A. All metallic sheaths, armors, and conduits enclosing power conductors shall be electrically continuous throughout and shall be grounded effectively.

B. Metallic frames, casing, and other enclosures of stationary electric equipment that can become “alive” through failure of insulation or by contact with energized parts shall be grounded effectively or equivalent protection shall be provided.

C. When electric equipment is operated from three-phase alternating current circuits originating in transformers connected to provide a neutral point, a continuous grounding conductor of adequate size shall be installed and connected to the neutral point and to the frames of the power-utilizing equipment. Such grounding conductors shall be grounded at the neutral point and at intervals along the conductor if feasible. A suitable circuit breaker or switching device shall be provided having a ground-trip coil connected in series with the grounding conductor to provide effective ground-fault tripping.

History

1966, c. 594, § 45.1-79; 1994, c. 28.