What this breaker is and what the ratings mean for your panel
The Siemens SENTRON 3VA2440-7HL32-0AC0 is a 3-pole molded case circuit breaker (MCCB) rated for 400 A continuous current (Iu) with an ETU320 electronic trip unit. That 400 A rating holds across 40 °C to 50 °C ambient without derating — only starts tapering at 55 °C (384 A) and drops to 360 A at 70 °C, so it handles warm enclosures better than many thermal-magnetic breakers. The ETU320 gives you adjustable overload and short-circuit protection curves, not just a fixed bimetal — useful when coordinating with downstream breakers on a feeder. Breaking capacity hits 330 kA at 240 V, 242 kA at 415 V and 440 V, 187 kA at 500 V, and 52.5 kA at 690 V. At 415/440 V, that 242 kA is well above typical utility fault levels — this breaker is sized for high-fault industrial services like transformer secondaries or large motor control centers where the available short-circuit current is serious. The IP40 front protection is standard for enclosed panel mounting; the breaker itself isn't meant for open wet locations. The unit comes with 2 auxiliary switches (HQ type) built in — that's enough for remote status and a separate alarm signal without adding a side-mount module. No undervoltage release, no shunt trip, no ground-fault monitoring on this variant; if you need those, you're looking at a different 3VA2 order code. Power loss maxes at 63.5 W, so factor that into your panel thermal budget if you're packing several breakers in a small enclosure.
Panel fit and dimensions
The 3VA2440-7HL32-0AC0 measures 248 mm high, 138 mm wide, and 110 mm deep — a standard 3-pole MCCB footprint for the 400 A frame. It mounts with four screws on a backplate or a mounting plate; no DIN rail on this frame size. Make sure your enclosure depth clears the 110 mm plus wiring space for the lugs — 200 mm minimum internal depth is a safe rule of thumb.