The Siemens SIRIUS 3RV1952-1AD0 is an undervoltage release designed for the 3RV13 5 series of motor-protective circuit breakers. It trips the breaker when the control voltage drops below its dropout threshold, preventing an automatic restart when power returns — a standard safety interlock for machinery where unexpected re-energisation could create a hazard. Rated for 110...127 V AC and 110...125 V DC, this release covers the common 110 V control-voltage range found across European and North American industrial panels. The dual AC/DC rating simplifies stocking — one part number handles both supply types within those bands.
Panel integration
This release mounts directly onto the 3RV13 5 circuit breaker — no separate DIN-rail footprint or additional wiring space needed. The connection is mechanical and electrical via the breaker's accessory slot, so panel layout stays unchanged when adding undervoltage protection to an existing motor starter.