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

Open Table
Phase-to-Phase Voltage (rms) Clearances (inches)
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

[57 FR 61209, Dec. 23, 1992]


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