400 A fixed rating, no derating curve to worry about
The Siemens 3VA2440-6HN32-0HA0 is a SENTRON molded case circuit breaker with a fixed 4800 A rating — that's not a range, it's one number, so the trip curve is locked to that frame. Rated 400 A continuous at 40 °C, and it holds that same 400 A all the way up to 70 °C ambient. That means no derating math when the panel runs hot; the breaker delivers its full ampacity in a warm enclosure. Interrupting capacity is 242 kA at 240 V, dropping to 187 kA at 415 V and 440 V, then 121 kA at 500 V, and 9 kA at 690 V. That's a high-fault breaker — sized for a main or tie position where the available fault current is substantial. The 3-pole construction and line-protection design make it a straightforward fit for a feeder or incoming section. This variant includes a shunt trip release (STL) for remote tripping — useful in an emergency-stop chain or a downstream coordination scheme. No auxiliary switch, no ground-fault monitoring, no communication module. It's a bare functional breaker with the shunt trip as the only accessory release.
Panel fit and footprint
Dimensions are 248 mm high by 138 mm wide by 110 mm deep. That's a standard SENTRON 3VA frame size for this amp class — it bolts into a panel on the same mounting pattern as other 400 A 3VA breakers. No surprise on the drill template if you're swapping one in. Power loss is 63.5 W maximum at rated load. That's the heat you need to vent in the enclosure — not trivial, but within what a standard ventilated panel handles for a main breaker of this size.