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 shunt trip (STL) and two HQ auxiliary switches are factory-installed — no field retrofit of the trip unit. Designed for line protection (not motor protection), so it's a distribution breaker, not a motor circuit protector.