system is used to protect electrical distribution equipment against
damage caused by low magnitude ground currents. GFR-3 operates effectively
on both high and low resistance grounded distribution systems.
sensor, in the event of ground fault, sends a signal to trip the
GFR-3 relay. DPDT output contacts are provided to operate breakers,
annunciators or other devices. The GFR-3 is an enhanced version
of the GFR-2. In addition to the basic ground fault protection mechanism,
there is also a built in self-test circuit and adjustable Time delay.
The self-test is activated by a TEST push-button, which will trigger
the Ground Fault Relay and the breaker. There is also a NO-TRIP
push-button, different from the TEST button, designed specifically
to test the Ground Fault Relay without tripping the breaker.