Siemens 3RV1021-1AA10 Molded Case Circuit Breaker

Siemens 3RV1021-1AA10 is a size S0 motor-protection molded‑case circuit breaker (MPCB) designed for DIN‑rail mounting in control panels, and it belongs to the SIRIUS family of protection devices. It provides thermal‑magnetic motor protection with a Class 10 A‑release setting of 1.1–1.6 A and a 21 A short‑circuit release, using screw terminals and a 220–690 VAC rating to suit small to medium motors. In practical terms, it can protect motors up to about 0.55 kW in typical 220–690 VAC applications; Siemens notes this model is no longer available and the recommended successor is 3RV2011-1AA10, making it appropriate to consider the newer device for updated availability and compatibility in legacy panel designs.