The Siemens SENTRON 3VA1440-6MH32-0AA0 is a 3-pole molded case circuit breaker rated for 400 A continuous current at 40 °C to 50 °C ambient, with a TM120M thermal-magnetic overcurrent release. Its interrupting capacity hits 220 kA at 240 VAC, 154 kA at 415 V and 440 V, 121 kA at 500 V, and 17 kA at 690 V — so it handles high-fault utility feeds and transformer secondaries without cascading upstream. Designed as a starter protector, it's a fit for motor branch circuits where you need coordinated short-circuit and overload protection in one package. If your spec calls for those, you add external accessories or choose a different variant. The absence of a trip indicator means you'll need a panel meter or status lamp to confirm the breaker state remotely.
Thermal derating — what the numbers mean
At 55 °C it's 392 A, at 60 °C it's 384 A, at 65 °C it's 376 A, and at 70 °C it's 367 A (–). Max power loss is 76.8 W — that heat has to leave the panel, so don't bury it in a sealed box without ventilation.
Panel fit
The 3-pole footprint is compact for a 400 A MCCB; check your gland plate and busbar spacing before committing the cutout. No communication function means no auxiliary wiring for remote monitoring unless you add an external accessory.