18.24—Electrical clearances.

Minimum clearances between uninsulated electrical conductor surfaces, or between uninsulated conductor surfaces and grounded metal surfaces, within the enclosure shall be as follows:

Minimum Clearances Between Uninsulated Surfaces

Phase-to-Phase Voltage (rms)	Clearances (inches)
Phase-to-Phase Voltage (rms)	Phase-to-Phase	Phase-to-Ground or Control Circuit
0 to 250	0.25	0.25
251 to 600	0.28	0.25
601 to 1000	0.61	0.25
1001 to 2400	1.4	0.6
2401 to 4160	3.0	1.4

Code of Federal Regulations

[57 FR 61209, Dec. 23, 1992]

CFR

18.24—Electrical clearances.

Code of Federal Regulations