400 A MCCB with ETU320 — selectivity and SCCR headroom
The Siemens SENTRON 3VA2440-6HL32-0CC0 is a 3-pole molded case circuit breaker rated for a continuous current Iu of 400 A, with a maximum breaking capacity of 242 kA at 240 V AC. At 415 V and 440 V it still holds 187 kA, and at 690 V it drops to 40 kA, so the voltage-dependent curve governs where you place it in the distribution. The overcurrent release is an ETU320, a microprocessor-based trip unit that supports LSIG (long-time, short-time, instantaneous, ground-fault) protection profiles — though this particular variant ships without ground-fault monitoring.
Above that, it derates: 384 A at 55 °C, 376 A at 60 °C, 368 A at 65 °C, and 360 A at 70 °C. The 110 mm depth is the body depth behind the panel — relevant when you're checking clearance to the rear gland plate or a back-mounted busbar system. Maximum power loss is 66 W, which matters for thermal rise calculations in a sealed enclosure.
The auxiliary contact block fitted is a 2-changeover HQ type (order code 3VA9608-0BB24), and the basic switch assembly carries the code 3VA2440-6HL32-0AA0. If you're replacing the trip unit or the aux block separately, those are the service-part order codes to reference.