What the ratings mean for fit
The Siemens SENTRON 3VA2440-6HN32-0HL0 is a 3-pole molded case circuit breaker rated for 400 A continuously at ambient temperatures from 40 °C through 70 °C without derating — the full 400 A holds across that entire thermal band, so you don't need to oversize for a warm panel. Its interrupting capacity reaches 242 kA at 240 V AC, 187 kA at 415 V and 440 V, 121 kA at 500 V, and 9 kA at 690 V, meaning it can safely clear fault currents at those levels without upstream cascading. The unit is designed for line protection (cable/feeder protection), not motor or generator duty, and carries no ground-fault monitoring. A shunt trip (STL) is built in for remote tripping, and the auxiliary switch configuration includes two auxiliary switches plus one trip alarm and one electrical alarm switch.
Integration and panel fit
The breaker measures 248 mm high, 138 mm wide, and 110 mm deep — a standard footprint for a 400 A frame in the SENTRON 3VA family. It mounts directly into a switchboard or distribution panel via the rear studs; no DIN-rail adapter is used at this frame size. The 3-pole design occupies a single unit width. Maximum power loss is 63.5 W, which should be factored into the enclosure thermal budget. Storage range is -40 °C to 80 °C; operating ambient is -25 °C to 70 °C.