The Siemens SENTRON 3VA1340-4GE42-0AA0 is a 400 A, 4-pole molded case circuit breaker (MCCB) with a TM220 thermal-magnetic overcurrent release, designed for line protection in distribution panels. It carries a short-circuit breaking capacity of 121 kA at 240 V AC and 75.6 kA at 415 V AC, with a rated insulation voltage of 800 V. The IP40 front protection suits enclosed panel mounting.
SCCR and thermal derating
The interrupting ratings step down with system voltage: 121 kA at 240 V, 75.6 kA at 415 V and 440 V, 52.5 kA at 500 V, and 11.9 kA at 690 V. That means this breaker handles high available fault current on lower-voltage services — common in North American 240 V delta or 480Y/277 V panels — but the 690 V figure is modest; for high-voltage feeders, a larger frame or current-limiting fuse may be needed upstream. Thermal derating is flat at 400 A from 40 °C through 50 °C, then drops to 392 A at 55 °C, 384 A at 60 °C, 376 A at 65 °C, and 367 A at 70 °C. If the panel ambient runs above 50 °C, size the load side accordingly.