Figure 2-4. Minimum clearances in front of electrical equipment (over 600 V)

DOE-HDBK-1092-98

2.9.2 ELECTRICAL EQUIPMENT RATED OVER 600 VOLTS

NEC Section 110-34(a) and Table 110-34(a) list the minimum clearance required for working spaces

in front of high-voltage electrical equipment such as switchboards, control panels, switches, circuit

breakers, switchgear, motor controllers, etc.

There are three conditions to apply as in NEC Section 110-16(a) and Table 110-16(a)

1. Where there are exposed live components on one side of a space and no live or ungrounded

parts on the other side.

2. Where there are exposed live components on one side and grounded parts on the other such

as concrete, brick, and tile walls that are considered to be grounded parts.

3. Where there are exposed live components on both sides.

See Figure 2-4 for the clearance requirements in front of electrical equipment rated at over 600 V.

See NEC Section 110-34(a) Exception for clearance requirements in the rear of electrical equipment.

Electrical

equipment

opposite

electrical

No live or

Grounded

equipment

grounded

parts

Electrical

equipment

Min.

dist.

Condition 1

Condition 2

Condition 3

Volts to ground

Min. dist.

Volts to ground

Min. dist.

Volts to ground

Min. dist.

601 - 2,500 V

3 ft.

601 - 2,500 V

4 ft.

601 - 2,500 V

5 ft.

2,501 - 9,000 V

4 ft.

2,501 - 9,000 V

5 ft. 2,501 - 9,000 V

6 ft.

9,001 - 25,000 V

5 ft.

9,001 - 25,000 V

6 ft. 9,001 - 25,000 V

9 ft.

25,001 - 75,000 V

6 ft.

25,001 - 75,000 V

8 ft. 25,001 - 75,000 V 10 ft.

above 75,000 V

8 ft.

above 75,000 V 10 ft. above 75,000 V 12 ft.

L93 0349

NEC Table 110-34

OSHA Table S-2

Figure 2-4. Minimum clearances in front of electrical equipment (over 600 V).

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