Code of Federal Regulations (Last Updated: November 8, 2024) |
Title 30 - Mineral Resources |
Chapter I - Mine Safety and Health Administration, Department of Labor |
SubChapter B - Testing, Evaluation, and Approval of Mining Products |
Part 18 - Electric Motor-Driven Mine Equipment and Accessories |
Subpart B - Construction and Design Requirements |
§ 18.24 - Electrical clearances.
Latest version.
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§ 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 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]