Regulations last checked for updates: May 16, 2024

Title 30 - Mineral Resources last revised: May 09, 2024
§ 18.24 -

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 2500.250.25
251 to 6000.280.25
601 to 10000.610.25
1001 to 24001.40.6
2401 to 41603.01.4
[57 FR 61209, Dec. 23, 1992]
authority: 30 U.S.C. 957,961
source: 33 FR 4660, Mar. 19, 1968, unless otherwise noted.
cite as: 30 CFR 18.24