New Construction or Dismantling of Facilities

DOE-HDBK-1092-2004

7.5.2.2 NEW CONSTRUCTION OR DISMANTLING OF FACILITIES

If isolating devices are not in place and energization is impossible from any source, single-

phase grounding is appropriate, acceptable, and safe. If energization is possible by the closure

of a jumper or isolating device, shorts and grounds shall be used unless conductor handling

activity makes this impractical or impossible because of line design or construction process.

7.5.2.3 MINIMUM APPROACH DISTANCE FROM UNGROUNDED CONDUCTORS

The minimum approach distances in Section 2.13.4.1 shall be maintained from ungrounded

conductors at the work location. The ground may be omitted if the making of the ground is

impractical or the resulting conditions are more hazardous than working on the lines or

equipment without grounding. However, all work shall be done as if the line or equipment were

energized.

7.5.2.4 VISIBLE THREE-PHASE SHORT AND GROUND REQUIRED

Visible three-phase short circuiting may be accomplished through conductive parts such as guy

wires and unpainted metal tower members, but shall not be effected through a grounding mat or

other concealed conductors.

7.5.2.5 GROUND CIRCUIT

No power disconnect switch, power circuit breaker, transformer, wave trap, or fuse shall be part

of the protective grounding circuit.

Table 7-2. AC live-line work minimum approach distance.

Distance, Phase to Employee

Phase to Phase

Phase to Ground Exposure Phase to Phase Exposure

Nominal Voltage (kV)

(ft - in)

1 or less

Avoid contact

1.1 to 15

2-1

2-2

15.1 to 36

2-4

2-7

36.1 to 46

2-7

2-10

46.1 to 72.5

3-0

3-6

72.6 to 121

3-2

4-3

138 to 145

3-7

4-11

161 to 169

4-0

5-8

230 to 242

5-3

7-6

345 to 362

8-6

12-6

500 to 550

11-3

18-1

765 to 800

14-11

26-0

Note 1: These distances take into consideration the highest switching surge an employee will be exposed

to on any system with air as the insulating medium and the maximum voltage shown.

Note 2: The clear live line tool distances shall equal or exceed the values for the indicated voltage ranges.

Note 3: See 29 CFR 1910.269, Appendix B for information on how the minimum approach distances were

derived.

7-10