BD, NRCD Residual current circuit breaker without over current protection conforms to the standards of GB16916.1, IEC1008, and BS4293 etc. it is used in the circuits of AC 50~60HZ, single phase 230V (220V), three phase 400V (380V) in industrial & mining enterprises, commercial buildings and housing for protection of personal electric shock hazard and electric equipment and for unfrequented switchover of circuits under normal conditions.