A new concept in ground check/ground fault monitoring

A novel combined multifrequency ground check monitor/ground fault relay was recently designed and has received Mine Safety and Health Administration acceptance. This ground check monitor is available in three different frequencies and is intended for application on circuits where the ground circuits cannot be isolated by arc traps alone. The multifrequency system can also be used for control applications by sending signals of different frequencies over the same power cable. The 5/7.5 amp trip ground fault portion of the combined unit uses a very accurate and stable electronic circuit with state-of-the-art components to process fault currents sensed by the associated current transformer