The Siemens SENTRON 3VA1150-3EF32-0HA0 is a 3-pole molded case circuit breaker rated for 50 A continuous current (Iu) and built for line protection duty. It carries a TM240 thermal-magnetic overcurrent release and a shunt trip (STL) auxiliary release — no undervoltage release, no auxiliary contacts, no communication module. The interrupting ratings climb to 75.6 kA at 240 V and 52.5 kA at 415 V, so it handles high-fault utility feeds or transformer secondaries without cascading upstream. At 440 V it still breaks 32 kA; at 690 V it holds 10.5 kA. That spread tells you this breaker is sized for 480 V panelboards where the available fault current is substantial — common in industrial distribution.
Thermal derating and panel fit
The 50 A rating holds flat from 40 °C through 50 °C ambient — no derating needed in a ventilated enclosure. At 55 °C it drops to 48 A, at 60 °C to 47 A, at 65 °C to 46 A, and at 70 °C to 45 A. If your panel runs hot near the top of a gland plate, factor that 45 A floor. The front face carries IP40 protection — fine for a clean indoor panel; not rated for washdown. Dimensions are 70 mm deep, 76.2 mm wide, 130 mm tall — standard 3-pole MCCB footprint for DIN-rail or screw-mount backpan. No auxiliary contact slot populated, so if you need a status feedback contact, you'll add one externally or order a variant with the aux pre-installed.