What it is and what it does
The Siemens SENTRON 3VM1150-3EE36-0AA2 is a 3-pole molded case circuit breaker (MCCB) with a TM220 thermal-magnetic overcurrent release, designed for line protection in distribution panels. It carries a continuous current rating of 50 A at 40 °C and a maximum frame rating of 500 A, with interrupting capacities of 76 kA at 240 V AC, 53 kA at 415 V AC, 32 kA at 440 V AC, and 12 kA at 500 V AC. The 50 A rating holds flat through 50 °C — no derating needed in a warm panel — then steps down to 49 A at 55 °C, 48 A at 60 °C, 46 A at 65 °C, and 45 A at 70 °C. That thermal curve means a panel builder can size the branch at a full 50 A without over-speccing for typical enclosure ambient temperatures.
Physical fit and panel integration
The breaker measures 76.2 mm wide, 130 mm tall, and 70 mm deep — a standard 3-pole MCCB footprint that fits most DIN-rail or panel-mount enclosures without re-drilling. The front face carries an IP40 protection rating, meaning it is protected against tools and small wires entering the enclosure but not sealed against moisture; keep it inside a rated cabinet. Rated insulation voltage is 800 V, so the breaker is suitable for 480/277 V and 600 V systems with margin. Maximum power dissipation is 15 W at full load — account for that heat in the enclosure thermal budget when grouping multiple breakers.