The Siemens 3VA1150-3EF36-0KC0 is a SENTRON molded case circuit breaker (MCCB) rated for 50 A continuous current at 40 °C, with a TM240 thermal-magnetic overcurrent release and a shunt trip (STL) auxiliary release. It is a 3-pole unit configured for line protection — meaning it sits upstream of a load, not on a motor branch circuit with integrated overloads. The 75.6 kA breaking capacity at 240 V tells you it can interrupt a fault up to that level without cascading upstream, which is the number that governs panel SCCR coordination.
Ratings and what they mean for fit
The 50 A rating holds 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. If your panel ambient runs above 50 °C, the breaker still carries 45 A at 70 °C — that's the figure to use for continuous-load sizing, not the 50 A nameplate. Breaking capacity steps down with system voltage: 75.6 kA at 240 V, 52.5 kA at 415 V, 32 kA at 440 V, and 10.5 kA at 690 V. For a 480 V panel, the 32 kA at 440 V is the closest published point — expect a similar figure at 480 V, but the 415 V rating (52.5 kA) is the one to use for IEC 60947-2 coordination studies on a 400 V line. Rated insulation voltage is 800 V, so it is electrically rated for 690 V systems with margin. The front face carries IP40 protection — fine for a closed panel, not for washdown exposure.
Panel fit and integration
The 3VA1150-3EF36-0KC0 measures 76.2 mm wide, 130 mm tall, and 70 mm deep — a standard 3-pole MCCB footprint that mounts on a DIN rail or panel plate. It ships with 2 auxiliary switches (HQ type) and a shunt trip (STL) pre-installed, so you do not need to order those as separate add-on kits for remote trip or status feedback.