45.1-161.188 - Grounding. - Virginia Statutes

§ 45.1-161.188. Grounding.

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

B. Metallic frames, casing, and other enclosures of stationary electricequipment that can become "alive" through failure of insulation or bycontact with energized parts shall be grounded effectively, or equivalentprotection shall be provided.

C. Three-phase alternating current circuits used underground shall containeither a direct or derived neutral which shall be grounded through a suitableresistor at the power center, and a grounding circuit, originating at thegrounded side of the grounding resistor, shall extend with the powerconductors and serve as the grounding conductor for the frames of all theelectrical equipment supplied power from that circuit. High-voltage circuitsextending underground shall be supplied with a grounding resistor of a properOhmic value located on the surface to limit the voltage drop in the groundingcircuit external to the resistor to not more than 100 volts under faultconditions. The grounding resistor shall be rated for maximum fault currentcontinuously and insulated from ground for a voltage equal to thephase-to-phase voltage of the system. All resistance-grounded alternatingcircuits used underground shall include a fail-safe ground check circuit tomonitor continuously the grounding circuit to assure the continuity of theground conductor.

(1966, c. 594, § 45.1-79; 1994, c. 28; 1999, c. 256.)