The GFR-2 is factory calibrated to operate with the model of sensor identified on the nameplate. When the ground fault occurs, the Sensor creates a signal that will trip the GFR-2 relay. DPDT output contacts are provided to operate the breaker shunt trip coil, contactor or the annunciator. After the fault has been cleared, the GFR-2 will reset automatically (non-latching option) or, with the mechanically latching option, has to be manually reset. The electrically latched version of the relay requires that the power supply be shut off to reset the relay. The time-delay option has a definite time/current characteristic.