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Electric Power >> Energized vs. Deenergized Work >> Live Line/Bare Hand Work and Tools

Energized vs. Deenergized Work
Live Line/Bare Hand Work and Tools

Live Line/Bare Hand Work (LLBHW)All line work procedures emphasize preventing potentially hazardous voltage differences across a worker's body. Such prevention usually involves avoiding contact between the worker and energized parts through the use of engineering controls, administrative controls (including deenergizing), and electrical protective equipment (for example, PPE, IPE).

Live Line/Bare Hand Work (LLBHW) is different—269-qualified employees [See 1910.269(x)] are in direct contact with energized conductors and must maintain minimum approach distances from the tower and all other grounded surfaces and other lines and circuits. (See 1910.269(q)(3).) This work is frequently performed from an electrically insulated aerial lift (for example, a bucket truck), which has its platform insulated from the ground or earth. (See 1910.269(q)(3)(iii).) The workers on the platform electrically bond, or connect, the platform to the power line and are literally charged to the same voltage as the line. (See 1910.269(q)(3)(vi).) This is the "bird on the wire" concept like birds landing on overhead power lines safely. In addition, PPE for LLBHW consists of conductive rather than insulating materials. Workers performing LLBHW wear conductive hooded coveralls and gloves and are bonded to the conductor. When aerial lifts are not used, workers performing LLBHW typically access the energized conductor using insulated ladders or platforms, which insulate the workers from the tower.
1910.269 Photo credit: Oak Ridge National Laboratory See:
1910.269(j) - Live Line Tools

1910.269(j)(2) - Care, testing, and cleaning of live line tools

1910.269(l)(2)(i), (l)(3), (l)(7) - PPE for live line work

1910.269(q) - Operations near energized lines or equipment

Also see: 1910.137 - Electrical protective devices
 


Training and Job Briefings
Workers performing or supervising the LLBHW must be thoroughly trained in LLBHW procedures and techniques before being assigned to this work. Training and job briefings must include information about line voltage, minimum approach distances, and the voltage limitations of any conductive equipment to be used. (See 1910.269(c) and 1910.269(q)(3)(i) and (ii))

Live Line/Bare Hand Tools, Devices, and Weather
For LLBHW, the "269" standard requires that:
  • All insulating equipment, insulating tools, platforms, and aerial devices used in LLBHW must be designed, tested, and intended for LLBHW. These items must be kept clean and dry during use.
     
  • Automatic reclosing devices on lines being worked on must be set to non-reclosing.
     
  • No LLBHW can be done during bad weather that includes thunderstorms, high winds [See 1910.269(q)(3)(v)], snowstorms, and ice storms. Aerial devices
     
  • Only non-conductive hand lines can be used between workers bonded to the energized conductor and personnel on the ground, and no uninsulated items can be passed from a worker on a structure to workers performing LLBHW.
     
  • Insulated ladders and platforms used in LLBHW must be properly secured, not overloaded, used only for LLBHW, and be capable of supporting 2.5 times the intended load.
     
  • When aerial lifts are used for LLBHW, the equipment must be designed for this type of work. The aerial lift must also have both upper and lower controls in which the lower controls can override the upper controls to bring the unit down in an emergency. The controls must be checked for proper operation prior to work.
     
  • Prior to use, trucks must be grounded or barricaded and treated as energized.
     
  • The boom must be tested by raising and placing the bucket in contact with the energized conductor for at least three minutes. The leakage current must be measured and cannot exceed 1 microampere for each 1KV of conductor voltage. Work from an aerial lift must be suspended if a malfunction is indicated.
     
  • Workers must be connected to conductive bucket liners that are bonded to the energized conductor for the duration of the work.
     
  • A non-conductive plate showing minimum approach distances must be installed on the boom in clear view of the bucket operator, and a non-conductive measuring device must be available for checking the distances. Minimum approach distances must be maintained between the bucket and all grounded objects.
The above requirements can be found in 1910.269(h)(2) and (3), (j)(2), and (q).

Job Briefings and Best Practices
Energized vs. Deenergized Work
Minimum Approach Distances
Equipotential Zone
Overhead Line Work
Use of Aerial Lifts
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