Arc flash protection relay D0920 series

ACDIN rail

The D0920 Arc Detection Unit is a high-speed arc-detection device for electrical power-distribution systems. The D0920 supports up to three point sensors (A0220) mounted in a switchboard, and requires a 230 Vac supply. On the occurrence of an arc fault, the D0920 detects the fault and pulses the trip output in less than 1 ms. The fast trip time reduces the risk of personal injury and equipment damage. The D0920 is typically supplied from the switchboard main power. The AC voltage may fail when an arc fault develops. The D0920 uses energy stored in an internal capacitor to trip the circuit breaker. The storage capacitor is an extremely long-life electrolytic capacitor with a specified life time of more than 30 years at an ambient temperature of 50°C (121°F). The trip energy stored is sufficient for circuit breakers with a 220/250 Vdc shunt trip coil. The D0920 has one output indication relay with an isolated normally-open contact, and one output indication relay with an isolated normally-closed contact. Additional features include power and trip indication, test mode, and sensitivity adjustment.