What it is and what it does
The Siemens SENTRON 3VA1140-3EF32-0HA0 is a 3-pole molded case circuit breaker (MCCB) rated 40 A at 40 °C, designed for line protection in distribution panels and industrial switchgear. Its TM240 thermal-magnetic release handles overload and short-circuit protection without external control power, and the integrated shunt trip (STL) allows remote tripping for emergency-off or supervisory circuits. Breaking capacity climbs to 75.6 kA at 240 VAC and stays at 52.5 kA at 415 VAC — enough for high-fault utility feeds. At 690 VAC it still interrupts 11.9 kA, covering most industrial motor branch circuits. Rated insulation voltage is 800 V, so it can be applied in 480/277 V and 600 V panels with margin. Power loss at rated load is 10.8 W maximum — relevant for thermal budgeting in a sealed enclosure. The 70 mm depth and 76.2 mm width match the standard SENTRON 3VA footprint, so it swaps into existing panel layouts without re-drilling.
Where it fits
Mounts on a DIN rail or panel-mount base in a standard distribution board or motor control center. The 3-pole design covers three-phase loads — feeders, motor branch circuits, or main incomers in sub-distribution. Operating temperature range is -25 °C to 70 °C, storage from -40 °C to 80 °C, so it's fine for unconditioned electrical rooms.