Line protection MCCB with 187 kA interrupting capacity
The Siemens SENTRON 3VA1150-5EF32-0JC0 is a 3-pole molded case circuit breaker rated for 50 A continuous current with a TM240 thermal-magnetic release, sized for line protection in distribution panels. Its interrupting capacity hits 187 kA at 240 V and 121 kA at 415 V — figures that tell you it can clear a bolted fault on a large transformer secondary without the arc flashing over to adjacent buswork. At 690 V it still holds 17 kA, so it handles industrial 690 V drives and motor control centers where the available fault current is lower but the voltage stress on the arc chute is higher. The TM240 release is a fixed thermal-magnetic type — no interchangeable rating plugs, no electronic adjustment. That means the 50 A continuous rating is baked in; if the load grows past 50 A, swap the breaker, not the trip unit. The thermal curve tracks the 50 A mark flat from 40 °C through 50 °C, then derates to 48 A at 55 °C, 47 A at 60 °C, 46 A at 65 °C, and 45 A at 70 °C. In a sealed panel with poor airflow, that derating is the number that governs, not the nameplate 50 A. The auxiliary contact block ships as 2 HQ (high-quality) switches — these are rated for electronic loads, not just pilot-duty relay coils. The shunt trip (STL) release is built in, so a remote trip signal from an E-stop or fire-alarm relay lands on the breaker without an external contactor. No undervoltage release, no ground-fault module, no communication function — this is a straight line-protection breaker with a remote-trip option and auxiliary status feedback.
Panel fit and wiring constraints
The breaker measures 76.2 mm wide, 130 mm tall, and 70 mm deep. The width is a standard 3-pole MCCB footprint. Front IP40 means the face is protected against tools and wires. The integrated auxiliary trip is order code 3VA9688-0BL32 — the factory-fitted shunt trip coil. The auxiliary switches are form-C contacts rated for electronic loads.