Trailing Cables

DOE-HDBK-1092-2004

5.10.4 TRAILING CABLES

Trailing cables used in electrical systems of mines shall meet requirements expressed in 30

CFR 57.12038, 30 CFR 75 Subpart G, and 30 CFR 77, Subpart G.

Each trailing cable of portable and mobile equipment shall have short-circuit and ground-fault

protection for each ungrounded conductor. Protective devices shall safely interrupt all

ungrounded conductors under fault conditions. Requirements for over current protection of each

ungrounded conductor shall be those expressed in 30 CFR 57.12003, 30 CFR 75 Subpart G,

and 30 CFR 77, Subpart G.

Trailing cables shall be attached to equipment so that strain on electrical connections does not

occur and damage to cable jacket and internal conductor insulation is prevented. Portable

distribution boxes can be used and shall meet the requirements in 30 CFR 57.12006 and

57.12007. Trailing cables and power conductors shall be protected against physical damage

from mobile equipment by using bridges, trenches, or suspension from the mine roof.

Disconnecting devices for trailing cables shall be equipped with means for attaching a padlock

for LO/TO purposes per 30 CFR 57.12016, 57.12017, 75.511, and 77.501.

5.10.5 TROLLEY CIRCUITS FOR TRACK HAULAGE

Trolley wires and exposed trolley-feeder wires shall be installed and maintained in accordance

to the requirements in 30 CFR 57.12050, 57.12086, and 30 CFR 75, Subpart K.

Trolley wires and trolley-feeder wires shall be protected against over current in accordance to

the requirements of 30 CFR 57.12001 and 75.1001.

Track serving as the trolley circuit return shall be bonded or welded according to the

requirements of 30 CFR 57.12042 and 75, Subpart K. Energized trolley wires and exposed

trolley-feeder wires shall be guarded in places where accidental contact with them is possible.

This includes areas where supplies are stored, loaded, or unloaded.

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