What this MCCB is and where it fits
The Siemens SENTRON 3VA1140-5MH32-0AA0 is a 3-pole molded case circuit breaker (MCCB) designed specifically for starter protection — meaning it's built to handle the high inrush and locked-rotor currents of motor circuits, not just general distribution loads. Its TM120M thermal-magnetic release provides inverse-time overload protection (thermal element) and instantaneous short-circuit response (magnetic element), with the 120M designation indicating a fixed magnetic trip threshold suitable for motor starting profiles. Rated 40 A continuously at 40 °C ambient, it derates to 37 A at 70 °C — a thermal curve worth checking if this breaker lands in a crowded, uncooled enclosure. The rated insulation voltage is 800 V, and the interrupting ratings climb to 187 kA at 240 V AC, 121 kA at 415 V, 75.6 kA at 440 V, and 7.5 kA at both 500 V and 690 V. That 187 kA figure at 240 V is exceptional — it means this breaker can be applied on high-fault-capacity services without cascading upstream fuses. Front face carries IP40 protection — fine for a clean panel interior, but not rated for washdown or outdoor exposure. No undervoltage release, no ground-fault monitoring, no communication module on this variant; it's a straight electromechanical breaker with no auxiliary electronics.
Panel integration and mounting
Dimensions are 130 mm high, 76.2 mm wide, 70 mm deep — a compact 3-pole footprint that fits standard DIN-rail or screw-mount panel layouts. The 76.2 mm width (3 inches) matches the typical 3-pole MCCB slot in a SENTRON distribution board or motor control center. No trip indicator on the front face, so visual status checking requires a panel door with a window or a separate auxiliary contact block.