GroundRules
30 CFR 77.902: Low- and medium-voltage ground check monitor circuits.
Where this section sits in the code
- Title 30—Mineral Resources
- CHAPTER I—MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR
- SUBCHAPTER O—COAL MINE SAFETY AND HEALTH
- PART 77—MANDATORY SAFETY STANDARDS, SURFACE COAL MINES AND SURFACE WORK AREAS OF UNDERGROUND COAL MINES
- Subpart J—Low- and Medium-Voltage Alternating Current Circuits
On and after September 30, 1971, three-phase low- and medium-voltage resistance grounded systems to portable and mobile equipment shall include a fail safe ground check circuit or other no less effective device approved by the Secretary to monitor continuously the grounding circuit to assure continuity. The fail safe ground check circuit shall cause the circuit breaker to open when either the ground or pilot check wire is broken. Cable couplers shall be constructed to cause the ground check continuity conductor to break first and the ground conductor last when being uncoupled when pilot check circuits are used.
Collected 2026-08-27T02:25:24Z. Source file · JSON