Rated for the high-fault panel
The Siemens SENTRON 3VA2440-7HL32-0KH0 is a 3-pole molded case circuit breaker rated for a continuous current Iu of 400 A, with a breaking capacity of 330 kA at 240 VAC. That 330 kA figure at the lower voltage tells you this breaker is built for high-fault installations — typically transformer secondaries or large bus risers where available fault current exceeds what a standard MCCB can interrupt. The breaking capacity scales down as voltage rises: 242 kA at 415/440 V, 187 kA at 500 V, and still 52.5 kA at 690 V, which covers most industrial distribution voltages. The ETU320 electronic trip unit handles the overcurrent protection curve. This is a line-protection version — no ground-fault monitoring, no communication module, no undervoltage release. It ships with a shunt trip (STL) for remote opening and an auxiliary contact block configured as 2 auxiliary switches plus 1 trip alarm switch (HQ designation). The auxiliary release is a separate order: 3VA9688-0BL33.
Thermal derating and panel fit
Rated continuous current holds at 400 A from 40 °C up through 50 °C ambient. 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. If the panel runs hot — say a non-ventilated enclosure near a furnace line — you lose 40 A at the top end. The maximum power loss at full load is 63.5 W, which matters for enclosure heat rise calculations. Physical footprint: 248 mm tall, 138 mm wide, 110 mm deep. That depth is the body only — factor in the shunt trip and auxiliary switch wiring clearance on the side. Operating temperature range is -25 °C to 70 °C; storage from -40 °C to 80 °C.