What this 400 A MCCB carries
The Siemens SENTRON 3VA2440-5HN32-0HC0 is a 3-pole molded case circuit breaker rated for 400 A continuous at 40 °C through 70 °C — no derating needed across that band, which simplifies panel sizing in warm cabinets. Its interrupting capacity hits 187 kA at 240 V, 121 kA at 415/440 V, 75.6 kA at 500 V, and 9 kA at 690 V, so it handles high-fault service-entrance or distribution positions without cascading upstream. The 110 mm depth and 138 mm width fit standard MCCB mounting footprints; the 248 mm height leaves room for the integrated shunt trip (STL) and two HQ auxiliary switches.
Selectivity and coordination headroom
Rated 4 800 A minimum and maximum — that's the fixed short-time pickup, not a range. For a 400 A frame, that gives you a solid 12x overload band before the breaker starts its intentional delay, which helps with motor inrush or transformer magnetizing currents. The 63.5 W maximum power loss at full load matters for enclosure thermal rise calculations; in a sealed panel, that's roughly 215 BTU/hr you need to vent.
Panel integration notes
Mounts on a standard DIN rail or direct panel-mount via the 138 mm × 248 mm footprint. The shunt trip (STL) and two HQ auxiliary switches are factory-installed — no field retrofit of the trip unit. Operating temperature range -25 °C to 70 °C; storage from -40 °C to 80 °C. Designed for line protection (not motor protection), so it's a distribution breaker, not a motor circuit protector.