SENTRON 3VA1163-4EF32-0JC0 — 63 A MCCB with TM240 release and shunt trip
The Siemens 3VA1163-4EF32-0JC0 is a 3-pole SENTRON molded case circuit breaker rated for continuous current of 63 A at ambient temperatures up to 50 °C, with a TM240 thermal-magnetic overcurrent release and an integrated shunt trip (STL) for remote tripping. It carries a breaking capacity of 121 kA at 240 V, 75.6 kA at 415 V, and 52.5 kA at 440 V — figures that give the panel designer real headroom for high-fault installations like a mill's main feeder or a large motor control center.
The 121 kA at 240 V and 75.6 kA at 415 V are the ultimate short-circuit breaking capacities (Icu) — the maximum fault current the breaker can safely interrupt once. For selectivity coordination downstream, the real number to watch is the 52.5 kA at 440 V and the 11.9 kA at 690 V, because those are the levels where the upstream breaker must hold off while the downstream device clears. In a typical 480 V distribution panel, the 75.6 kA at 415 V (roughly equivalent at 480 V) means this breaker can sit at the main or a large subfeed without worrying about fault energy exceeding its capability, as long as the available fault current stays under that ceiling. The TM240 release gives a thermal pickup range up to 240 A frame rating, but the breaker's continuous rating is set at 63 A by the installed trip unit — so it's a 63 A breaker in a 240 A frame, which gives mechanical robustness and spare capacity for the magnetic short-circuit pickup.
Above that, it steps down: 60.48 A at 55 °C, 59.22 A at 60 °C, 57.96 A at 65 °C, and 56.7 A at 70 °C. If the breaker lives in a crowded enclosure or near heat-generating gear, the 55 °C to 65 °C derating band is where you lose 2.5 to 5 A — enough to matter on a fully loaded feeder.