29 CFR 1926.956 - Underground lines.
(a) General. Paragraph (b) of this section applies to electric equipment connected by cord and plug. Paragraph (c) of this section applies to portable and vehicle-mounted generators used to supply cord- and plug-connected equipment. Paragraph (d) of this section applies to hydraulic and pneumatic tools.
(b) Cord- and plug-connected equipment. Cord- and plug-connected equipment not covered by subpart K of this part shall comply with one of the following instead of § 1926.302(a)(1):
(1) The equipment shall be equipped with a cord containing an equipment grounding conductor connected to the equipment frame and to a means for grounding the other end of the conductor (however, this option may not be used where the introduction of the ground into the work environment increases the hazard to an employee); or
(2) The equipment shall be of the double-insulated type conforming to subpart K of this part; or
(3) The equipment shall be connected to the power supply through an isolating transformer with an ungrounded secondary of not more than 50 volts.
(c) Portable and vehicle-mounted generators. Portable and vehicle-mounted generators used to supply cord- and plug-connected equipment covered by paragraph (b) of this section shall meet the following requirements:
(1) Equipment to be supplied. The generator may only supply equipment located on the generator or the vehicle and cord- and plug-connected equipment through receptacles mounted on the generator or the vehicle.
(2) Equipment grounding. The non-current-carrying metal parts of equipment and the equipment grounding conductor terminals of the receptacles shall be bonded to the generator frame.
(3) Bonding the frame. For vehicle-mounted generators, the frame of the generator shall be bonded to the vehicle frame.
(4) Bonding the neutral conductor. Any neutral conductor shall be bonded to the generator frame.
(d) Hydraulic and pneumatic tools -
(1) Hydraulic fluid in insulating tools. Paragraph (d)(1) of § 1926.302 does not apply to hydraulic fluid used in insulating sections of hydraulic tools.
(2) Operating pressure. Safe operating pressures for hydraulic and pneumatic tools, hoses, valves, pipes, filters, and fittings may not be exceeded.
If any hazardous defects are present, no operating pressure is safe, and the hydraulic or pneumatic equipment involved may not be used. In the absence of defects, the maximum rated operating pressure is the maximum safe pressure.
(3) Work near energized parts. A hydraulic or pneumatic tool used where it may contact exposed energized parts shall be designed and maintained for such use.
(4) Protection against vacuum formation. The hydraulic system supplying a hydraulic tool used where it may contact exposed live parts shall provide protection against loss of insulating value, for the voltage involved, due to the formation of a partial vacuum in the hydraulic line.
Use of hydraulic lines that do not have check valves and that have a separation of more than 10.7 meters (35 feet) between the oil reservoir and the upper end of the hydraulic system promotes the formation of a partial vacuum.
(5) Protection against the accumulation of moisture. A pneumatic tool used on energized electric lines or equipment, or used where it may contact exposed live parts, shall provide protection against the accumulation of moisture in the air supply.
(6) Breaking connections. Pressure shall be released before connections are broken, unless quick-acting, self-closing connectors are used.
(7) Leaks. Employers must ensure that employees do not use any part of their bodies to locate, or attempt to stop, a hydraulic leak.
(8) Hoses. Hoses may not be kinked.
Title 29 published on 2015-07-01
The following are ALL rules, proposed rules, and notices (chronologically) published in the Federal Register relating to 29 CFR Part 1926 after this date.