400 A MCCB with shunt trip — what the ratings mean for your panel
The Siemens SENTRON 3VA2340-6HN32-0JC0 is a 3-pole molded case circuit breaker rated for 400 A continuous current, designed for line protection in distribution panels. Its interrupting capacity reaches 242 kA at 240 V and 187 kA at 415/440 V, dropping to 121 kA at 500 V and 7.5 kA at 690 V — so it handles high-fault utility feeds at low voltage but you need to check the available fault current at your service voltage before committing the BOM line. The breaker carries its full 400 A rating up to 50 °C ambient; above that it derates linearly to 340 A at 70 °C. If the panel sits in a hot enclosure or near other heat sources, that derating curve governs the real ampacity — not the nameplate 400 A. This variant ships with an integrated shunt trip release (STL) and two auxiliary switches (HQ), so it can be tripped remotely by a safety circuit or PLC output and report its status back without adding external accessories. The shunt trip is wired separately from the main power path — verify coil voltage compatibility with your control voltage before wiring. Maximum power loss is 96 W, which matters for enclosure thermal calculations when grouping multiple breakers in a single panel.
Mounting and footprint
Dimensions are 248 mm high, 138 mm wide, 110 mm deep — a standard SENTRON 3VA frame size for 400 A. Mounts on a DIN rail or directly to a backplate via the screw-mount lugs. The 138 mm width means it occupies three 45 mm pole spaces, typical for a 3-pole MCCB in a distribution board.