Sensitive DC Ground Fault Relays for Coal Mines.
Yenchek-MR; Trutt-FC; Kohler-JL; Et Al
Proc 8th WVU Min Electrotech Conf Morgantown West Virginia, 7/30-8/1/86 PP 40-45 :40-45
This paper describes research aimed at virtually eliminating electrocutions on DC utilization circuits and has resulted in an effective circuit protective device, called a sensitive ground fault relay. This relay can detect and act to interrupt small deadly ground currents that can trigger ventricular fibrillation in humans, while ignoring spurious power system signals. Initial relay performance criteria were established to ensure reliability for mine duty as well as effectiveness for shock prevention. Mineworthy prototypes consisting of a saturable transformer current sensor and an electronic relay were constructed and complied with the performance standards in laboratory tests.
Proc. 8th WVU Min. Electrotech. Conf., Morgantown, West Virginia, 7/30-8/1/86, PP. 40-45