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
| 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]