Siemens 3RV1742-5DD10 Motor Circuit Breaker

Siemens 3RV1742-5DD10 is a three-pole motor-protective circuit breaker (size S3) designed to protect motors and control circuits in industrial panels from overloads and short circuits. It is UL 489-listed and CSA C22.2 No. 5-02 approved, making it suitable for use in North American electrical installations. The device combines thermal and magnetic tripping with an A‑trigger rated at 25 A and an instantaneous N‑trigger rating of 325 A to respond to inrush and fault conditions common with motor operation. Wiring uses screw-terminal connections for secure field installation, and the breaker is configured for standard switching capacity as a plant-protection device. In Siemens’ Sirius portfolio, this model sits in the legacy 3RV family with a documented path forward into the 3RV2 line; Siemens lists 3RV2742-5DD10 as the preferred successor for future projects. Typical applications include protection of three-phase motors in pumps, fans, conveyors, and other automation equipment, where coordinated protection with motor starters and overload relays is required. The compact S3 frame enables mounting in standard control panels, while the integrated thermal-magnetic protection provides selective tripping to minimize downtime and equipment damage during electrical faults.