Work on Electrical Equipment and Circuits

DOE-HDBK-1092-2004

Once construction of the underground facilities is completed, all wiring used for construction

activities shall be removed and permanent wiring installed in accordance with 29 CFR 1910,

Subpart S, and the NEC as applicable. When the work is not covered by these codes as

referenced, the applicable paragraphs of 30 CFR 57, 75, and 77 shall prevail.

Electrical equipment and conductors must be used in a manner that prevents shocks and burns

to people. Should electrical equipment and conductors present a hazard to people because of

improper installation, maintenance, misuse, or damage, the equipment and conductors must be

tagged out or locked out as a hazard until fixed. All electrical equipment and conductors shall be

chosen and situated in environments conducive to their design and intended use or as tested by

an NRTL for the purpose intended.

The voltage of bare conductors, other than trolley conductors, that are accessible to contact by

people shall not exceed 50 V. Electrical equipment and conductors, other than trailing cables,

shall be protected against overloads and short circuits by fuses or automatic interrupting

devices used in accordance with 29 CFR 1910.304.

Adequate clearance between equipment and bare overhead conductors must be maintained in

accordance with 29 CFR 1910.303. Conductors not being used to supply power to electrical

equipment shall be deenergized and removed from their power supply or have their power

supply locked out and tagged out in accordance with 29 CFR 1910.147 and 29 CFR 1910.333.

All exposed ends shall be insulated.

Access doors and cover plates shall be closed at all times, except for installation, testing, and

repair. Visible signs warning of danger shall be posted at all substations, switch centers, and

control centers to warn people against entry unless they have been authorized to enter and

perform duties in these locations.

5.10.1 WORK ON ELECTRICAL EQUIPMENT AND CIRCUITS

Before any work is performed on electrical equipment or circuits, the power source or sources

shall be deenergized unless power is a required part of the work procedure. Lockout procedures

in 29 CFR 1910.147 and 29 CFR 1910.333 shall be followed. In addition, the following rules

apply for energized work:

1. Power-cable plugs and receptacles for circuits greater than 150 V potential to ground shall

not be connected or disconnected under load unless they are of the load-break type.

Energized power cables in excess of 150 V potential to ground shall be handled in

accordance with 29 CFR 1910.331. Care shall be taken to prevent damage or shock and

burn from the energized cable.

2. Proper tools shall be used to remove or install fuses to protect people from shock or burns.

3. All safety-related electrical work practices covered by the provisions in 29 CFR 1910.331

through .335 shall be followed.

4. Exposed electric connections or resistor grids not protected by location shall be insulated

unless impractical. In this case, guarding shall be installed to prevent accidental contact by

people or equipment.

5-30