Grounding for Emergency and Standby Power Systems

The basic functions of system and equipment grounding is presented, fundamental grounding requirements for service-supplied and separately derived power systems which operate at 600 V or less are discussed. Several grounding arrangements for alternate power supplies are also discussed and graphically illustrated. The grounding requirements are primarily derived from the National Electrical Code, NFPA No. 70-1978. The paper is intended to be the basis for a new chapter on grounding in the next edition of IEEE Standard 446-1974, Recommended Practice for Emergency and Standby Power Systems.