What this MCCB is and what it does
The Siemens SENTRON 3VA2440-7HL32-0KC0 is a 3-pole molded case circuit breaker (MCCB) rated for line-protection duty — meaning it sits at the incoming feeder or main distribution point, not on a motor branch. Its adjustable thermal-magnetic trip can be set between 600 A and 4800 A, which covers everything from a large secondary switchboard to a transformer primary. The interrupting capacity tells you where it can go: 330 kA at 240 V, 242 kA at 415 V and 440 V, 187 kA at 500 V, and 9 kA at 690 V. At the lower voltages it handles high-fault utility feeds; at 690 V the 9 kA figure means it's not a main breaker for a high-voltage industrial grid — that's a coordination limit to respect when you're building the selectivity study. The continuous current rating holds flat at 400 A from 40 °C through 70 °C ambient — no derating curve to chase in a warm enclosure. Power loss at full load is 63.5 W, which is manageable for a panel's thermal budget but worth checking if you're packing multiple breakers in a sealed cabinet.
Physical fit and panel integration
Dimensions are 248 mm high, 138 mm wide, 110 mm deep. That's a standard 3-pole MCCB footprint for the 400 A frame class — mounts on a mounting plate or DIN rail via the appropriate adapter, though at this frame size you're typically bolting it to a backplate with busbars, not snapping it onto a DIN rail. The breaker ships with a shunt trip (STL) auxiliary release and two HQ auxiliary switches built in — that's the -7HL32-0KC0 suffix telling you the internal accessory configuration. The basic switch variant is 3VA2440-7HL32-0AA0 if you ever need to reference the bare breaker without the auxiliaries.
Environmental and compliance range
Operating temperature spans -25 °C to 70 °C; storage range is -40 °C to 80 °C. The storage minimum is the one that matters if the breaker sits in an unheated warehouse before installation — it can handle the cold, just don't energize it below -25 °C.