The Siemens SIRIUS 3RV1912-1CN6 is an undervoltage release with a leading auxiliary switch, designed for 200 V control circuits. It's the accessory that drops the main contactor or circuit breaker when control voltage falls below the dropout threshold — essential for preventing automatic restart after a brownout or power dip on a motor branch. Rated for 200 V, this release mounts onto SIRIUS S00 frame breakers and contactors. The leading auxiliary switch changes state ahead of the main contacts, giving the PLC a clean 'voltage lost' signal before the motor drops off — useful for sequencing a controlled stop or latching an E-stop circuit. Front touch protection meets IP20 per IEC 60529, finger-safe for vertical contact. That means a panel builder can reach into the enclosure without worrying about incidental contact with the release terminals, as long as the approach is from the front.
Panel Integration
The release occupies the accessory slot on the left side of the breaker or contactor — no extra DIN space required. Terminals accept 2x (0.5 to 1.5 mm²) solid or 2x (0.75 to 2.5 mm²) finely stranded with ferrule. Screw torque 0.8 to 1.2 N·m, Pozidriv size 2 tip.