The Siemens SENTRON 3VA2340-7HN32-0AC0 is a 3-pole molded case circuit breaker (MCCB) rated for 400 A continuous current, designed for line protection in distribution panels. Its interrupting capacity hits 330 kA at 240 VAC and 242 kA at 415 VAC, so it handles high-fault utility feeds without cascading upstream — that's the number that decides whether this breaker clears a bolted fault or the main switchgear takes the hit.
Breaking capacity and thermal derating
Breaking capacity drops as voltage climbs: 330 kA at 240 V, 242 kA at 415 V and 440 V, 187 kA at 500 V, and 7.5 kA at 690 V. That 7.5 kA at 690 V is the weak point — if your system runs 690 V with available fault current above that, this breaker isn't the right pick. Continuous current holds at 400 A up to 50 °C, then derates to 385 A at 55 °C, 370 A at 60 °C, 355 A at 65 °C, and 340 A at 70 °C. In a hot panel near a transformer or drive, use the 70 °C figure for sizing.
Auxiliary switch configuration and power loss
This variant ships with two auxiliary switches (HQ type) installed — no undervoltage release, no ground-fault monitoring, no communication module. Maximum power loss is 96 W, which matters for enclosure heat rise calculations. Operating temperature range is -25 °C to 70 °C; storage range is -40 °C to 80 °C.
Physical fit and panel integration
Dimensions are 248 mm high, 138 mm wide, 110 mm deep. The 138 mm width is the critical panel cutout dimension — verify it clears adjacent breakers or busbar shrouds. Depth of 110 mm includes the arc-chamber volume; leave clearance for outgoing cable bends and the auxiliary switch wiring.