Fault current protection device

TLDR: In this paper, a fault-current protection device, in which a first subordinate device, which acts as a faultcurrent circuit-breaker, for protecting against fault currents of a first type, is combined with a second sub-device, which act as a residual-current circuit breaker, is designed to react to fault currents from direct current, alternating current and pulsating fault currents.

Abstract: Fault current protection device, in which a first subordinate device, which acts as a fault-current circuit-breaker, for protecting against fault currents of a first type, is combined with a second subordinate device, which acts as a residual-current circuit-breaker, for protecting against fault currents of a second type. According to the invention, it is provided that the first subordinate device (1), fault-current circuit-breaker, is designed in such a way that it reacts at least to a.c. fault currents, and that the second subordinate device (2), residual-current circuit-breaker, is designed to react to fault currents from direct current, alternating current and pulsating fault currents, and that the sensitivity of its triggering is matched to the earth-leakage circuit-breaker in such a way that the triggering in the case of a.c. fault current and in the case of pulsating fault currents lies essentially above that of the fault-current circuit-breaker, and the triggering in the case of fault currents from smooth direct current corresponds to the sensitivity of the fault-current circuit-breaker in the case of a.c. fault current or in the case of pulsating fault currents.