400 A MCCB for high-fault panels
The Siemens SENTRON 3VA2340-6HN32-0AC0 is a 3-pole molded case circuit breaker (MCCB) rated for 400 A continuous at 40 °C, designed for line protection in main distribution panels. Its interrupting capacity hits 242 kA at 240 V AC and still holds 187 kA at 415/440 V, dropping to 121 kA at 500 V and 7.5 kA at 690 V — that SCCR headroom means it handles high-fault utility feeds without cascading upstream. Rated current holds flat at 400 A through 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 — say, a packed enclosure with multiple high-current breakers — that derating curve is the real limit, not the 400 A nameplate. The breaker ships with two auxiliary switches (HQ type) fitted, and the supplied basic switch is order code 3VA2340-6HN32-0AA0. No undervoltage release, no ground-fault monitoring, no communication function — this is a straight line-protection MCCB for hardwired distribution.
Panel fit and thermal management
Dimensions are 248 mm high × 138 mm wide × 110 mm deep. That 138 mm width on a 3-pole frame is standard for SENTRON 3VA2 breakers — it bolts into the same bus-bar grid as other 400 A frames in the series. Maximum power loss is 96 W at rated load, so factor that into your enclosure ventilation if the panel is sealed. Operating temperature range is -25 °C to 70 °C; storage from -40 °C to 80 °C. The storage limit governs handling and warehousing, not running conditions.