What this MCCB delivers — and what the ratings tell you
The Siemens SENTRON 3VA2340-7HN32-0AD0 is a 3-pole molded case circuit breaker (MCCB) rated for 400 A continuous current at 40 °C, designed for line protection in distribution panels. Its 330 kA breaking capacity at 240 V AC tells you it can safely clear a bolted fault on a high-capacity transformer secondary without the arc flashing upstream — that's the kind of interrupting rating you need when the available fault current is high and you're protecting a main feeder rather than a branch. The 400 A frame is thermally rated across a wide ambient range: it holds full rating up to 50 °C, then derates linearly to 340 A at 70 °C. That means in a hot panel — say, next to a drive cabinet or in a non-climate-controlled enclosure — you still get 340 A of headroom before the bimetal trips. The 96 W maximum power loss at full load is worth noting for enclosure thermal calculations; it's not trivial in a sealed box.
Panel fit and integration
Footprint is 248 mm tall by 138 mm wide by 110 mm deep — a standard 3-pole MCCB envelope that drops into most SENTRON panelboards and switchgear without re-drilling gland plates. The 3 auxiliary switches (HQ type) come factory-fitted, so you get remote status indication without adding an accessory later. No undervoltage release, no shunt trip, no ground-fault module on this variant — it's a straight line-protection breaker.