What this MCCB is and what it handles
The Siemens SENTRON 3VA2340-6KP32-0CH0 is a 3-pole molded case circuit breaker (MCCB) rated for 400 A continuous current at 40 °C, designed for line protection in industrial power distribution. Its interrupting capacity hits 242 kA at 240 V AC and still holds 187 kA at 415 V and 440 V, dropping to 121 kA at 500 V and 7.5 kA at 690 V — so on a 480 V wye service you've got serious fault-current headroom for high-capacity feeds. The 400 A frame means it's sized for main or large feeder breakers, not branch circuits.
Derating and thermal reality
The 400 A rating holds flat from 40 °C through 50 °C. At 55 °C it derates to 375 A, at 60 °C to 350 A, at 65 °C to 325 A, and at 70 °C to 300 A. If your panel ambient runs hot — say a packed enclosure near a furnace line — you lose 100 A off the top. Plan the load accordingly or oversize the frame. Maximum power loss is 98.5 W, which adds to the enclosure heat budget.
Built-in auxiliaries and releases
This variant ships with an undervoltage release (UVR) and a 2-auxiliary-switch plus 1-trip-alarm-switch HQ configuration. That means you get remote status indication and undervoltage protection without adding external relays. Communication function is present, so it can talk to a BMS or PLC for power monitoring. The basic switch is order code 3VA2340-6KP32-0AA0 — the UVR and aux switches are factory-integrated, not field-addable on this SKU.
Physical fit and environment
Dimensions are 248 mm high, 138 mm wide, 110 mm deep. It's a panel-mount MCCB — no DIN rail, so plan for bolt-on bus bars or cable lugs. Operating temperature range is -25 °C to 70 °C; storage from -40 °C to 80 °C. The trip indicator is present, which helps during troubleshooting: you see a mechanical flag or button pop when the breaker trips on overcurrent or short circuit.