The under voltage release(UVR) as the part of remote tripping is used for EasyPact EZC100 circuit breakers. This UVR is worked at 200~277VAC voltage(Un),50/60Hz. Tripping threshold is between 0.35 and 0.7times the related voltage. This release trips the circuit breaker when control voltage rises drops below a tripping threshold. Circuit breaker closing is possible only if the voltage exceeds 0.85 times the related voltage. This installation of SHT is external mounting.