Accessory variant: Undervoltage release
Range: Sentron
Operating voltage: 24 V dc

Auxiliary contact and undervoltage release for 3VA from Siemens. The auxiliary and alarm switches for 3VA circuit breakers with encapsulated housing can be installed in all sizes of circuit breakers up to 630 A. All auxiliary and alarm switches are designed as changeover contacts, providing high flexibility for planning and installation. Auxiliary switches indicate the position of the main contacts of the encapsulated circuit breakers. Release alarm switches signal any tripping of a protective circuit breaker, regardless of the cause of the trip. Electrical alarm switches are activated as soon as the main contacts of the encapsulated circuit breaker open when the disconnect switch is triggered by the ETU. Short-circuit alarm switches signal trips only when they are initiated by a short circuit. Undervoltage releases trip the encapsulated circuit breaker if the nominal voltage fails or drops to 70-35% of the normal value (in accordance with the relevant standard). The units are available with rated voltages in the following range: 230 V ac and 24 V dc. Shunt releases of type STL can be installed in the left accessory compartment as an alternative to an undervoltage release. The units are available with five rated voltages in the following range: 230 V ac and 24 V ac/dc.