MCCB for line protection — 50 A frame, 220 kA interrupting at 240 V
The Siemens SENTRON 3VA1150-6EF32-0JH0 is a 3-pole molded case circuit breaker (MCCB) designed for line protection — meaning it sits at the incoming feeder or main distribution point, not downstream on a motor branch. Its interrupting rating of 220 kA at 240 V is the headline number: that's the maximum fault current it can safely clear without welding contacts or rupturing the case. At 415 V it still holds 154 kA, and at 690 V it drops to 17 kA — the arc energy scales with voltage, so the same breaker has less headroom on higher-voltage systems. Rated 50 A continuous at 40 °C ambient, and it holds that 50 A all the way to 50 °C — no derating needed in a warm panel. Above that it steps down: 49 A at 55 °C, 48 A at 60 °C, 46 A at 65 °C, 45 A at 70 °C. The insulation voltage is rated 800 V, so this breaker is comfortable on 480/277 V or 600 V systems within its interrupting envelope. The auxiliary switch complement is 2 auxiliary switches plus 1 trip alarm switch (HQ configuration), and it ships with a shunt trip (STL) release already fitted — that's the '6EF32' in the order code. The shunt trip lets a remote signal (from a safety relay, PLC, or E-stop circuit) open the breaker without a person at the panel. Maximum power loss is 14.6 W, which matters for thermal coordination inside a sealed enclosure.
Panel fit — dimensions and mounting
Measures 76.2 mm wide, 130 mm tall, 70 mm deep. Same footprint as the 3VA1110 frame.