Protective switching device especially difference current (DI) protective circuit-breaker

摘要

A safety switching device includes a summation current transformer (6) for monitoring a network of conductors (Ln) and which drives a tripping element (4) coupled to a latching or breaker mechanism (16) for actuating a power switch (18). A release circuit (5) has a transformer (20) controlled on the secondary side and connected on the primary side with a control (drive) circuit (13) of the tripping element (4). The release circuit specifically generates a control signal (Ss) for the control (drive) circuit (13) of the tripping element (4) during secondary-side short-circuit of the transformer (20).