What this 400 A MCCB delivers
The Siemens 3VA2340-5KP32-0BC0 is a SENTRON molded case circuit breaker rated for 400 A continuous at 40 °C, with the ETU850 electronic trip unit handling line protection across a 3-pole configuration. Breaking capacity hits 187 kA at 240 V, 121 kA at 415 V, and 75.6 kA at 500 V — enough headroom for high-fault utility feeds or transformer secondaries where SCCR coordination matters. The ETU850 release supports communication functions, meaning this breaker can talk to a BMS or PLC for remote trip indication and load monitoring — not just a dumb overcurrent device.
Full 400 A holds from 40 °C through 50 °C, then steps down: 375 A at 55 °C, 350 A at 60 °C, 325 A at 65 °C, and 300 A at 70 °C. The storage limit governs shipping and idle spares, not running conditions.
Physical fit and auxiliary wiring
Verify the mounting footprint against your existing busbar or cable lug layout before ordering. Comes with 2 HQ auxiliary switches and an undervoltage release (UVR) integrated. The UVR design means the breaker trips on loss of control voltage — common for emergency-stop chains or undervoltage protection schemes. If those are required, look at the 3VA2 with GF or the ETU860 option.