SEL-4520 Arc-Flash Test Module
The SEL-4520 Arc-Flash Test Module provides a convenient way to test the operation of arc-flash detection relays installed in metal-clad and metal-enclosed switchgear. The SEL-4520 is used to test the SEL-751 and SEL-751A Feeder Protection Relays and other arc-flash detection relays that use light and overcurrent to sense an arc-flash event.
To test an arc-flash detection (AFD) system, the SEL-4520 simultaneously applies current to an SEL-751 or SEL-751A while triggering an LED light or optional camera flash (not included). The duration of the light pulse is controlled through DIP switches, and the triggering of the light is controlled by a demodulated IRIG-B input (light triggers at top of second) or through a pushbutton (TST/RST). Current circulates through the SEL-4520 and the external test source (not included) until the TST/RST pushbutton is pressed. Once TST/RST is pressed, the light is applied, and current then circulates through the relay and the test source, simulating an arc-flash condition.