What this MCCB does on the line
The Siemens 3VA1140-4EF32-0JC0 is a SENTRON molded case circuit breaker (MCCB) rated for 40 A continuous at 40 °C, with three poles and a design focus on line protection — meaning it sits at the feeder or main distribution point, not on a motor branch. Its interrupting capacity hits 121 kA at 240 V and 75.6 kA at 415 V, which gives selectivity headroom downstream: you can coordinate a 25 kA panelboard behind this breaker without worrying about a fault cascading past the main.
The breaker holds its full 40 A rating up to 50 °C ambient; above that it derates gradually to 37 A at 70 °C. The 70 mm depth and 76.2 mm width are standard for the 3VA1 frame, so it drops into a DIN-rail or screw-mounted footprint without re-drilling the backplate. Maximum power dissipation is 10.8 W, which is modest for a 40 A MCCB — useful to know when calculating enclosure ventilation. The rated insulation voltage of 800 V covers 480Y/277 V and 600 V delta systems with margin.