What it is and what it does
The Siemens SENTRON 3VA2340-7HL32-0AC0 is a 3-pole molded case circuit breaker (MCCB) rated for 400 A continuous current, designed for line protection in distribution panels. It breaks faults up to 330 kA at 240 V, 242 kA at 415 V and 440 V, 187 kA at 500 V, and 7.5 kA at 690 V — so at the common 400 V class it clears a 242 kA fault without cascading upstream.
Thermal derating and real-world fit
The 400 A rating holds up to 50 °C ambient; above that it derates to 385 A at 55 °C, 370 A at 60 °C, 355 A at 65 °C, and 340 A at 70 °C. If your panel runs hot, the actual continuous current you can pull is lower — size your load accordingly. Maximum power loss is 96 W, which matters for enclosure heat budgeting.
Panel integration and switching configuration
The breaker measures 138 mm wide, 248 mm tall, and 110 mm deep — standard for a 400 A frame in the SENTRON 3VA line. It ships with two auxiliary switches (HQ type) installed, but no undervoltage release, no ground-fault monitoring, and no communication module. If you need those, you're looking at a different variant or an add-on kit. Operating temperature range is -25 °C to 70 °C; storage range is -40 °C to 80 °C.