What this MCCB does for a panel
The Siemens SENTRON 3VA1332-7EF42-0AA0 is a 4-pole molded case circuit breaker rated for 320 A continuous at 40 °C, with a TM240 thermal-magnetic overcurrent release. It's built for line protection in distribution panels where you need high interrupting capacity — 440 kA at 240 V, 242 kA at 415 V, and still 17 kA all the way up at 690 V. That kind of SCCR headroom means it can sit upstream of a fault without taking the whole feeder down, which is the whole point of selective coordination in an industrial plant.
Thermal derating and real-world current
The 320 A rating holds flat from 40 °C through 50 °C, then starts to taper: 313 A at 55 °C, 306 A at 60 °C, 299 A at 65 °C, and 292 A at 70 °C. If you're stuffing this into a hot panel — say, next to a drive or a transformer — the 70 °C figure is the one to size against. The rated insulation voltage is 800 V, and the maximum operating ambient is 70 °C, with storage down to -40 °C and up to 80 °C.
Mounting and footprint
The breaker measures 248 mm high, 184 mm wide, and 110 mm deep — a 4-pole frame that'll need a solid backplate or DIN-rail adapter. The front face carries an IP40 rating, so it's fine for a clean indoor panel but not for washdown areas. Power loss at full load is 80.1 W, which adds to your enclosure's thermal load calculation.