What this MCCB carries — and what that means for your panel
The Siemens SENTRON 3VA2340-5HL32-0DC0 is a 3-pole molded case circuit breaker rated 400 A continuous at 40 °C, with a maximum interrupting capacity of 187 kA at 240 V. That 187 kA figure is the short-circuit current rating (SCCR) at the line terminals — it tells you this breaker can safely clear a fault up to that level without welding contacts or venting plasma into the enclosure. At 415 V and 440 V the SCCR holds at 121 kA; at 690 V it drops to 7.5 kA, so for 690 V applications verify the available fault current stays under that threshold. The continuous current rating is flat at 400 A from 40 °C through 50 °C, then derates linearly to 340 A at 70 °C. That thermal curve is the one that governs real-world panel loading — if your enclosure ambient runs at 60 °C, plan for 370 A, not 400 A. The breaker also carries an undervoltage release (UVR) and two HQ auxiliary switches, so it can trip on loss of control voltage and report its status back to a PLC or annunciator without an add-on module.
Panel fit and integration
The breaker measures 248 mm high by 138 mm wide by 110 mm deep — a standard footprint for a 400 A frame in the SENTRON 3VA platform. It mounts via four screws to a backplate or DIN-rail adapter (not included); the 138 mm width leaves room for side-by-side mounting in a multi-breaker lineup, though thermal derating should be recalculated when breakers are ganged without spacing. Maximum power loss is 98.5 W at rated load — that heat must be vented or accounted for in the enclosure's thermal budget. The operating temperature range is -25 °C to 70 °C, storage from -40 °C to 80 °C, so it handles both cold warehouses and warm panel interiors without issue.