400 A MCCB with ETU850 — what the ratings mean for your panel
The Siemens SENTRON 3VA2340-6KP32-0DL0 is a 3-pole molded case circuit breaker rated for 400 A continuous current, carrying a 242 kA breaking capacity at 240 V and 187 kA at 415 V — numbers that tell you it handles high-fault utility feeds without cascading upstream. The ETU850 electronic trip unit gives you adjustable long-time, short-time, and instantaneous protection curves, plus ground-fault alarm capability (though not full ground-fault interruption on this variant). Rated insulation voltage is 800 V, so it's safe for 690 V systems with margin. The breaker holds its full 400 A rating up to 50 °C ambient; above that it derates linearly to 300 A at 70 °C — important if you're packing this into a hot enclosure with other heat sources.
Panel fit and integration
Footprint is 248 mm tall by 138 mm wide by 110 mm deep — standard SENTRON 3VA2 frame size. Mounts on a DIN rail or with screw-mount lugs; the 110 mm depth leaves room for rear-connected busbars in a typical distribution panel. Comes with 2 auxiliary switches, 1 trip alarm switch, and 1 electrical alarm switch (HQ type) factory-installed — enough for remote status indication without adding accessory kits. The undervoltage release (UVR) is also built in, so you get automatic dropout on voltage loss without a separate shunt trip module.