Ground-fault protection and the problem of nuisance tripping of critical feeders

National Electrical Code (NEC) ground-fault protection (GFP) requirements are examined in light of the various risk factors. The risk factors related to arcing ground faults and the possibility of nuisance tripping on critical feeders are examined. The adequacy of state-of-the-art ground-fault protection equipment is also examined. Special attention is given to process industries and health care facilities. It is concluded that those responsible for designing and installing GFP systems need to apply them more effectively and that manufacturers and code writers need to look at alternatives to present GFP schemes