SENSITIVE GROUND-FAULT RELAYING.

Interest has been generated in recent years about sensitive ground-fault relaying on the utilization portions of industrial power systems. Sensitive ground-fault protection refers to the concept of detecting low levels of ground-fault current that might cause an electrocution in any human that could be part of the ground-current path. The importance and requirements for sensitive ground-fault protection are reviewed. Relaying schemes for both ac and dc systems are also presented. Although emphasis is on mine power systems, the material is applicable to any portable low-voltage portion of industrial power systems that involve personnel handling.