OSHA requirements are set by statute, standards and regulations. Our interpretation letters explain these requirements and how they apply to particular circumstances, but they cannot create additional employer obligations. This letter constitutes OSHA's interpretation of the requirements discussed. Note that our enforcement guidance may be affected by changes to OSHA rules. Also, from time to time we update our guidance in response to new information. To keep apprised of such developments, you can consult OSHA's website at https://www.osha.gov.

August 23, 1996

Mr. Stephen C. Yohay
McDermott, Will & Emery
1850 K Street, N.W.
Washington, DC 20006-2296

Dear Mr. Yohay:

This is in response to your letter of June 14 requesting an interpretation of the electrical power generation, transmission and distribution (electric power generation) standard, 29 CFR 1910.269. Your Question and our reply follow.

Question: Is the removal and replacement of a transformer a kind of "operation" which may be performed by one qualified employee, without the presence of a second employee?

Reply: An employer may use one qualified employee to perform work such as the installation, removal or repair of equipment, such as a transformer, if that employee is not exposed to contact, directly or indirectly, with parts energized at more than 600 volts for "operations" covered under paragraph 1910.269(l)(1)(ii). Additionally, the employer must comply with other applicable provisions, including paragraph 1910.269(p)(4)(ii), of the electric power generation standard.

The Agency cannot determine that the work performed by the qualified employee in your fact pattern meets the requirements of paragraph 1910.269(l)(1)(ii)(B) because three of your assumptions are invalid. Your fourth assumption that "[t]he bucket would be suspended from an insulated truck boom" are questioned in light of your sixth assumption that "[t]here would be a non-insulated jib and winch attached to the bucket." As noted in my March 6 letter to the Illinois Power Company (Mr. Michael D. Crandell), the aerial lift would not be considered "insulated" anytime the uninsulated jib or winch approaches closer to a utility pole (or any other grounded surface) than the minimum approach distances specified in Table R-6. When a line workers uses a winch which is connected (by fiber rope) to the transformer mounted on a utility pole, the insulation on the aerial lift would be bridged and therefore would not provide any protection to the employee. Also, your ninth assumption claims that the note following paragraph 1910.269(l)(2)(iii) indicates that the line would be considered as guarded after installation of "insulated line covers."

This note refers to permanent guards provided for substation and electric generating station installations. It does not refer to the temporary installation of electrical protective equipment on overhead power lines. If your ninth assumption refers to the use of insulating plastic guard equipment as shown in the Illinois Power Company videotape discussed in our aforementioned March 6 letter, portions of the overhead conductors still would be exposed to contact.

We appreciate your interest in employee safety and health. If we can be of further assistance, please contact Mr. Ronald J. Davies in the Office of Safety and Compliance Assistance, telephone (202) 219-8031, extension 110.


John B. Miles, Jr., Director
Directorate of Compliance Programs