30 C.F.R. § 18.24 Electrical clearances.
Title 30 - Mineral Resources
Minimum clearances between uninsulated electrical conductor surfaces, or between uninsulated conductor surfaces and grounded metal surfaces, within the enclosure shall be as follows: [57 FR 61209, Dec. 23, 1992]
Title 30: Mineral Resources
PART 18—ELECTRIC MOTOR-DRIVEN MINE EQUIPMENT AND ACCESSORIES
Subpart B—Construction and Design Requirements
§ 18.24 Electrical clearances.
Minimum Clearances Between Uninsulated Surfaces------------------------------------------------------------------------ Clearances (inches) ----------------------- Phase-to- Phase-to-Phase Voltage (rms) Phase-to- Ground or Phase Control Circuit------------------------------------------------------------------------0 to 250........................................ 0.25 0.25251 to 600...................................... 0.28 0.25601 to 1000..................................... 0.61 0.251001 to 2400.................................... 1.4 0.62401 to 4160.................................... 3.0 1.4------------------------------------------------------------------------
