What this MCCB delivers
The Siemens SENTRON 3VA1225-5EF32-0AB0 is a 3-pole molded case circuit breaker (MCCB) with a TM240 thermal-magnetic release, rated for line protection. It carries a continuous current of 250 A at 40 °C, derating to 223 A at 70 °C — useful when the breaker lives in a warm panel or next to other heat sources. Interrupting capacity reaches 187 kA at 240 V AC, 121 kA at 415 V, and 75.6 kA at 440 V, so it handles high-fault utility feeds or transformer-secondaries without cascading upstream. Rated insulation voltage is 800 V, and maximum power loss sits at 57 W — a figure to factor into enclosure thermal calculations when grouping multiple breakers. Dimensions are 158 mm high, 105 mm wide, 70 mm deep, fitting standard SENTRON panel cutouts.
Mounting and integration
The 3VA1225-5EF32-0AB0 mounts on a DIN rail or directly to a panel backplate via the SENTRON base. Its 105 mm width occupies three standard 35 mm module spaces. The TM240 release is fixed-trip, not adjustable, so the breaker is sized for a specific load and should not be swapped into a circuit with a different full-load ampacity without verifying the trip curve.