The Siemens 3VA1125-3EF32-0KC0 is a SENTRON molded case circuit breaker (MCCB) designed for line protection in distribution panels. It's a 3-pole unit rated at 25 A continuous current at 40 °C, with a rated insulation voltage of 800 V. The key spec for a sourcing decision is the breaking capacity: 75.6 kA at 240 V, 52.5 kA at 415 V, and 32 kA at 440 V — that's the fault current it can safely interrupt without welding contacts or venting plasma. At 500 V and 690 V it still holds 11.9 kA, which covers most industrial motor-control panels.
The 3VA1125-3EF32-0KC0 comes with a factory-installed shunt trip (STL) release and two auxiliary switches (HQ type). That means it's ready for remote tripping and status feedback out of the box — no extra wiring of add-on modules on the bench. The 76.2 mm width and 70 mm depth fit the standard SENTRON 3VA panel footprint; if you're swapping into an existing 3VA cutout, the bus-bar centers and DIN-rail clip pattern are identical across the family. Power loss is 8.5 W maximum, so thermal rise inside a sealed enclosure is manageable with standard venting.