40 A MCCB with flat derating and high interrupt capacity
The Siemens SENTRON 3VA2140-8KQ32-0AA0 is a 3-pole molded case circuit breaker rated for 40 A continuous current, with a full-scale value of 40 A and an initial trip threshold of 16 A. It holds its 40 A rating flat across the entire operating ambient range from -25 °C to 70 °C — no derating curve to chase above 40 °C, which simplifies panel coordination in warm enclosures. Interrupting capacity runs from 440 kA at 240 V down to 52.5 kA at 690 V, giving you headroom for high-fault installations without stepping up frame size.
Breaking capacity and selectivity planning
At 415 V and 440 V this breaker clears 330 kA; at 500 V it still handles 220 kA. That puts it in the high-interrupt class for a 40 A frame — useful when the fault current at the panelboard exceeds typical 25–65 kA ranges. The 800 V rated insulation voltage means it can sit on a 480 V or 600 V system with margin. Ground-fault monitoring uses summation current formation on the L-conductor, so you get GF protection without an external module.
Integration notes
Mounts in a standard panel on a DIN rail or direct screw-mount — the 105 mm width and 86 mm depth fit SENTRON 3VA panel footprints. Communication function is built in, so you can wire it into a monitoring bus without an add-on module. Power loss maxes at 1.2 W — negligible heat contribution inside a sealed enclosure. Storage range from -40 °C to 80 °C covers cold warehouses and hot shipping containers.