Figure 2-3. Minimum clearances in front of electrical equipment (600 V or less)

DOE-HDBK-1092-98

working space shall be 3 ft, 3 1/2 ft, or 4 ft, depending upon existing conditions. The conditions are

as follows:

Condition 1: These are exposed live components on one side of a space and ungrounded parts on the

other side.

Condition 2: The electrical equipment is mounted or set on one wall, and the wall on the opposite

side is grounded. If the qualified worker should accidentally contact the conductive wall while

touching live components, a circuit would be completed to ground and a fatal shock might occur.

Condition 3: The electrical equipment is mounted or set on one wall, and additional electrical

equipment is mounted or set on the opposite side of the room. There are live components on both sides

of the room. The qualified worker might accidentally make contact with live components and be in

series with a hot phase and the grounded metal of the electrical equipment, which could produce a

fatal shock.

See Figure 2-3 for the clearance requirements in front of electrical equipment rated 600 V or less.

See NEC Section 110-16(a) Exception 1 for clearance requirements in the rear of electrical

equipment.

Electrical

equipment

opposite

No live or

electrical

Grounded

grounded

equipment

parts

Electrical

equipment

Min.

dist.

Condition 2

Condition 3

Condition 1

Volts to ground Min. dist. Volts to ground Min. dist. Volts to ground Min. dist.

0 - 150 V

3 ft.

0 - 150 V 3 ft.

0 - 150 V

3 ft.

151 - 600 V

3 ft.

151 - 600 V 3 1/2 ft. 151 - 600 V

4 ft.

L93 0350

NEC Table 110-16 (a)

OSHA Table S-1

Figure 2-3. Minimum clearances in front of electrical equipment (600 V or less).

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