Siemens 3RV1821-1ED10 Molded Case Circuit Breaker

Siemens 3RV1821-1ED10 Molded Case Circuit Breaker, size S0, is a transformer-protection device from the 3RV family designed for compact, reliable overcurrent protection in control panels and low‑voltage distribution systems. This molded-case breaker uses screw terminals for secure wiring and carries UL 489 and CSA C22.2 No. 5-02 approvals, ensuring compliance with common North American safety standards. It features an a-trigger at 4 A and an n-trigger at 82 A to coordinate precisely with transformer protection schemes and enable selective tripping under fault conditions, backed by a thermal‑magnetic trip mechanism for both overloads and short circuits. Built for space‑conscious installations, the 3RV1821-1ED10 delivers dependable transformer protection in industrial environments without compromising ease of assembly or wiring integrity, making it a purpose‑built solution where transformer safety and panel footprint are critical.