What this MCCB carries — and what that means for your feeder
The Siemens SENTRON 3VA2340-5JP32-0DA0 is a 3-pole molded case circuit breaker rated for 400 A continuous at 40 °C — that's your feeder or main disconnect for a 400 A bus, not a branch device. At 240 V it interrupts 187 kA; at 415 V it still holds 121 kA, so it handles high-fault utility feeds without cascading upstream. The 400 A rating holds flat through 50 °C; above that it derates stepwise to 300 A at 70 °C, which matters if you're stuffing it into a hot corner of a panel.
Built-in undervoltage release and comms — one less add-on module
This variant ships with an undervoltage release (UVR) integrated — that's the entry — so if you're designing a safety circuit that drops the breaker on voltage loss, you don't need a separate shunt trip or UVR accessory. It also carries a communication function onboard, which on the 3VA platform typically means it can talk to a higher-level controller or energy-management system. The auxiliary switch design is listed as "without", so if you need a remote status contact, plan on adding an auxiliary switch block. Power loss at full load is 98.5 W maximum — that's the heat you have to vent from the enclosure; factor it into your thermal budget.
Footprint and panel fit
Dimensions are 110 mm deep, 138 mm wide, 248 mm tall. That's a standard 3-pole MCCB footprint for the 400 A frame size — it'll drop into a SENTRON mounting base or DIN-rail adapter without surprises. The width is the key constraint for multi-breaker panels: at 138 mm, three across eat 414 mm of backpanel width before you account for phase barriers.