What this breaker is and where it fits
The Siemens SENTRON 3VA2440-6HN32-0AJ0 is a 3-pole molded case circuit breaker (MCCB) rated for 400 A continuous at 40 °C through 70 °C — no derating needed across that range. Breaking capacity hits 242 kA at 240 VAC and 187 kA at 415 VAC, which puts it in the high-interrupting class for large distribution or industrial feeder panels. It is designed for line protection (no ground-fault or undervoltage release built in), and ships with a factory-fitted basic switch variant 3VA2440-6HN32-0AA0 plus 2 auxiliary switches and 1 trip alarm switch.
Breaking capacity — what the numbers mean for your panel
At 240 V the breaker interrupts 242 kA symmetrical; at 415 V and 440 V it holds 187 kA; at 500 V it drops to 121 kA; at 690 V it is still rated 9 kA. These are the maximum fault currents the MCCB can safely clear without welding or rupturing. For a 400 A feeder on a 480 V system the 187 kA rating at 415 V gives ample SCCR headroom for most industrial switchboards — coordination studies should verify the upstream transformer impedance and available fault current, but this breaker will not be the weak link in the chain.
Physical fit and panel integration
Dimensions: 248 mm high, 138 mm wide, 110 mm deep. It mounts on a DIN rail or directly to a backplate via the MCCB's integral mounting feet. The 3-pole footprint is standard for this class; verify the busbar or lug kit spacing matches the 138 mm width before panel layout.