What this 400 A MCCB carries — and where it fits
The Siemens 3VA2440-5HN32-0HH0 is a SENTRON molded case circuit breaker rated for 400 A continuous at 40 °C, on a 4800 A frame. That frame rating means the breaker's mechanical and thermal capacity is sized for the full 4800 A interrupting duty — the 400 A continuous setting is a thermal-magnetic or electronic trip threshold, not a hardware limit. At 240 V it clears 187 kA; at 415 V it still holds 121 kA, which puts it comfortably into the high-fault category for large distribution switchboards or transformer secondaries. Three-pole construction, line-protection design — this is the main breaker role, not a feeder or motor-circuit protector. The 3VA2440-5HN32-0HH0 carries a shunt trip (STL) for remote opening and comes pre-fitted with two auxiliary switches plus one trip-alarm switch HQ, so you get both status feedback and a separate alarm contact on a fault trip. The continuous rating holds flat from 40 °C through 70 °C — no derating curve to calculate in a warm enclosure. Max power loss is 63.5 W, which matters for heat buildup in a sealed panel.
Interrupting capacity across voltage levels
The SCCR drops as line voltage climbs: 187 kA at 240 V, 121 kA at 415 V and 440 V, 75.6 kA at 500 V, and 9 kA at 690 V. At 690 V the 9 kA figure is the breaker's limit — if your system fault current exceeds that at this voltage, you need a different frame or a current-limiting upstream device. For most 400 V-class industrial distribution, 121 kA is ample headroom.
Panel fit and environmental range
Dimensions: 248 mm high, 138 mm wide, 110 mm deep. That 110 mm depth is the body only — account for the shunt trip and auxiliary switch wiring projection when laying out the gland plate. Operating temperature spans -25 °C to 70 °C; storage range is -40 °C to 80 °C. No undervoltage release or communication module on this variant, so no extra wiring for those functions.