What this MCCB carries and where it fits
The Siemens SENTRON 3VA2340-6KQ32-0AA0 is a 3-pole molded case circuit breaker rated 400 A continuous at 40 °C, with an interrupting capacity of 242 kA at 240 V AC — that's the headline number for fault-clearing on a 240 V service. At 415 V it still handles 187 kA, and at 690 V the rating drops to 7.5 kA, so the SCCR you design to depends entirely on your line voltage. The ETU860 electronic trip unit gives you adjustable long-time pickup (0.8 s minimum) and short-time/instantaneous settings up to 4000 A, plus ground-fault monitoring via summation current formation on the L-conductor. Communication function is built in, so this breaker talks to a BMS or PLC without an add-on module.
Thermal derating and panel integration
The 400 A rating holds from 40 °C through 50 °C; above that it steps down — 375 A at 55 °C, 350 A at 60 °C, 325 A at 65 °C, 300 A at 70 °C. If your enclosure runs hot, size the breaker for the lower figure. The 3VA2340-6KQ32-0AA0 measures 248 mm high by 138 mm wide by 110 mm deep, which is a standard MCCB footprint for this class. Front IP40 keeps out tools and fingers; the rest of the body is open to the panel air for convection cooling. Power loss at full load is 96 W — account for that in your thermal budget if you're packing multiple breakers in a row.