SEL arc-flash detection technology significantly decreases the time it takes a relay to trip in response to an arc fault, which reduces hazardous arc‑flash incident energy. SEL combines light-sensing technology with fast overcurrent protection to provide high-speed arc-flash detection (AFD).
Arc Sense technology (AST) from SEL is an innovative solution that detects high-impedance faults (HIF) on a distribution system. A high-impedance fault occurs when a conductor contacts a ground surface but does not produce a large fault current. SEL’s patented AST detects and clears faults that might not be detected by conventional overcurrent elements. AST algorithms provide improved fault detection over traditional methods as well as enhanced security when compared to existing technologies.
The SEL-751 Feeder Protection Relay is ideal for directional overcurrent, fault location, arc-flash detection, and high-impedance fault detection applications. Flexible I/O options, easy mounting, and fast settings make the SEL-751 the right solution for industrial and utility feeder protection.
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.