What it is and what it does
The Siemens 3VA2340-6KP32-0AJ0 is a SENTRON molded case circuit breaker (MCCB) rated for line protection in industrial distribution panels. It carries a continuous current of 400 A at 40 °C through three poles, with a maximum breaking capacity of 242 kA at 240 V and 187 kA at 415 V — figures that tell you it will clear a bolted fault on a large transformer secondary without the arc re-striking or the case rupturing.
Ratings that matter in the panel
Continuous current holds at 400 A from 40 °C up to 50 °C, then derates to 375 A at 55 °C and 300 A at 70 °C — so if the panel ambient runs above 50 °C, you need to account for the drop in the load schedule. The 3-pole design handles three-phase circuits, and the 110 mm depth fits standard MCCB mounting footprints in most switchboards. Breaking capacity steps down with voltage: 242 kA at 240 V, 187 kA at 415 V and 440 V, 121 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 and fault current exceeds that, this breaker is not the right choice. Power loss is 96 W maximum at rated current, which adds to the panel heat load. The operating temperature range spans -25 °C to 70 °C, with storage from -40 °C to 80 °C.
Panel integration notes
Mounts in the standard MCCB footprint on a DIN rail or direct-panel mount. The 138 mm width and 248 mm height leave room for side-mounted auxiliary switches — the base breaker comes with 2 auxiliary switches plus 1 trip alarm switch. A communication function is built in, so it can report status to a BMS or PLC without an add-on module.