30 CFR 77.800 : Mineral Resources (§ 1.1 To Parts 1291-1299) — (§ 1.1 To Parts 105-199) — Mine Safety And Health Administration, Department Of Labor (§ 1.1 To Parts 105-199) — Coal Mine Safety And Health (§ 70.1 To § 90.301) — Mandatory Safety Standards, Surface Coal Mines And Surface Work Areas Of Underground Coal Mines (§ 77.1 To Subpart U) — Surface High-Voltage Distribution (§ 77.800 To § 77.811) — High-voltage circuits; circuit breakers.

High-voltage circuits supplying power to portable or mobile equipment shall be protected by suitable circuit breakers of adequate interrupting capacity which are properly tested and maintained and equipped with devices to provide protection against under voltage, grounded phase, short circuit and overcurrent. High-voltage circuits supplying power to stationary equipment shall be protected against overloads by either a circuit breaker or fuses of the correct type and capacity.