Siemens 3RV1021-4CA10 Motor Protection Circuit Breaker

Siemens 3RV1021-4CA10 is a 3-pole Sirius motor protection circuit breaker (MPCB) sized S0, engineered to protect industrial motors on 3‑phase networks up to 690 VAC. It combines thermal overload protection with a magnetic short‑circuit trip, featuring a Class 10 A‑rel release that is adjustable from 17 to 22 A (no auxiliary switch) and screw-terminal connections for straightforward wiring. With a short‑circuit release rating of 286 A and a stated short‑circuit current rating up to 50 kA at 400 V, it provides robust protection for motors and is rated IP20 on the front with 6,000 V impulse withstand. This device is designed to install in motor circuits where direct motor protection is required, typically used alongside contactors in pumps, fans, conveyors, and compressors to limit motor damage from overloads and short circuits while allowing manual isolation when needed.