400 A MCCB with serious interrupting capacity
The Siemens SENTRON 3VA2440-7MS32-0AB0 is a 3-pole molded case circuit breaker rated for 400 A continuous at 40 °C, with an adjustable thermal-magnetic trip unit covering 1200 A to 6000 A. This is a starter-protection design — the trip curve is shaped for motor inrush, so it holds on starting current but clears a locked-rotor fault fast. The interrupting rating hits 330 kA at 240 V AC, 242 kA at 415/440 V, and still manages 187 kA at 500 V. At 690 V it drops to 9 kA, which is typical for this class — you're into current-limiting fuse territory above 500 V.
What the ratings mean for your panel
The 400 A rating holds across the full ambient range from 40 °C to 70 °C — no derating headache in a hot enclosure. The adjustable trip band (1200-6000 A) lets you dial in the magnetic pickup to match the motor's locked-rotor current without swapping the breaker. The 330 kA SCCR at 240 V means this breaker can sit on a transformer secondary with unlimited fault current and still clear a bolted fault without exploding. At 415 V, the 242 kA rating is enough for most industrial service-entrance positions. The 2 HP auxiliary switches built into the frame give you status feedback for the PLC or alarm panel without adding external relays.
Panel fit and integration
The breaker measures 248 mm high, 138 mm wide, and 110 mm deep — a standard 3-pole MCCB footprint that fits most distribution panelboards and motor control center buckets. Mounting is via the rear panel or DIN rail adapter (not included). The 3-pole design with no undervoltage release and no communication module keeps wiring simple: line in, load out, auxiliary contacts for status. Operating temperature range is -25 °C to 70 °C, storage from -40 °C to 80 °C.