What this 400 A MCCB carries — and where it fits
The Siemens SENTRON 3VA2440-5HN32-0DL0 is a 3-pole molded case circuit breaker rated for 400 A continuous current (Iu) with an ETU350 electronic trip unit, sized for line protection in distribution panels and motor control centers. Its 187 kA breaking capacity at 240 V AC drops to 121 kA at 415 V and 440 V, then to 75.6 kA at 500 V and 17 kA at 690 V — so the voltage class of your bus determines which fault level this breaker can interrupt. Rated insulation voltage is 800 V (Ui).
Thermal derating and ambient limits
The breaker carries the full 400 A from 40 °C through 50 °C without derating. At 55 °C it drops to 384 A, at 60 °C to 376 A, at 65 °C to 368 A, and at 70 °C to 360 A. Operating ambient range is -25 °C to +70 °C; storage range is -40 °C to +80 °C. Maximum power loss is 66 W.
Auxiliary contacts and undervoltage release
This variant ships with an undervoltage release (UVR) as the auxiliary release, plus a contact block carrying 2 auxiliary switches, 1 trip alarm switch, and 1 electrical alarm switch (HQ type). The integrated auxiliary trip is order code 3VA9608-0BB25; the supplied basic switch is 3VA2440-5HN32-0AA0. Latching endurance is rated at 15,000 operations.
Panel fit — dimensions
The breaker measures 248 mm high, 138 mm wide, and 110 mm deep. It mounts on a DIN rail or directly to a backplate in a standard distribution panel or motor control center enclosure.