Undervoltage release function: protection of the load in the event of a voltage drop, positive safety (device switches when voltage is interrupted), can be used for emergency stop circuits with break contact. Suitable for circuit breakers S200, residual current circuit breakers F200 A up to 100 A, F200 B up to 63 A and residual current circuit breakers DS201/DS202C /DS203NC (with SN201-IH coupling module/auxiliary switch for DS203NC) and residual current circuit breaker combinations DS200 (DDA200 + S200) as well as SD200 load disconnectors.