BBC Ground Fault Relay Systems provide safe, sensitive protection against ground faults on grounded electrical distribution systems. The system consists of a special design current transformer which is called a ground sensor, and a solid state ground relay. The ground sensor encircles all 3 phase conductors and neutral if present, and provides an output signal to the trip device on the circuit breaker. the ground relay may also be used to initiate an alarm on high resistance grounded systems where a trip is not desired. In some applications the sensor can be mounted on the neutral to ground connection.