Derating and thermal reality
The 400 A rating holds flat up to 50 °C ambient. Above that, the derating is gradual: 384 A at 55 °C, 376 A at 60 °C, 368 A at 65 °C, 360 A at 70 °C. That's a 10 % drop from 50 to 70 °C — typical for a molded-case frame of this size. If your panel ambient runs hot, you'll want to factor that into the bus and cable sizing. The operating range is -25 °C to 70 °C, storage from -40 °C to 80 °C.
Built-in auxiliaries and releases
This variant ships with an undervoltage release (UVR) as the auxiliary release — part number 3VA9608-0BB11 — and two HQ auxiliary switches. The UVR is a common safety requirement: if control power drops, the breaker opens. No voltage trigger, no shunt trip. The auxiliary switches are wired into the panel's status monitoring. The basic switch itself is the 3VA2440-6HL32-0AA0.