Siemens 3RV1021-4AA15 Molded Case Circuit Breaker

Siemens 3RV1021-4AA15 is a S0‑size molded‑case circuit breaker from the SIRIUS family, designed for motor protection in industrial control panels. It provides a continuous current rating of 16 A, a mechanical life of about 100,000 switching cycles, and an auxiliary contact arrangement of 1 NO + 1 NC. The device includes screw terminals and a short‑circuit release rated at 208 A, with standard switching capacity that accommodates a transverse auxiliary switch. It offers IP20 front protection, and a surge‑voltage withstand of up to 6,000 V, making it suitable for machine control where transient high voltages may be encountered. The unit is specified for operation up to 2,000 m above sea level. Siemens notes this model as a legacy product no longer available, with the recommended successor in the current lineup being 3RV2021-4AA15. This makes it a compact motor‑protection option for compact panels, where a dedicated motor protector with integrated auxiliary contacts and screw‑terminal connections is appropriate.