lighting outlets installed in the area 
extending between 1.52 m (5 ft) and 3.05 m (10 ft) horizontally from 
the inside walls of a pool shall be protected by a ground-fault circuit 
interrupter unless installed 1.52 m (5 ft) above the maximum water 
level and rigidly attached to the structure adjacent to or enclosing 
the pool.
    (3) Cord- and plug-connected equipment. Flexible cords used with 
the following equipment may not exceed 0.9 m (3 ft) in length and shall 
have a copper equipment grounding conductor with a grounding-type attachment 
plug:
    (i) Cord- and plug-connected lighting fixtures installed within 
4.88 m (16 ft) of the water surface of permanently installed pools; and
    (ii) Other cord- and plug-connected, fixed or stationary equipment 
used with permanently installed pools.
    (4) Underwater equipment. (i) A ground-fault circuit interrupter 
shall be installed in the branch circuit supplying underwater fixtures 
operating at more than 15 volts. Equipment installed underwater shall 
be identified for the purpose.
    (ii) No underwater lighting fixtures may be installed for operation 
at over 150 volts between conductors.
    (iii) A lighting fixture facing upward shall have the lens 
adequately guarded to prevent contact by any person.
    (5) Fountains. All electric equipment, including power supply 
cords, operating at more than 15 volts and used with fountains shall be 
protected by ground-fault circuit interrupters.
    (k) Carnivals, circuses, fairs, and similar events. This paragraph 
covers the installation of portable wiring and equipment, including 
wiring in or on all structures, for carnivals, circuses, exhibitions, 
fairs, traveling attractions, and similar events.
    (1) Protection of electric equipment. Electric equipment and wiring 
methods in or on rides, concessions, or other units shall be provided 
with mechanical protection where such equipment or wiring methods are 
subject to physical damage.
    (2) Installation. (i) Services shall be installed in accordance 
with applicable requirements of this subpart, and, in addition, shall 
comply with the following:
    (A) Service equipment may not be installed in a location that is 
accessible to unqualified persons, unless the equipment is lockable; 
and
    (B) Service equipment shall be mounted on solid backing and 
installed so as to be protected from the weather, unless the equipment 
is of weatherproof construction.
    (ii) Amusement rides and amusement attractions shall be maintained 
not less than 4.57 m (15 ft) in any direction from overhead conductors 
operating at 600 volts or less, except for the conductors supplying the 
amusement ride or attraction. Amusement rides or attractions may not be 
located under or within 4.57 m (15 ft) horizontally of conductors 
operating in excess of 600 volts.
    (iii) Flexible cords and cables shall be listed for extra-hard 
usage. When used outdoors, flexible cords and cables shall also be 
listed for wet locations and shall be sunlight resistant.
    (iv) Single conductor cable shall be size No. 2 or larger.
    (v) Open conductors are prohibited except as part of a listed 
assembly or festoon lighting installed in accordance with Sec.  
1910.304(c).
    (vi) Flexible cords and cables shall be continuous without splice 
or tap between boxes or fittings. Cord connectors may not be laid on 
the ground unless listed for wet locations. Connectors and cable 
connections may not be placed in audience traffic paths or within areas 
accessible to the public unless guarded.
    (vii) Wiring for an amusement ride, attraction, tent, or similar 
structure may not be supported by another ride or structure unless 
specifically identified for the purpose.
    (viii) Flexible cords and cables run on the ground, where 
accessible to the public, shall be covered with approved nonconductive 
mats. Cables and mats shall be arranged so as not to present a tripping 
hazard.
    (ix) A box or fitting shall be installed at each connection point, 
outlet, switch point, or junction point.
    (3) Inside tents and concessions. Electrical wiring for temporary 
lighting, where installed inside of tents and concessions, shall be 
securely installed, and, where subject to physical damage, shall be 
provided with mechanical protection. All temporary lamps for general 
illumination shall be protected from accidental breakage by a suitable 
fixture or lampholder with a guard.
    (4) Portable distribution and termination boxes. Employers may only 
use portable distribution and termination boxes that meet the following 
requirements:
    (i) Boxes shall be designed so that no live parts are exposed to 
accidental contact. Where installed outdoors, the box shall be of 
weatherproof construction and mounted so that the bottom of the 
enclosure is not less than 152 mm (6 in.) above the ground;
    (ii) Busbars shall have an ampere rating not less than the 
overcurrent device supplying the feeder supplying the box. Busbar 
connectors shall be provided where conductors terminate directly on 
busbars;
    (iii) Receptacles shall have overcurrent protection installed 
within the box. The overcurrent protection may not exceed the ampere 
rating of the receptacle, except as permitted in Sec.  1910.305(j)(4) 
for motor loads;
    (iv) Where single-pole connectors are used, they shall comply with 
the following:
    (A) Where ac single-pole portable cable connectors are used, they 
shall be listed and of the locking type. Where paralleled sets of 
current-carrying single-pole separable connectors are provided as input 
devices, they shall be prominently labeled with a warning indicating 
the presence of internal parallel connections. The use of single-pole 
separable connectors shall comply with at least one of the following 
conditions:
    (1) Connection and disconnection of connectors are only possible 
where the supply connectors are interlocked to the source and it is not 
possible to connect or disconnect connectors when the supply is 
energized; or
    (2) Line connectors are of the listed sequential-interlocking type 
so that load connectors are connected in the following sequence:
    (i) Equipment grounding conductor connection;
    (ii) Grounded circuit-conductor connection, if provided; and
    (iii) Ungrounded conductor connection; and so that disconnection is 
in the reverse order; or
    (3) A caution notice is provided adjacent to the line connectors 
indicating that plug connection must be in the following sequence:
    (i) Equipment grounding conductor connection;
    (ii) Grounded circuit-conductor connection, if provided; and
    (iii) Ungrounded conductor connection; and indicating that 
disconnection is in the reverse order; and
    (B) Single-pole separable connectors used in portable professional 
motion picture and television equipment may be interchangeable for ac 
or dc use or for different current ratings on the same premises only if 
they are listed for ac/dc use and marked to identify the system to 
which they are connected;
    (v) Overcurrent protection of equipment and conductors shall be 
provided; and
    (vi) The following equipment connected to the same source shall be 
bonded:
    (A) Metal raceways and metal sheathed cable;
    (B) Metal enclosures of electrical equipment; and
    (C) Metal frames and metal parts of rides, concessions, trailers, 
trucks, or other equipment that contain or support electrical 
equipment.
    (5) Disconnecting means. (i) Each ride and concession shall be 
provided with a fused disconnect switch or circuit breaker located 
within sight and within 1.83 m (6 ft) of the operator's station.
    (ii) The disconnecting means shall be readily accessible to the 
operator, including when the ride is in operation.
    (iii) Where accessible to unqualified persons, the enclosure for 
the switch or circuit breaker shall be of the lockable type.
    (iv) A shunt trip device that opens the fused disconnect or circuit 
breaker when a switch located in the ride operator's console is closed 
is a permissible method of opening the circuit.

Sec.  1910.307  Hazardous (classified) locations.

    (a) Scope--(1) Applicability. This section covers the requirements 
for electric equipment and wiring in locations that are classified 
depending on the properties of the flammable vapors, liquids or gases, 
or combustible dusts or fibers that may be present therein and the 
likelihood that a flammable or combustible concentration or quantity is 
present. Hazardous (classified) locations may be found in occupancies 
such as, but not limited to, the following: aircraft hangars, gasoline 
dispensing and service stations, bulk storage plants for gasoline or 
other volatile flammable liquids, paint-finishing process plants, 
health care facilities, agricultural or other facilities where 
excessive combustible dusts may be present, marinas, boat yards, and 
petroleum and chemical processing plants. Each room, section or area 
shall be considered individually in determining its classification.
    (2) Classifications. (i) These hazardous (classified) locations are 
assigned the following designations:
    (A) Class I, Division 1
    (B) Class I, Division 2
    (C) Class I, Zone 0
    (D) Class I, Zone 1
    (E) Class I, Zone 2
    (F) Class II, Division 1
    (G) Class II, Division 2
    (H) Class III, Division 1
    (I) Class III, Division 2
    (ii) For definitions of these locations, see Sec.  1910.399.
    (3) Other sections of this subpart. All applicable requirements in 
this subpart apply to hazardous (classified) locations unless modified 
by provisions of this section.
    (4) Division and zone classification. In Class I locations, an 
installation must be classified as using the division classification 
system meeting paragraphs (c), (d), (e), and (f) of this section or 
using the zone classification system meeting paragraph (g) of this 
section. In Class II and Class III locations, an installation must be 
classified using the division classification system meeting paragraphs 
(c), (d), (e), and (f) of this section.
    (b) Documentation. All areas designated as hazardous (classified) 
locations under the Class and Zone system and areas designated under 
the Class and Division system established after August 13, 2007 shall 
be properly documented. This documentation shall be available to those 
authorized to design, install, inspect, maintain, or operate electric 
equipment at the location.
    (c) Electrical installations. Equipment, wiring methods, and 
installations of equipment in hazardous (classified) locations shall be 
intrinsically safe, approved for the hazardous (classified) location, 
or safe for the hazardous (classified) location. Requirements for each 
of these options are as follows:
    (1) Intrinsically safe. Equipment and associated wiring approved as 
intrinsically safe is permitted in any hazardous (classified) location 
for which it is approved;
    (2) Approved for the hazardous (classified) location. (i) Equipment 
shall be approved not only for the class of location, but also for the 
ignitable or combustible properties of the specific gas, vapor, dust, 
or fiber that will be present.

    Note to paragraph (c)(2)(i) of this section: NFPA 70, the 
National Electrical Code, lists or defines hazardous gases, vapors, 
and dusts by "Groups" characterized by their ignitable or 
combustible properties.

    (ii) Equipment shall be marked to show the class, group, and 
operating temperature or temperature range, based on operation in a 40-
degree C ambient, for which it is approved. The temperature marking may 
not exceed the ignition temperature of the specific gas or vapor to be 
encountered. However, the following provisions modify this marking 
requirement for specific equipment:
    (A) Equipment of the nonheat-producing type, such as junction 
boxes, conduit, and fittings, and equipment of the heat-producing type 
having a maximum temperature not more than 100[deg] C (212[deg] F) need 
not have a marked operating temperature or temperature range;
    (B) Fixed lighting fixtures marked for use in Class I, Division 2 
or Class II, Division 2 locations only need not be marked to indicate 
the group;
    (C) Fixed general-purpose equipment in Class I locations, other 
than lighting fixtures, that is acceptable for use in Class I, Division 
2 locations need not be marked with the class, group, division, or 
operating temperature;
    (D) Fixed dust-tight equipment, other than lighting fixtures, that 
is acceptable for use in Class II, Division 2 and Class III locations 
need not be marked with the class, group, division, or operating 
temperature; and
    (E) Electric equipment suitable for ambient temperatures exceeding 
40[deg] C (104[deg] F) shall be marked with both the maximum ambient 
temperature and the operating temperature or temperature range at that 
ambient temperature; and
    (3) Safe for the hazardous (classified) location. Equipment that is 
safe for the location shall be of a type and design that the employer 
demonstrates will provide protection from the hazards arising from the 
combustibility and flammability of vapors, liquids, gases, dusts, or 
fibers involved.

    Note to paragraph (c)(3) of this section: The National 
Electrical Code, NFPA 70, contains guidelines for determining the 
type and design of equipment and installations that will meet this 
requirement. Those guidelines address electric wiring, equipment, 
and systems installed in hazardous (classified) locations and 
contain specific provisions for the following: wiring methods, 
wiring connections; conductor insulation, flexible cords, sealing 
and drainage, transformers, capacitors, switches, circuit breakers, 
fuses, motor controllers, receptacles, attachment plugs, meters, 
relays, instruments, resistors, generators, motors, lighting 
fixtures, storage battery charging equipment, electric cranes, 
electric hoists and similar equipment, utilization equipment, 
signaling systems, alarm systems, remote control systems, local loud 
speaker and communication systems, ventilation piping, live parts, 
lightning surge protection, and grounding.

    (d) Conduits. All conduits shall be threaded and shall be made 
wrench-tight. Where it is impractical to make a threaded joint tight, a 
bonding jumper shall be utilized.
    (e) Equipment in Division 2 locations. Equipment that has been 
approved for a Division 1 location may be installed in a Division 2 
location of the same class and group. General-purpose equipment or 
equipment in general-purpose enclosures may be installed in Division 2 
locations if the employer can demonstrate that the equipment does not 
constitute a source of ignition under normal operating conditions.
    (f) Protection techniques. The following are acceptable protection 
techniques for electric and electronic equipment in hazardous 
(classified) locations.
    (1) Explosionproof apparatus. This protection technique is 
permitted for equipment in the Class I, Division 1 and 2 locations for 
which it is approved.
    (2) Dust ignitionproof. This protection technique is permitted for 
equipment in the Class II, Division 1 and 2 locations for which it is approved.
    (3) Dust-tight. This protection technique is permitted for 
equipment in the Class II, Division 2 and Class III locations for which 
it is approved.
    (4) Purged and pressurized. This protection technique is permitted 
for equipment in any hazardous (classified) location for which it is 
approved.
    (5) Nonincendive circuit. This protection technique is permitted 
for equipment in Class I, Division 2; Class II, Division 2; or Class 
III, Division 1or 2 locations.
    (6) Nonincendive equipment. This protection technique is permitted 
for equipment in Class I, Division 2; Class II, Division 2; or Class 
III, Division 1 or 2 locations.
    (7) Nonincendive component. This protection technique is permitted 
for equipment in Class I, Division 2; Class II, Division 2; or Class 
III, Division 1 or 2 locations.
    (8) Oil immersion. This protection technique is permitted for 
current-interrupting contacts in Class I, Division 2 locations as 
described in the Subpart.
    (9) Hermetically sealed. This protection technique is permitted for 
equipment in Class I, Division 2; Class II, Division 2; and Class III, 
Division 1 or 2 locations.
    (10) Other protection techniques. Any other protection technique 
that meets paragraph (c) of this section is acceptable in any hazardous 
(classified) location.
    (g) Class I, Zone 0, 1, and 2 locations--(1) Scope. Employers may 
use the zone classification system as an alternative to the division 
classification system for electric and electronic equipment and wiring 
for all voltage in Class I, Zone 0, Zone 1, and Zone 2 hazardous 
(classified) locations where fire or explosion hazards may exist due to 
flammable gases, vapors, or liquids.
    (2) Location and general requirements. (i) Locations shall be 
classified depending on the properties of the flammable vapors, 
liquids, or gases that may be present and the likelihood that a 
flammable or combustible concentration or quantity is present. Where 
pyrophoric materials are the only materials used or handled, these 
locations need not be classified.
    (ii) Each room, section, or area shall be considered individually 
in determining its classification.
    (iii) All threaded conduit shall be threaded with an NPT (National 
(American) Standard Pipe Taper) standard conduit cutting die that 
provides \3/4\-in. taper per foot. The conduit shall be made wrench 
tight to prevent sparking when fault current flows through the conduit 
system and to ensure the explosionproof or flameproof integrity of the 
conduit system where applicable.
    (iv) Equipment provided with threaded entries for field wiring 
connection shall be installed in accordance with paragraph 
(g)(2)(iv)(A) or (g)(2)(iv)(B) of this section.
    (A) For equipment provided with threaded entries for NPT threaded 
conduit or fittings, listed conduit, conduit fittings, or cable 
fittings shall be used.
    (B) For equipment with metric threaded entries, such entries shall 
be identified as being metric, or listed adaptors to permit connection 
to conduit of NPT-threaded fittings shall be provided with the 
equipment. Adapters shall be used for connection to conduit or NPT-
threaded fittings.
    (3) Protection techniques. One or more of the following protection 
techniques shall be used for electric and electronic equipment in 
hazardous (classified) locations classified under the zone 
classification system.
    (i) Flameproof "d"--This protection technique is permitted for 
equipment in the Class I, Zone 1 locations for which it is approved.
    (ii) Purged and pressurized--This protection technique is permitted 
for equipment in the Class I, Zone 1 or Zone 2 locations for which it 
is approved.
    (iii) Intrinsic safety--This protection technique is permitted for 
equipment in the Class I, Zone 0 or Zone 1 locations for which it is 
approved.
    (iv) Type of protection "n"--This protection technique is 
permitted for equipment in the Class I, Zone 2 locations for which it 
is approved. Type of protection "n" is further subdivided into nA, 
nC, and nR.
    (v) Oil Immersion "o"--This protection technique is permitted for 
equipment in the Class I, Zone 1 locations for which it is approved.
    (vi) Increased safety "e"--This protection technique is permitted 
for equipment in the Class I, Zone 1 locations for which it is 
approved.
    (vii) Encapsulation "m"--This protection technique is permitted 
for equipment in the Class I, Zone 1 locations for which it is 
approved.
    (viii) Powder Filling "q"--This protection technique is permitted 
for equipment in the Class I, Zone 1 locations for which it is 
approved.
    (4) Special precaution. Paragraph (g) of this section requires 
equipment construction and installation that will ensure safe 
performance under conditions of proper use and maintenance.
    (i) Classification of areas and selection of equipment and wiring 
methods shall be under the supervision of a qualified registered 
professional engineer.
    (ii) In instances of areas within the same facility classified 
separately, Class I, Zone 2 locations may abut, but not overlap, Class 
I, Division 2 locations. Class I, Zone 0 or Zone 1 locations may not 
abut Class I, Division 1 or Division 2 locations.
    (iii) A Class I, Division 1 or Division 2 location may be 
reclassified as a Class I, Zone 0, Zone 1, or Zone 2 location only if 
all of the space that is classified because of a single flammable gas 
or vapor source is reclassified.

    Note to paragraph (g)(4) of this section: Low ambient conditions 
require special consideration. Electric equipment depending on the 
protection techniques described by paragraph (g)(3)(i) of this 
section may not be suitable for use at temperatures lower than -20 
[deg]C (-4 [deg]F) unless they are approved for use at lower 
temperatures. However, at low ambient temperatures, flammable 
concentrations of vapors may not exist in a location classified 
Class I, Zone 0, 1, or 2 at normal ambient temperature.

    (5) Listing and marking. (i) Equipment that is listed for a Zone 0 
location may be installed in a Zone 1 or Zone 2 location of the same 
gas or vapor. Equipment that is listed for a Zone 1 location may be 
installed in a Zone 2 location of the same gas or vapor.
    (ii) Equipment shall be marked in accordance with paragraph 
(g)(5)(ii)(A) and (g)(5)(ii)(B) of this section, except as provided in 
(g)(5)(ii)(C).
    (A) Equipment approved for Class I, Division 1 or Class 1, Division 
2 shall, in addition to being marked in accordance with (c)(2)(ii), be 
marked with the following:
    (1) Class I, Zone 1 or Class I, Zone 2 (as applicable);
    (2) Applicable gas classification groups; and
    (3) Temperature classification; or
    (B) Equipment meeting one or more of the protection techniques 
described in paragraph (g)(3) of this section shall be marked with the 
following in the order shown:
    (1) Class, except for intrinsically safe apparatus;
    (2) Zone, except for intrinsically safe apparatus;
    (3) Symbol "AEx;"
    (4) Protection techniques;
    (5) Applicable gas classification groups; and
    (6) Temperature classification, except for intrinsically safe 
apparatus.

    Note to paragraph (g)(5)(ii)(B) of this section: An example of 
such a required marking is "Class I, Zone 0, AEx ia IIC T6." See 
Figure S-1 for an explanation of this marking.

    (C) Equipment that the employer demonstrates will provide 
protection from the hazards arising from the flammability of the gas or 
vapor and the zone of location involved and will be recognized as 
providing such protection by employees need not be marked.

    Note to paragraph (g)(5)(ii)(C) of this section: The National 
Electrical Code, NFPA 70, contains guidelines for determining the 
type and design of equipment and installations that will meet this 
provision.

[GRAPHIC] [TIFF OMITTED] TR14FE07.000

Sec.  1910.308  Special systems.

    (a) Systems over 600 volts, nominal. This paragraph covers the 
general requirements for all circuits and equipment operated at over 
600 volts.
    (1) Aboveground wiring methods. (i) Aboveground conductors shall be 
installed in rigid metal conduit, in intermediate metal conduit, in 
electrical metallic tubing, in rigid nonmetallic conduit, in cable 
trays, as busways, as cablebus, in other identified raceways, or as 
open runs of metal-clad cable suitable for the use and purpose. In 
locations accessible to qualified persons only, open runs of Type MV 
cables, bare conductors, and bare busbars are also permitted. Busbars 
shall be either copper or aluminum. Open runs of insulated wires and 
cables having a bare lead sheath or a braided outer covering shall be 
supported in a manner designed to prevent physical damage to the braid 
or sheath.
    (ii) Conductors emerging from the ground shall be enclosed in 
approved raceways.
    (2) Braid-covered insulated conductors--open installations. The 
braid on open runs of braid-covered insulated conductors shall be flame 
retardant or shall have a flame-retardant saturant applied after 
installation. This treated braid covering shall be stripped back a safe 
distance at conductor terminals, according to the operating voltage.
    (3) Insulation shielding. (i) Metallic and semiconductor insulation 
shielding components of shielded cables shall be removed for a distance 
dependent on the circuit voltage and insulation. Stress reduction means 
shall be provided at all terminations of factory-applied shielding.
    (ii) Metallic shielding components such as tapes, wires, or braids, 
or combinations thereof, and their associated conducting and 
semiconducting components shall be grounded.
    (4) Moisture or mechanical protection for metal-sheathed cables. 
Where cable conductors emerge from a metal sheath and where protection 
against moisture or physical damage is necessary, the insulation of the 
conductors shall be protected by a cable sheath terminating device.
    (5) Interrupting and isolating devices. (i) Circuit breaker 
installations located indoors shall consist of metal-enclosed units or 
fire-resistant cell-mounted units. In locations accessible only to 
qualified employees, open mounting of circuit breakers is permitted. A 
means of indicating the open and closed position of circuit breakers 
shall be provided.
    (ii) Where fuses are used to protect conductors and equipment, a 
fuse shall be placed in each ungrounded conductor. Two power fuses may 
be used in parallel to protect the same load, if both fuses have 
identical ratings, and if both fuses are installed in an identified 
common mounting with electrical connections that will divide the 
current equally. Power fuses of the vented type may not be used 
indoors, underground, or in metal enclosures unless identified for the 
use.
    (iii) Fused cutouts installed in buildings or transformer vaults 
shall be of a type identified for the purpose. Distribution cutouts may 
not be used indoors, underground, or in metal enclosures. They shall be 
readily accessible for fuse replacement.
    (iv) Where fused cutouts are not suitable to interrupt the circuit 
manually while carrying full load, an approved means shall be installed 
to interrupt the entire load. Unless the fused cutouts are interlocked 
with the switch to prevent opening of the cutouts under load, a 
conspicuous sign shall be placed at such cutouts reading: "WARNING--DO 
NOT OPERATE UNDER LOAD."
    (v) Suitable barriers or enclosures shall be provided to prevent 
contact with nonshielded cables or energized parts of oil-filled 
cutouts.
    (vi) Load interrupter switches may be used only if suitable fuses 
or circuits are used in conjunction with these devices to interrupt 
fault currents.
    (A) Where these devices are used in combination, they shall be 
coordinated electrically so that they will safely withstand the effects 
of closing, carrying, or interrupting all possible currents up to the 
assigned maximum short-circuit rating.
    (B) Where more than one switch is installed with interconnected 
load terminals to provide for alternate connection to different supply 
conductors, each switch shall be provided with a conspicuous sign 
reading: "WARNING--SWITCH MAY BE ENERGIZED BY BACKFEED."
    (vii) A means (for example, a fuseholder and fuse designed for the 
purpose) shall be provided to completely isolate equipment for 
inspection and repairs. Isolating means that are not designed to 
interrupt the load current of the circuit shall be either interlocked 
with an approved circuit interrupter or provided with a sign warning 
against opening them under load.
    (6) Mobile and portable equipment. (i) A metallic enclosure shall 
be provided on the mobile machine for enclosing the terminals of the 
power cable. The enclosure shall include provisions for a solid 
connection for the grounding terminal to effectively ground the machine 
frame. The method of cable termination used shall prevent any strain or 
pull on the cable from stressing the electrical connections. The 
enclosure shall have provision for locking so only authorized qualified 
persons may open it and shall be marked with a sign warning of the 
presence of energized parts.
    (ii) All energized switching and control parts shall be enclosed in 
effectively grounded metal cabinets or enclosures. Circuit breakers and 
protective equipment shall have the operating means projecting through 
the metal cabinet or enclosure so these units can be reset without 
locked doors being opened. Enclosures and metal cabinets shall be 
locked so that only authorized qualified persons have access and shall 
be marked with a sign warning of the presence of energized parts. 
Collector ring assemblies on revolving-type machines (shovels, 
draglines, etc.) shall be guarded.
    (7) Tunnel installations. This paragraph applies to installation 
and use of high-voltage power distribution and utilization equipment 
that is portable or mobile, such as substations, trailers, cars, mobile 
shovels, draglines, hoists, drills, dredges, compressors, pumps, 
conveyors, and underground excavators.
    (i) Conductors in tunnels shall be installed in one or more of the 
following:
    (A) Metal conduit or other metal raceway;
    (B) Type MC cable; or
    (C) Other approved multiconductor cable.
    (ii) Multiconductor portable cable may supply mobile equipment.
    (iii) Conductors and cables shall also be so located or guarded as 
to protect them from physical damage. An equipment grounding conductor 
shall be run with circuit conductors inside the metal raceway or inside 
the multiconductor cable jacket. The equipment grounding conductor may 
be insulated or bare.
    (iv) Bare terminals of transformers, switches, motor controllers, 
and other equipment shall be enclosed to prevent accidental contact 
with energized parts.
    (v) Enclosures for use in tunnels shall be drip-proof, 
weatherproof, or submersible as required by the environmental 
conditions.
    (vi) Switch or contactor enclosures may not be used as junction 
boxes or raceways for conductors feeding through or tapping off to 
other switches, unless special designs are used to provide adequate 
space for this purpose.
    (vii) A disconnecting means that simultaneously opens all 
ungrounded conductors shall be installed at each transformer or motor 
location.
    (viii) All nonenergized metal parts of electric equipment and metal 
raceways and cable sheaths shall be effectively grounded and bonded to 
all metal pipes and rails at the portal and at intervals not exceeding 
305 m (1000 ft) throughout the tunnel.
    (b) Emergency power systems. This paragraph applies to circuits, 
systems, and equipment intended to supply power for illumination and 
special loads in the event of failure of the normal supply.
    (1) Wiring methods. Emergency circuit wiring shall be kept entirely 
independent of all other wiring and equipment and may not enter the 
same raceway, cable, box, or cabinet or other wiring except either 
where common circuit elements suitable for the purpose are required, or 
for transferring power from the normal to the emergency source.
    (2) Emergency illumination. Emergency illumination shall include 
all required means of egress lighting, illuminated exit signs, and all 
other lights necessary to provide illumination. Where emergency 
lighting is necessary, the system shall be so arranged that the failure 
of any individual lighting element, such as the burning out of a light 
bulb, cannot leave any space in total darkness.
    (3) Signs. (i) A sign shall be placed at the service entrance 
equipment indicating the type and location of on-site emergency power 
sources. However, a sign is not required for individual unit equipment.
    (ii) Where the grounded circuit conductor connected to the 
emergency source is connected to a grounding electrode conductor at a 
location remote from the emergency source, there shall be a sign at the 
grounding location that shall identify all emergency and normal sources 
connected at that location.
    (c) Class 1, Class 2, and Class 3 remote control, signaling, and 
power-limited circuits--(1) Classification. Class 1, Class 2, and Class 
3 remote control, signaling, or power-limited circuits are 
characterized by their usage and electrical power limitation that 
differentiates them from light and power circuits. These circuits are 
classified in accordance with their respective voltage and power 
limitations as summarized in paragraphs (c)(1)(i) through (c)(1)(iii) 
of this section.
    (i) A Class 1 power-limited circuit shall be supplied from a source 
having a rated output of not more than 30 volts and 1000 volt-amperes.
    (ii) A Class 1 remote control circuit or a Class 1 signaling 
circuit shall have a voltage not exceeding 600 volts; however, the 
power output of the source need not be limited.
    (iii) The power source for a Class 2 or Class 3 circuit shall be 
listed equipment marked as a Class 2 or Class 3 power source, except as 
follows:
    (A) Thermocouples do not require listing as a Class 2 power source; 
and
    (B) A dry cell battery is considered an inherently limited Class 2 
power source, provided the voltage is 30 volts or less and the capacity 
is less than or equal to that available from series-connected No. 6 
carbon zinc cells.
    (2) Marking. A Class 2 or Class 3 power supply unit shall be 
durably marked where plainly visible to indicate the class of supply 
and its electrical rating.
    (3) Separation from conductors of other circuits. Cables and 
conductors of Class 2 and Class 3 circuits may not be placed in any 
cable, cable tray, compartment, enclosure, manhole, outlet box, device 
box, raceway, or similar fitting with conductors of electric light, 
power, Class 1, nonpower-limited fire alarm circuits, and medium power 
network-powered broadband communications cables unless a barrier or 
other equivalent form of protection against contact is employed.
    (d) Fire alarm systems--(1) Classifications. Fire alarm circuits 
shall be classified either as nonpower limited or power limited.
    (2) Power sources. The power sources for use with fire alarm 
circuits shall be either power limited or nonpower limited as follows:
    (i) The power source of nonpower-limited fire alarm (NPLFA) 
circuits shall have an output voltage of not more than 600 volts, 
nominal; and
    (ii) The power source for a power-limited fire alarm (PLFA) circuit 
shall be listed equipment marked as a PLFA power source.
    (3) Separation from conductors of other circuits. (i) Nonpower-
limited fire alarm circuits and Class 1 circuits may occupy the same 
enclosure, cable, or raceway provided all conductors are insulated for 
maximum voltage of any conductor within the enclosure, cable, or 
raceway. Power supply and fire alarm circuit conductors are permitted 
in the same enclosure, cable, or raceway only if connected to the same 
equipment.
    (ii) Power-limited circuit cables and conductors may not be placed 
in any cable, cable tray, compartment, enclosure, outlet box, raceway, 
or similar fitting with conductors of electric light, power, Class 1, 
nonpower-limited fire alarm circuit conductors, or medium power 
network-powered broadband communications circuits.
    (iii) Power-limited fire alarm circuit conductors shall be 
separated at least 50.8 mm (2 in.) from conductors of any electric 
light, power, Class 1, nonpower-limited fire alarm, or medium power 
network-powered broadband communications circuits unless a special and 
equally protective method of conductor separation is employed.
    (iv) Conductors of one or more Class 2 circuits are permitted 
within the same cable, enclosure, or raceway with conductors of power-
limited fire alarm circuits provided that the insulation of Class 2 
circuit conductors in the cable, enclosure, or raceway is at least that 
needed for the power-limited fire alarm circuits.
    (4) Identification. Fire alarm circuits shall be identified at 
terminal and junction locations in a manner that will prevent 
unintentional interference with the signaling circuit during testing 
and servicing. Power-limited fire alarm circuits shall be durably 
marked as such where plainly visible at terminations.
    (e) Communications systems. This paragraph applies to central-
station-connected and non-central-station-connected telephone circuits, 
radio and television receiving and transmitting equipment, including 
community antenna television and radio distribution systems, telegraph, 
district messenger, and outside wiring for fire and burglar alarm, and 
similar central station systems. These installations need not comply 
with the provisions of Sec.  1910.303 through Sec.  1910.308(d), except 
for Sec.  1910.304(c)(1) and Sec.  1910.307.
    (1) Protective devices. (i) A listed primary protector shall be 
provided on each circuit run partly or entirely in aerial wire or 
aerial cable not confined within a block.
    (ii) A listed primary protector shall be also provided on each 
aerial or underground circuit when the location of the circuit within 
the block containing the building served allows the circuit to be 
exposed to accidental contact with electric light or power conductors 
operating at over 300 volts to ground.
    (iii) In addition, where there exists a lightning exposure, each 
interbuilding circuit on premises shall be protected by a listed 
primary protector at each end of the interbuilding circuit.
    (2) Conductor location. (i) Lead-in or aerial-drop cables from a 
pole or other support, including the point of initial attachment to a 
building or structure, shall be kept away from electric light, power, 
Class 1, or nonpower-limited fire alarm circuit conductors so as to 
avoid the possibility of accidental contact.
    (ii) A separation of at least 1.83 m (6 ft) shall be maintained 
between communications wires and cables on buildings and lightning 
conductors.
    (iii) Where communications wires and cables and electric light or 
power conductors are supported by the same pole or run parallel to each 
other in-span, the following conditions shall be met:
    (A) Where practicable, communication wires and cables on poles 
shall be located below the electric light or power conductors; and
    (B) Communications wires and cables may not be attached to a 
crossarm that carries electric light or power conductors.
    (iv) Indoor communications wires and cables shall be separated at 
least 50.8 mm (2 in.) from conductors of any electric light, power, 
Class 1, nonpower-limited fire alarm, or medium power network-powered 
broadband communications circuits, unless a special and equally 
protective method of conductor separation, identified for the purpose, 
is employed.
    (3) Equipment location. Outdoor metal structures supporting 
antennas, as well as self-supporting antennas such as vertical rods or 
dipole structures, shall be located as far away from overhead 
conductors of electric light and power circuits of over 150 volts to 
ground as necessary to prevent the antenna or structure from falling 
into or making accidental contact with such circuits.
    (4) Grounding. (i) If exposed to contact with electric light and 
power conductors, the metal sheath of aerial cables entering buildings 
shall be grounded or shall be interrupted close to the entrance to the 
building by an insulating joint or equivalent device. Where protective 
devices are used, they shall be grounded in an approved manner.
    (ii) Masts and metal structures supporting antennas shall be 
permanently and effectively grounded without splice or connection in 
the grounding conductor.
    (iii) Transmitters shall be enclosed in a metal frame or grill or 
separated from the operating space by a barrier, all metallic parts of 
which are effectively connected to ground. All external metal handles 
and controls accessible to the operating personnel shall be effectively 
grounded. Unpowered equipment and enclosures are considered to be 
grounded where connected to an attached coaxial cable with an 
effectively grounded metallic shield.
    (f) Solar photovoltaic systems. This paragraph covers solar 
photovoltaic systems that can be interactive with other electric power 
production sources or can stand alone with or without electrical energy 
storage such as batteries. These systems may have ac or dc output for 
utilization.
    (1) Conductors of different systems. Photovoltaic source circuits 
and photovoltaic output circuits may not be contained in the same 
raceway, cable tray, cable, outlet box, junction box, or similar 
fitting as feeders or branch circuits of other systems, unless the 
conductors of the different systems are separated by a partition or are 
connected together.
    (2) Disconnecting means. Means shall be provided to disconnect all 
current-carrying conductors of a photovoltaic power source from all 
other conductors in a building or other structure. Where a circuit 
grounding connection is not designed to be automatically interrupted as 
part of the ground-fault protection system, a switch or circuit breaker 
used as disconnecting means may not have a pole in the grounded 
conductor.
    (g) Integrated electrical systems--(1) Scope. Paragraph (g) of this 
section covers integrated electrical systems, other than unit 
equipment, in which orderly shutdown is necessary to ensure safe 
operation. An integrated electrical system as used in this section 
shall be a unitized segment of an industrial wiring system where all of 
the following conditions are met:
    (i) An orderly shutdown process minimizes employee hazard and 
equipment damage;
    (ii) The conditions of maintenance and supervision ensure that only 
qualified persons will service the system; and
    (iii) Effective safeguards are established and maintained.
    (2) Location of overcurrent devices in or on premises. Overcurrent 
devices that are critical to integrated electrical systems need not be 
readily accessible to employees as required by Sec.  1910.304(f)(1)(iv) 
if they are located with mounting heights to ensure security from operation 
by nonqualified persons.

0
7. Section 1910.399 is revised to read as follows:


Sec.  1910.399  Definitions applicable to this subpart.

    Acceptable. An installation or equipment is acceptable to the 
Assistant Secretary of Labor, and approved within the meaning of this 
Subpart S:
    (1) If it is accepted, or certified, or listed, or labeled, or 
otherwise determined to be safe by a nationally recognized testing 
laboratory recognized pursuant to Sec.  1910.7; or
    (2) With respect to an installation or equipment of a kind that no 
nationally recognized testing laboratory accepts, certifies, lists, 
labels, or determines to be safe, if it is inspected or tested by 
another Federal agency, or by a State, municipal, or other local 
authority responsible for enforcing occupational safety provisions of 
the National Electrical Code, and found in compliance with the 
provisions of the National Electrical Code as applied in this subpart; 
or
    (3) With respect to custom-made equipment or related installations 
that are designed, fabricated for, and intended for use by a particular 
customer, if it is determined to be safe for its intended use by its 
manufacturer on the basis of test data which the employer keeps and 
makes available for inspection to the Assistant Secretary and his 
authorized representatives.
    Accepted. An installation is "accepted" if it has been inspected 
and found by a nationally recognized testing laboratory to conform to 
specified plans or to procedures of applicable codes.
    Accessible. (As applied to wiring methods.) Capable of being 
removed or exposed without damaging the building structure or finish, 
or not permanently closed in by the structure or finish of the 
building. (See "concealed" and "exposed.")
    Accessible. (As applied to equipment.) Admitting close approach; 
not guarded by locked doors, elevation, or other effective means. (See 
"Readily accessible.")
    Ampacity. The current, in amperes, that a conductor can carry 
continuously under the conditions of use without exceeding its 
temperature rating.
    Appliances. Utilization equipment, generally other than industrial, 
normally built in standardized sizes or types, that is installed or 
connected as a unit to perform one or more functions.
    Approved. Acceptable to the authority enforcing this subpart. The 
authority enforcing this subpart is the Assistant Secretary of Labor 
for Occupational Safety and Health. The definition of "acceptable" 
indicates what is acceptable to the Assistant Secretary of Labor, and 
therefore approved within the meaning of this subpart.
    Armored cable (Type AC). A fabricated assembly of insulated 
conductors in a flexible metallic enclosure.
    Askarel. A generic term for a group of nonflammable synthetic 
chlorinated hydrocarbons used as electrical insulating media. Askarels 
of various compositional types are used. Under arcing conditions, the 
gases produced, while consisting predominantly of noncombustible 
hydrogen chloride, can include varying amounts of combustible gases 
depending upon the askarel type.
    Attachment plug (Plug cap)(Cap). A device that, by insertion in a 
receptacle, establishes a connection between the conductors of the 
attached flexible cord and the conductors connected permanently to the 
receptacle.
    Automatic. Self-acting, operating by its own mechanism when 
actuated by some impersonal influence, as, for example, a change in 
current strength, pressure, temperature, or mechanical configuration.
    Bare conductor. See Conductor.
    Barrier. A physical obstruction that is intended to prevent contact 
with equipment or live parts or to prevent unauthorized access to a 
work area.
    Bathroom. An area including a basin with one or more of the 
following: a toilet, a tub, or a shower.
    Bonding (Bonded). The permanent joining of metallic parts to form 
an electrically conductive path that ensures electrical continuity and 
the capacity to conduct safely any current likely to be imposed.
    Bonding jumper. A conductor that assures the necessary electrical 
conductivity between metal parts required to be electrically connected.
    Branch circuit. The circuit conductors between the final 
overcurrent device protecting the circuit and the outlets.
    Building. A structure that stands alone or is cut off from 
adjoining structures by fire walls with all openings therein protected 
by approved fire doors.
    Cabinet. An enclosure designed either for surface or flush 
mounting, and provided with a frame, mat, or trim in which a swinging 
door or doors are or can be hung.
    Cable tray system. A unit or assembly of units or sections and 
associated fittings forming a rigid structural system used to securely 
fasten or support cables and raceways. Cable tray systems include 
ladders, troughs, channels, solid bottom trays, and other similar 
structures.
    Cablebus. An assembly of insulated conductors with fittings and 
conductor terminations in a completely enclosed, ventilated, protective 
metal housing.
    Cell line. An assembly of electrically interconnected electrolytic 
cells supplied by a source of direct current power.
    Cell line attachments and auxiliary equipment. Cell line 
attachments and auxiliary equipment include, but are not limited to, 
auxiliary tanks, process piping, ductwork, structural supports, exposed 
cell line conductors, conduits and other raceways, pumps, positioning 
equipment, and cell cutout or bypass electrical devices. Auxiliary 
equipment also includes tools, welding machines, crucibles, and other 
portable equipment used for operation and maintenance within the 
electrolytic cell line working zone. In the cell line working zone, 
auxiliary equipment includes the exposed conductive surfaces of 
ungrounded cranes and crane-mounted cell-servicing equipment.
    Center pivot irrigation machine. A multi-motored irrigation machine 
that revolves around a central pivot and employs alignment switches or 
similar devices to control individual motors.
    Certified. Equipment is "certified" if it bears a label, tag, or 
other record of certification that the equipment:
    (1) Has been tested and found by a nationally recognized testing 
laboratory to meet nationally recognized standards or to be safe for 
use in a specified manner; or
    (2) Is of a kind whose production is periodically inspected by a 
nationally recognized testing laboratory and is accepted by the 
laboratory as safe for its intended use.
    Circuit breaker. A device designed to open and close a circuit by 
nonautomatic means and to open the circuit automatically on a 
predetermined overcurrent without damage to itself when properly 
applied within its rating.
    Class I locations. Class I locations are those in which flammable 
gases or vapors are or may be present in the air in quantities 
sufficient to produce explosive or ignitable mixtures. Class I 
locations include the following:
    (1) Class I, Division 1. A Class I, Division 1 location is a 
location:
    (i) In which ignitable concentrations of flammable gases or vapors 
may exist under normal operating conditions; or
    (ii) In which ignitable concentrations of such gases or vapors may 
exist frequently because of repair or maintenance operations or because 
of leakage; or
    (iii) In which breakdown or faulty operation of equipment or 
processes might release ignitable concentrations of flammable gases or 
vapors, and might also cause simultaneous failure of electric 
equipment.

    Note to the definition of "Class I, Division 1:" This 
classification usually includes locations where volatile flammable 
liquids or liquefied flammable gases are transferred from one 
container to another; interiors of spray booths and areas in the 
vicinity of spraying and painting operations where volatile 
flammable solvents are used; locations containing open tanks or vats 
of volatile flammable liquids; drying rooms or compartments for the 
evaporation of flammable solvents; locations containing fat and oil 
extraction equipment using volatile flammable solvents; portions of 
cleaning and dyeing plants where flammable liquids are used; gas 
generator rooms and other portions of gas manufacturing plants where 
flammable gas may escape; inadequately ventilated pump rooms for 
flammable gas or for volatile flammable liquids; the interiors of 
refrigerators and freezers in which volatile flammable materials are 
stored in open, lightly stoppered, or easily ruptured containers; 
and all other locations where ignitable concentrations of flammable 
vapors or gases are likely to occur in the course of normal 
operations.

    (2) Class I, Division 2. A Class I, Division 2 location is a 
location:
    (i) In which volatile flammable liquids or flammable gases are 
handled, processed, or used, but in which the hazardous liquids, 
vapors, or gases will normally be confined within closed containers or 
closed systems from which they can escape only in the event of 
accidental rupture or breakdown of such containers or systems, or as a 
result of abnormal operation of equipment; or
    (ii) In which ignitable concentrations of gases or vapors are 
normally prevented by positive mechanical ventilation, and which might 
become hazardous through failure or abnormal operations of the 
ventilating equipment; or
    (iii) That is adjacent to a Class I, Division 1 location, and to 
which ignitable concentrations of gases or vapors might occasionally be 
communicated unless such communication is prevented by adequate 
positive-pressure ventilation from a source of clean air, and effective 
safeguards against ventilation failure are provided.

    Note to the definition of "Class I, Division 2:" This 
classification usually includes locations where volatile flammable 
liquids or flammable gases or vapors are used, but which would 
become hazardous only in case of an accident or of some unusual 
operating condition. The quantity of flammable material that might 
escape in case of accident, the adequacy of ventilating equipment, 
the total area involved, and the record of the industry or business 
with respect to explosions or fires are all factors that merit 
consideration in determining the classification and extent of each 
location.

    Piping without valves, checks, meters, and similar devices would 
not ordinarily introduce a hazardous condition even though used for 
flammable liquids or gases. Locations used for the storage of 
flammable liquids or liquefied or compressed gases in sealed 
containers would not normally be considered hazardous unless also 
subject to other hazardous conditions.

    Electrical conduits and their associated enclosures separated 
from process fluids by a single seal or barrier are classed as a 
Division 2 location if the outside of the conduit and enclosures is 
a nonhazardous location.

    (3) Class I, Zone 0. A Class I, Zone 0 location is a location in 
which one of the following conditions exists:
    (i) Ignitable concentrations of flammable gases or vapors are 
present continuously; or
    (ii) Ignitable concentrations of flammable gases or vapors are 
present for long periods of time.

    Note to the definition of "Class I, Zone 0:" As a guide in 
determining when flammable gases or vapors are present continuously 
or for long periods of time, refer to Recommended Practice for 
Classification of Locations for Electrical Installations of 
Petroleum Facilities Classified as Class I, Zone 0, Zone 1 or Zone 
2, API RP 505-1997; Electrical Apparatus for Explosive Gas 
Atmospheres, Classifications of Hazardous Areas, IEC 79-10-1995; 
Area Classification Code for Petroleum Installations, Model Code--
Part 15, Institute for Petroleum; and Electrical Apparatus for 
Explosive Gas Atmospheres, Classifications of Hazardous (Classified) 
Locations, ISA S12.24.01-1997.

    (4) Class I, Zone 1. A Class I, Zone 1 location is a location in 
which one of the following conditions exists:
    (i) Ignitable concentrations of flammable gases or vapors are 
likely to exist under normal operating conditions; or
    (ii) Ignitable concentrations of flammable gases or vapors may 
exist frequently because of repair or maintenance operations or because 
of leakage; or
    (iii) Equipment is operated or processes are carried on of such a 
nature that equipment breakdown or faulty operations could result in 
the release of ignitable concentrations of flammable gases or vapors 
and also cause simultaneous failure of electric equipment in a manner 
that would cause the electric equipment to become a source of ignition; 
or
    (iv) A location that is adjacent to a Class I, Zone 0 location from 
which ignitable concentrations of vapors could be communicated, unless 
communication is prevented by adequate positive pressure ventilation 
from a source of clean air and effective safeguards against ventilation 
failure are provided.
    (5) Class I, Zone 2. A Class I, Zone 2 location is a location in 
which one of the following conditions exists:
    (i) Ignitable concentrations of flammable gases or vapors are not 
likely to occur in normal operation and if they do occur will exist 
only for a short period; or
    (ii) Volatile flammable liquids, flammable gases, or flammable 
vapors are handled, processed, or used, but in which the liquids, 
gases, or vapors are normally confined within closed containers or 
closed systems from which they can escape only as a result of 
accidental rupture or breakdown of the containers or system or as the 
result of the abnormal operation of the equipment with which the 
liquids or gases are handled, processed, or used; or
    (iii) Ignitable concentrations of flammable gases or vapors 
normally are prevented by positive mechanical ventilation, but which 
may become hazardous as the result of failure or abnormal operation of 
the ventilation equipment; or
    (iv) A location that is adjacent to a Class I, Zone 1 location, 
from which ignitable concentrations of flammable gases or vapors could 
be communicated, unless such communication is prevented by adequate 
positive-pressure ventilation from a source of clean air, and effective 
safeguards against ventilation failure are provided.
    Class II locations. Class II locations are those that are hazardous 
because of the presence of combustible dust. Class II locations include 
the following:
    (1) Class II, Division 1. A Class II, Division 1 location is a 
location:
    (i) In which combustible dust is or may be in suspension in the air 
under normal operating conditions, in quantities sufficient to produce 
explosive or ignitable mixtures; or
    (ii) Where mechanical failure or abnormal operation of machinery or 
equipment might cause such explosive or ignitable mixtures to be 
produced, and might also provide a source of ignition through 
simultaneous failure of electric equipment, through operation of 
protection devices, or from other causes; or
    (iii) In which combustible dusts of an electrically conductive 
nature may be present.

    Note to the definition of "Class II, Division 1:" This 
classification may include areas of grain handling and processing 
plants, starch plants, sugar-pulverizing plants, malting
plants, hay-grinding plants, coal pulverizing plants, areas where 
metal dusts and powders are produced or processed, and other similar 
locations that contain dust producing machinery and equipment 
(except where the equipment is dust-tight or vented to the outside). 
These areas would have combustible dust in the air, under normal 
operating conditions, in quantities sufficient to produce explosive 
or ignitable mixtures. Combustible dusts that are electrically 
nonconductive include dusts produced in the handling and processing 
of grain and grain products, pulverized sugar and cocoa, dried egg 
and milk powders, pulverized spices, starch and pastes, potato and 
wood flour, oil meal from beans and seed, dried hay, and other 
organic materials which may produce combustible dusts when processed 
or handled. Dusts containing magnesium or aluminum are particularly 
hazardous, and the use of extreme caution is necessary to avoid 
ignition and explosion.

    (2) Class II, Division 2. A Class II, Division 2 location is a 
location where:
    (i) Combustible dust will not normally be in suspension in the air 
in quantities sufficient to produce explosive or ignitable mixtures, 
and dust accumulations will normally be insufficient to interfere with 
the normal operation of electric equipment or other apparatus, but 
combustible dust may be in suspension in the air as a result of 
infrequent malfunctioning of handling or processing equipment; and
    (ii) Resulting combustible dust accumulations on, in, or in the 
vicinity of the electric equipment may be sufficient to interfere with 
the safe dissipation of heat from electric equipment or may be 
ignitable by abnormal operation or failure of electric equipment.

    Note to the definition of "Class II, Division 2:" This 
classification includes locations where dangerous concentrations of 
suspended dust would not be likely, but where dust accumulations 
might form on or in the vicinity of electric equipment. These areas 
may contain equipment from which appreciable quantities of dust 
would escape under abnormal operating conditions or be adjacent to a 
Class II Division 1 location, as described above, into which an 
explosive or ignitable concentration of dust may be put into 
suspension under abnormal operating conditions.

    Class III locations. Class III locations are those that are 
hazardous because of the presence of easily ignitable fibers or 
flyings, but in which such fibers or flyings are not likely to be in 
suspension in the air in quantities sufficient to produce ignitable 
mixtures. Class III locations include the following:
    (1) Class III, Division 1. A Class III, Division 1 location is a 
location in which easily ignitable fibers or materials producing 
combustible flyings are handled, manufactured, or used.

    Note to the definition of "Class III, Division 1:" Such 
locations usually include some parts of rayon, cotton, and other 
textile mills; combustible fiber manufacturing and processing 
plants; cotton gins and cotton-seed mills; flax-processing plants; 
clothing manufacturing plants; woodworking plants, and 
establishments; and industries involving similar hazardous processes 
or conditions.
    Easily ignitable fibers and flyings include rayon, cotton 
(including cotton linters and cotton waste), sisal or henequen, 
istle, jute, hemp, tow, cocoa fiber, oakum, baled waste kapok, 
Spanish moss, excelsior, and other materials of similar nature.

    (2) Class III, Division 2. A Class III, Division 2 location is a 
location in which easily ignitable fibers are stored or handled, other 
than in the process of manufacture.
    Collector ring. An assembly of slip rings for transferring electric 
energy from a stationary to a rotating member.
    Competent Person. One who is capable of identifying existing and 
predictable hazards in the surroundings or working conditions that are 
unsanitary, hazardous, or dangerous to employees and who has 
authorization to take prompt corrective measures to eliminate them.
    Concealed. Rendered inaccessible by the structure or finish of the 
building. Wires in concealed raceways are considered concealed, even 
though they may become accessible by withdrawing them. (See Accessible. 
(As applied to wiring methods.))
    Conductor--(1) Bare. A conductor having no covering or electrical 
insulation whatsoever.
    (2) Covered. A conductor encased within material of composition or 
thickness that is not recognized by this subpart as electrical 
insulation.
    (3) Insulated. A conductor encased within material of composition 
and thickness that is recognized by this subpart as electrical 
insulation.
    Conduit body. A separate portion of a conduit or tubing system that 
provides access through one or more removable covers to the interior of 
the system at a junction of two or more sections of the system or at a 
terminal point of the system. Boxes such as FS and FD or larger cast or 
sheet metal boxes are not classified as conduit bodies.
    Controller. A device or group of devices that serves to govern, in 
some predetermined manner, the electric power delivered to the 
apparatus to which it is connected.
    Covered conductor. See Conductor.
    Cutout. (Over 600 volts, nominal.) An assembly of a fuse support 
with either a fuseholder, fuse carrier, or disconnecting blade. The 
fuseholder or fuse carrier may include a conducting element (fuse 
link), or may act as the disconnecting blade by the inclusion of a 
nonfusible member.
    Cutout box. An enclosure designed for surface mounting and having 
swinging doors or covers secured directly to and telescoping with the 
walls of the box proper. (See Cabinet.)
    Damp location. See Location.
    Dead front. Without live parts exposed to a person on the operating 
side of the equipment
    Deenergized. Free from any electrical connection to a source of 
potential difference and from electrical charge; not having a potential 
different from that of the earth.
    Device. A unit of an electrical system that is intended to carry 
but not utilize electric energy.
    Dielectric heating. The heating of a nominally insulating material 
due to its own dielectric losses when the material is placed in a 
varying electric field.
    Disconnecting means. A device, or group of devices, or other means 
by which the conductors of a circuit can be disconnected from their 
source of supply.
    Disconnecting (or Isolating) switch. (Over 600 volts, nominal.) A 
mechanical switching device used for isolating a circuit or equipment 
from a source of power.
    Electrolytic cell line working zone. The cell line working zone is 
the space envelope wherein operation or maintenance is normally 
performed on or in the vicinity of exposed energized surfaces of 
electrolytic cell lines or their attachments.
    Electrolytic cells. A tank or vat in which electrochemical 
reactions are caused by applying energy for the purpose of refining or 
producing usable materials.
    Enclosed. Surrounded by a case, housing, fence, or walls that will 
prevent persons from accidentally contacting energized parts.
    Enclosure. The case or housing of apparatus, or the fence or walls 
surrounding an installation to prevent personnel from accidentally 
contacting energized parts, or to protect the equipment from physical 
damage.
    Energized. Electrically connected to a source of potential 
difference.
    Equipment. A general term including material, fittings, devices, 
appliances, fixtures, apparatus, and the like, used as a part of, or in 
connection with, an electrical installation.
    Equipment grounding conductor. See Grounding conductor, equipment.
    Explosion-proof apparatus. Apparatus enclosed in a case that is 
capable of withstanding an explosion of a specified gas or vapor that 
may occur within it and of preventing the ignition of a specified gas 
or vapor surrounding the enclosure by sparks, flashes, or explosion of 
the gas or vapor within, and that operates at such an external temperature 
that it will not ignite a surrounding flammable atmosphere.
    Exposed. (As applied to live parts.) Capable of being inadvertently 
touched or approached nearer than a safe distance by a person. It is 
applied to parts not suitably guarded, isolated, or insulated. (See 
Accessible and Concealed.)
    Exposed. (As applied to wiring methods.) On or attached to the 
surface, or behind panels designed to allow access. (See Accessible. 
(As applied to wiring methods.))
    Exposed. (For the purposes of Sec.  1910.308(e).) Where the circuit 
is in such a position that in case of failure of supports or 
insulation, contact with another circuit may result.
    Externally operable. Capable of being operated without exposing the 
operator to contact with live parts.
    Feeder. All circuit conductors between the service equipment, the 
source of a separate derived system, or other power supply source and 
the final branch-circuit overcurrent device.
    Fitting. An accessory such as a locknut, bushing, or other part of 
a wiring system that is intended primarily to perform a mechanical 
rather than an electrical function.
    Fountain. Fountains, ornamental pools, display pools, and 
reflection pools.

    Note to the definition of "fountain:" This definition does not 
include drinking fountains.

    Fuse. (Over 600 volts, nominal.) An overcurrent protective device 
with a circuit opening fusible part that is heated and severed by the 
passage of overcurrent through it. A fuse comprises all the parts that 
form a unit capable of performing the prescribed functions. It may or 
may not be the complete device necessary to connect it into an 
electrical circuit.
    Ground. A conducting connection, whether intentional or accidental, 
between an electric circuit or equipment and the earth, or to some 
conducting body that serves in place of the earth.
    Grounded. Connected to the earth or to some conducting body that 
serves in place of the earth.
    Grounded, effectively. Intentionally connected to earth through a 
ground connection or connections of sufficiently low impedance and 
having sufficient current-carrying capacity to prevent the buildup of 
voltages that may result in undue hazards to connected equipment or to 
persons.
    Grounded conductor. A system or circuit conductor that is 
intentionally grounded.
    Grounding conductor. A conductor used to connect equipment or the 
grounded circuit of a wiring system to a grounding electrode or 
electrodes.
    Grounding conductor, equipment. The conductor used to connect the 
noncurrent-carrying metal parts of equipment, raceways, and other 
enclosures to the system grounded conductor, the grounding electrode 
conductor, or both, at the service equipment or at the source of a 
separately derived system.
    Grounding electrode conductor. The conductor used to connect the 
grounding electrode to the equipment grounding conductor, to the 
grounded conductor, or to both, of the circuits at the service 
equipment or at the source of a separately derived system.
    Ground-fault circuit-interrupter. A device intended for the 
protection of personnel that functions to deenergize a circuit or a 
portion of a circuit within an established period of time when a 
current to ground exceeds some predetermined value that is less than 
that required to operate the overcurrent protective device of the 
supply circuit.
    Guarded. Covered, shielded, fenced, enclosed, or otherwise 
protected by means of suitable covers, casings, barriers, rails, 
screens, mats, or platforms to remove the likelihood of approach to a 
point of danger or contact by persons or objects.
    Health care facilities. Buildings or portions of buildings in which 
medical, dental, psychiatric, nursing, obstetrical, or surgical care 
are provided.

    Note to the definition of "health care facilities:" Health 
care facilities include, but are not limited to, hospitals, nursing 
homes, limited care facilities, clinics, medical and dental offices, 
and ambulatory care centers, whether permanent or movable.

    Heating equipment. For the purposes of Sec.  1910.306(g), the term 
"heating equipment" includes any equipment used for heating purposes 
if heat is generated by induction or dielectric methods.
    Hoistway. Any shaftway, hatchway, well hole, or other vertical 
opening or space that is designed for the operation of an elevator or 
dumbwaiter.
    Identified (as applied to equipment). Approved as suitable for the 
specific purpose, function, use, environment, or application, where 
described in a particular requirement.

    Note to the definition of "identified:" Some examples of ways 
to determine suitability of equipment for a specific purpose, 
environment, or application include investigations by a nationally 
recognized testing laboratory (through listing and labeling), 
inspection agency, or other organization recognized under the 
definition of "acceptable."

    Induction heating. The heating of a nominally conductive material 
due to its own I\2\R losses when the material is placed in a varying 
electromagnetic field.
    Insulated. Separated from other conducting surfaces by a dielectric 
(including air space) offering a high resistance to the passage of 
current.
    Insulated conductor. See Conductor, Insulated.
    Interrupter switch. (Over 600 volts, nominal.) A switch capable of 
making, carrying, and interrupting specified currents.
    Irrigation Machine. An electrically driven or controlled machine, 
with one or more motors, not hand portable, and used primarily to 
transport and distribute water for agricultural purposes.
    Isolated. (As applied to location.) Not readily accessible to 
persons unless special means for access are used.
    Isolated power system. A system comprising an isolating transformer 
or its equivalent, a line isolation monitor, and its ungrounded circuit 
conductors.
    Labeled. Equipment is "labeled" if there is attached to it a 
label, symbol, or other identifying mark of a nationally recognized 
testing laboratory:
    (1) That makes periodic inspections of the production of such 
equipment, and
    (2) Whose labeling indicates compliance with nationally recognized 
standards or tests to determine safe use in a specified manner.
    Lighting outlet. An outlet intended for the direct connection of a 
lampholder, a lighting fixture, or a pendant cord terminating in a 
lampholder.
    Line-clearance tree trimming. The pruning, trimming, repairing, 
maintaining, removing, or clearing of trees or cutting of brush that is 
within 305 cm (10 ft) of electric supply lines and equipment.
    Listed. Equipment is "listed" if it is of a kind mentioned in a 
list that:
    (1) Is published by a nationally recognized laboratory that makes 
periodic inspection of the production of such equipment, and
    (2) States that such equipment meets nationally recognized 
standards or has been tested and found safe for use in a specified 
manner.
    Live parts. Energized conductive components.
    Location--(1) Damp location. Partially protected locations under 
canopies, marquees, roofed open porches, and like locations, and 
interior locations subject to moderate degrees of moisture, such as some 
basements, some barns, and some cold-storage warehouses.
    (2) Dry location. A location not normally subject to dampness or 
wetness. A location classified as dry may be temporarily subject to 
dampness or wetness, as in the case of a building under construction.
    (3) Wet location. Installations underground or in concrete slabs or 
masonry in direct contact with the earth, and locations subject to 
saturation with water or other liquids, such as vehicle-washing areas, 
and locations unprotected and exposed to weather.
    Medium voltage cable (Type MV). A single or multiconductor solid 
dielectric insulated cable rated 2001 volts or higher.
    Metal-clad cable (Type MC). A factory assembly of one or more 
insulated circuit conductors with or without optical fiber members 
enclosed in an armor of interlocking metal tape, or a smooth or 
corrugated metallic sheath.
    Mineral-insulated metal-sheathed cable (Type MI). Type MI, mineral-
insulated metal-sheathed, cable is a factory assembly of one or more 
conductors insulated with a highly compressed refractory mineral 
insulation and enclosed in a liquidtight and gastight continuous copper 
or alloy steel sheath.
    Mobile X-ray. X-ray equipment mounted on a permanent base with 
wheels or casters or both for moving while completely assembled.
    Motor control center. An assembly of one or more enclosed sections 
having a common power bus and principally containing motor control 
units.
    Nonmetallic-sheathed cable (Types NM, NMC, and NMS). A factory 
assembly of two or more insulated conductors having an outer sheath of 
moisture resistant, flame-retardant, nonmetallic material.
    Oil (filled) cutout. (Over 600 volts, nominal.) A cutout in which 
all or part of the fuse support and its fuse link or disconnecting 
blade are mounted in oil with complete immersion of the contacts and 
the fusible portion of the conducting element (fuse link), so that arc 
interruption by severing of the fuse link or by opening of the contacts 
will occur under oil.
    Open wiring on insulators. Open wiring on insulators is an exposed 
wiring method using cleats, knobs, tubes, and flexible tubing for the 
protection and support of single insulated conductors run in or on 
buildings, and not concealed by the building structure.
    Outlet. A point on the wiring system at which current is taken to 
supply utilization equipment.
    Outline lighting. An arrangement of incandescent lamps or electric 
discharge lighting to outline or call attention to certain features, 
such as the shape of a building or the decoration of a window.
    Overcurrent. Any current in excess of the rated current of 
equipment or the ampacity of a conductor. It may result from overload, 
short circuit, or ground fault.
    Overhaul means to perform a major replacement, modification, 
repair, or rehabilitation similar to that involved when a new building 
or facility is built, a new wing is added, or an entire floor is 
renovated.
    Overload. Operation of equipment in excess of normal, full-load 
rating, or of a conductor in excess of rated ampacity that, when it 
persists for a sufficient length of time, would cause damage or 
dangerous overheating. A fault, such as a short circuit or ground 
fault, is not an overload. (See Overcurrent.)
    Panelboard. A single panel or group of panel units designed for 
assembly in the form of a single panel; including buses, automatic 
overcurrent devices, and with or without switches for the control of 
light, heat, or power circuits; designed to be placed in a cabinet or 
cutout box placed in or against a wall or partition and accessible only 
from the front. (See Switchboard.)
    Permanently installed decorative fountains and reflection pools. 
Pools that are constructed in the ground, on the ground, or in a 
building in such a manner that the fountain or pool cannot be readily 
disassembled for storage, whether or not served by electrical circuits 
of any nature. These units are primarily constructed for their 
aesthetic value and are not intended for swimming or wading.
    Permanently installed swimming, wading, and therapeutic pools. 
Pools that are constructed in the ground or partially in the ground, 
and all other capable of holding water in a depth greater than 1.07 m 
(42 in.). The definition also applies to all pools installed inside of 
a building, regardless of water depth, whether or not served by 
electric circuits of any nature.
    Portable X-ray. X-ray equipment designed to be hand-carried.
    Power and control tray cable (Type TC). A factory assembly of two 
or more insulated conductors, with or without associated bare or 
covered grounding conductors under a nonmetallic sheath, approved for 
installation in cable trays, in raceways, or where supported by a 
messenger wire.
    Power fuse. (Over 600 volts, nominal.) See Fuse.
    Power-limited tray cable (Type PLTC). A factory assembly of two or 
more insulated conductors under a nonmetallic jacket.
    Power outlet. An enclosed assembly, which may include receptacles, 
circuit breakers, fuseholders, fused switches, buses, and watt-hour 
meter mounting means, that is intended to supply and control power to 
mobile homes, recreational vehicles, or boats or to serve as a means 
for distributing power needed to operate mobile or temporarily 
installed equipment.
    Premises wiring. (Premises wiring system.) The interior and 
exterior wiring, including power, lighting, control, and signal circuit 
wiring together with all of their associated hardware, fittings, and 
wiring devices, both permanently and temporarily installed, that 
extends from the service point of utility conductors or source of power 
(such as a battery, a solar photovoltaic system, or a generator, 
transformer, or converter) to the outlets. Such wiring does not include 
wiring internal to appliances, fixtures, motors, controllers, motor 
control centers, and similar equipment.
    Qualified person. One who has received training in and has 
demonstrated skills and knowledge in the construction and operation of 
electric equipment and installations and the hazards involved.

    Note 1 to the definition of "qualified person:" Whether an 
employee is considered to be a "qualified person" will depend upon 
various circumstances in the workplace. For example, it is possible 
and, in fact, likely for an individual to be considered 
"qualified" with regard to certain equipment in the workplace, but 
"unqualified" as to other equipment. (See 1910.332(b)(3) for 
training requirements that specifically apply to qualified persons.)


    Note 2 to the definition of "qualified person:" An employee 
who is undergoing on-the-job training and who, in the course of such 
training, has demonstrated an ability to perform duties safely at 
his or her level of training and who is under the direct supervision 
of a qualified person is considered to be a qualified person for the 
performance of those duties.

    Raceway. An enclosed channel of metal or nonmetallic materials 
designed expressly for holding wires, cables, or busbars, with 
additional functions as permitted in this standard. Raceways include, 
but are not limited to, rigid metal conduit, rigid nonmetallic conduit, 
intermediate metal conduit, liquidtight flexible conduit, flexible 
metallic tubing, flexible metal conduit, electrical metallic tubing, 
electrical nonmetallic tubing, underfloor raceways, cellular concrete floor 
raceways, cellular metal floor raceways, surface raceways, wireways, 
and busways.
    Readily accessible. Capable of being reached quickly for operation, 
renewal, or inspections, so that those needing ready access do not have 
to climb over or remove obstacles or to resort to portable ladders, 
chairs, etc. (See Accessible.)
    Receptacle. A receptacle is a contact device installed at the 
outlet for the connection of an attachment plug. A single receptacle is 
a single contact device with no other contact device on the same yoke. 
A multiple receptacle is two or more contact devices on the same yoke.
    Receptacle outlet. An outlet where one or more receptacles are 
installed.
    Remote-control circuit. Any electric circuit that controls any 
other circuit through a relay or an equivalent device.
    Sealable equipment. Equipment enclosed in a case or cabinet that is 
provided with a means of sealing or locking so that live parts cannot 
be made accessible without opening the enclosure. The equipment may or 
may not be operable without opening the enclosure.
    Separately derived system. A premises wiring system whose power is 
derived from a battery, a solar photovoltaic system, or from a 
generator, transformer, or converter windings, and that has no direct 
electrical connection, including a solidly connected grounded circuit 
conductor, to supply conductors originating in another system.
    Service. The conductors and equipment for delivering electric 
energy from the serving utility to the wiring system of the premises 
served.
    Service cable. Service conductors made up in the form of a cable.
    Service conductors. The conductors from the service point to the 
service disconnecting means.
    Service drop. The overhead service conductors from the last pole or 
other aerial support to and including the splices, if any, connecting 
to the service-entrance conductors at the building or other structure.
    Service-entrance cable. A single conductor or multiconductor 
assembly provided with or without an overall covering, primarily used 
for services, and is of the following types:
    (1) Type SE. Type SE, having a flame-retardant, moisture resistant 
covering; and
    (2) Type USE. Type USE, identified for underground use, having a 
moisture-resistant covering, but not required to have a flame-retardant 
covering. Cabled, single-conductor, Type USE constructions recognized 
for underground use may have a bare copper conductor cabled with the 
assembly. Type USE single, parallel, or cable conductor assemblies 
recognized for underground use may have a bare copper concentric 
conductor applied. These constructions do not require an outer overall 
covering.
    Service-entrance conductors, overhead system. The service 
conductors between the terminals of the service equipment and a point 
usually outside the building, clear of building walls, where joined by 
tap or splice to the service drop.
    Service entrance conductors, underground system. The service 
conductors between the terminals of the service equipment and the point 
of connection to the service lateral.
    Service equipment. The necessary equipment, usually consisting of 
one or more circuit breakers or switches and fuses, and their 
accessories, connected to the load end of service conductors to a 
building or other structure, or an otherwise designated area, and 
intended to constitute the main control and cutoff of the supply.
    Service point. The point of connection between the facilities of 
the serving utility and the premises wiring.
    Shielded nonmetallic-sheathed cable (Type SNM). A factory assembly 
of two or more insulated conductors in an extruded core of moisture-
resistant, flame-resistant nonmetallic material, covered with an 
overlapping spiral metal tape and wire shield and jacketed with an 
extruded moisture-, flame-, oil-, corrosion-, fungus-, and sunlight-
resistant nonmetallic material.
    Show window. Any window used or designed to be used for the display 
of goods or advertising material, whether it is fully or partly 
enclosed or entirely open at the rear and whether or not it has a 
platform raised higher than the street floor level.
    Signaling circuit. Any electric circuit that energizes signaling 
equipment.
    Storable swimming or wading pool. A pool that is constructed on or 
above the ground and is capable of holding water to a maximum depth of 
1.07 m (42 in.), or a pool with nonmetallic, molded polymeric walls or 
inflatable fabric walls regardless of dimension.
    Switchboard. A large single panel, frame, or assembly of panels on 
which are mounted, on the face or back, or both, switches, overcurrent 
and other protective devices, buses, and (usually) instruments. 
Switchboards are generally accessible from the rear as well as from the 
front and are not intended to be installed in cabinets. (See 
Panelboard.)
    Switch--(1) General-use switch. A switch intended for use in 
general distribution and branch circuits. It is rated in amperes, and 
it is capable of interrupting its rated current at its rated voltage.
    (2) General-use snap switch. A form of general-use switch 
constructed so that it can be installed in device boxes or on box 
covers, or otherwise used in conjunction with wiring systems recognized 
by this subpart.
    (3) Isolating switch. A switch intended for isolating an electric 
circuit from the source of power. It has no interrupting rating, and it 
is intended to be operated only after the circuit has been opened by 
some other means.
    (4) Motor-circuit switch. A switch, rated in horsepower, capable of 
interrupting the maximum operating overload current of a motor of the 
same horsepower rating as the switch at the rated voltage.
    Switching devices. (Over 600 volts, nominal.) Devices designed to 
close and open one or more electric circuits. Included in this category 
are circuit breakers, cutouts, disconnecting (or isolating) switches, 
disconnecting means, interrupter switches, and oil (filled) cutouts.
    Transportable X-ray. X-ray equipment installed in a vehicle or that 
may readily be disassembled for transport in a vehicle.
    Utilization equipment. Equipment that utilizes electric energy for 
electronic, electromechanical, chemical, heating, lighting, or similar 
purposes.
    Ventilated. Provided with a means to permit circulation of air 
sufficient to remove an excess of heat, fumes, or vapors.
    Volatile flammable liquid. A flammable liquid having a flash point 
below 38 [deg]C (100 [deg]F), or a flammable liquid whose temperature 
is above its flash point, or a Class II combustible liquid having a 
vapor pressure not exceeding 276 kPa (40 psia) at 38 [deg]C (100 
[deg]F) and whose temperature is above its flash point.
    Voltage (of a circuit). The greatest root-mean-square (rms) 
(effective) difference of potential between any two conductors of the 
circuit concerned.
    Voltage, nominal. A nominal value assigned to a circuit or system 
for the purpose of conveniently designating its voltage class (as 120/
240 volts, 480Y/277 volts, 600 volts). The actual voltage at which a 
circuit operates can vary from the nominal within a range that permits 
satisfactory operation of equipment.
    Voltage to ground. For grounded circuits, the voltage between the 
given conductor and that point or conductor of the circuit that is 
grounded; for ungrounded circuits, the greatest voltage between the 
given conductor and any other conductor of the circuit.
    Watertight. So constructed that moisture will not enter the 
enclosure.
    Weatherproof. So constructed or protected that exposure to the 
weather will not interfere with successful operation. Rainproof, 
raintight, or watertight equipment can fulfill the requirements for 
weatherproof where varying weather conditions other than wetness, such 
as snow, ice, dust, or temperature extremes, are not a factor.
    Wireways. Sheet-metal troughs with hinged or removable covers for 
housing and protecting electric wires and cable and in which conductors 
are laid in place after the wireway has been installed as a complete 
system.

0
8. Appendix A to Subpart S is revised to read as follows:

Appendix A--References for Further Information

    The references contained in this appendix provide nonmandatory 
information that can be helpful in understanding and complying with 
Subpart S of this Part. However, compliance with these standards is 
not a substitute for compliance with Subpart S of this Part.
    ANSI/API RP 500-1998 (2002) Recommended Practice for 
Classification of Locations for Electrical Installations at 
Petroleum Facilities Classified as Class I Division 1 and Division 
2.
    ANSI/API RP 505-1997 (2002) Recommended Practice for 
Classification of Locations for Electrical Installations at 
Petroleum Facilities Classified as Class I, Zone 0, Zone 1 and Zone 
2.
    ANSI/ASME A17.1-2004 Safety Code for Elevators and Escalators.
    ANSI/ASME B30.2-2005 Overhead and Gantry Cranes (Top Running 
Bridge, Single or Multiple Girder, Top Running Trolley Hoist).
    ANSI/ASME B30.3-2004 Construction Tower Cranes.
    ANSI/ASME B30.4-2003 Portal, Tower, and Pedestal Cranes.
    ANSI/ASME B30.5-2004 Mobile And Locomotive Cranes.
    ANSI/ASME B30.6-2003 Derricks.
    ANSI/ASME B30.7-2001 Base Mounted Drum Hoists.
    ANSI/ASME B30.8-2004 Floating Cranes And Floating Derricks.
    ANSI/ASME B30.11-2004 Monorails And Underhung Cranes.
    ANSI/ASME B30.12-2001 Handling Loads Suspended from Rotorcraft.
    ANSI/ASME B30.13-2003 Storage/Retrieval (S/R) Machines and 
Associated Equipment.
    ANSI/ASME B30.16-2003 Overhead Hoists (Underhung).
    ANSI/ASME B30.22-2005 Articulating Boom Cranes.
    ANSI/ASSE Z244.1-2003 Control of Hazardous Energy Lockout/Tagout 
and Alternative Methods.
    ANSI/ASSE Z490.1-2001 Criteria for Accepted Practices in Safety, 
Health, and Environmental Training.
    ANSI/IEEE C2-2002 National Electrical Safety Code.
    ANSI K61.1-1999 Safety Requirements for the Storage and Handling 
of Anhydrous Ammonia.
    ANSI/UL 913-2003 Intrinsically Safe Apparatus and Associated 
Apparatus for Use in Class I, II, and III, Division 1, Hazardous 
(Classified) Locations.
    ASTM D3176-1989 (2002) Standard Practice for Ultimate Analysis 
of Coal and Coke.
    ASTM D3180-1989 (2002) Standard Practice for Calculating Coal 
and Coke Analyses from As-Determined to Different Bases.
    NFPA 20-2003 Standard for the Installation of Stationary Pumps 
for Fire Protection.
    NFPA 30-2003 Flammable and Combustible Liquids Code.
    NFPA 32-2004 Standard for Drycleaning Plants.
    NFPA 33-2003 Standard for Spray Application Using Flammable or 
Combustible Materials.
    NFPA 34-2003 Standard for Dipping and Coating Processes Using 
Flammable or Combustible Liquids.
    NFPA 35-2005 Standard for the Manufacture of Organic Coatings.
    NFPA 36-2004 Standard for Solvent Extraction Plants.
    NFPA 40-2001 Standard for the Storage and Handling of Cellulose 
Nitrate Film.
    NFPA 58-2004 Liquefied Petroleum Gas Code.
    NFPA 59-2004 Utility LP-Gas Plant Code.
    NFPA 70-2002 National Electrical Code. (See also NFPA 70-2005.)
    NFPA 70E-2000 Standard for Electrical Safety Requirements for 
Employee Workplaces. (See also NFPA 70E-2004.)
    NFPA 77-2000 Recommended Practice on Static Electricity.
    NFPA 80-1999 Standard for Fire Doors and Fire Windows.
    NFPA 88A-2002 Standard for Parking Structures.
    NFPA 91-2004 Standard for Exhaust Systems for Air Conveying of 
Vapors, Gases, Mists, and Noncombustible Particulate Solids.
    NFPA 101-2006 Life Safety Code.
    NFPA 496-2003 Standard for Purged and Pressurized Enclosures for 
Electrical Equipment.
    NFPA 497-2004 Recommended Practice for the Classification of 
Flammable Liquids, Gases, or Vapors and of Hazardous (Classified) 
Locations for Electrical Installations in Chemical Process Areas.
    NFPA 505-2006 Fire Safety Standard for Powered Industrial Trucks 
Including Type Designations, Areas of Use, Conversions, Maintenance, 
and Operation.
    NFPA 820-2003 Standard for Fire Protection in Wastewater 
Treatment and Collection Facilities.
    NMAB 353-1-1979 Matrix of Combustion-Relevant Properties and 
Classification of Gases, Vapors, and Selected Solids.
    NMAB 353-2-1979 Test Equipment for Use in Determining 
Classifications of Combustible Dusts.
    NMAB 353-3-1980 Classification of Combustible Dust in Accordance 
with the National Electrical Code.

Appendices B and C [Removed]

0
9. Appendices B and C to Subpart S are removed.

[FR Doc. E7-1360 Filed 2-9-07; 8:45 am]

BILLING CODE 4510-26-P

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