What this MCCB carries — and where it stops
The Siemens 3VA1225-4EF32-0CH0 is a SENTRON molded case circuit breaker (MCCB) rated for 250 A continuous current, with a TM240 thermal-magnetic release that handles overload and short-circuit protection in one package. At 240 V it interrupts 121 kA; at 415 V that drops to 75.6 kA, and at 690 V it still clears 11.9 kA — so this breaker is sized for high-fault industrial distribution, not light commercial subfeeds. It's a 3-pole unit, line protection version (no voltage trigger, no ground-fault monitoring), with an undervoltage release built in and a 2-auxiliary-switch-plus-1-trip-alarm contact block onboard. The front face carries IP40 protection — fine inside a closed panel, but not for washdown areas.
Thermal derating — the real-world current
The 250 A rating holds solid from 40 °C up to 50 °C. At 55 °C it starts to taper: 243.3 A. By 70 °C you're down to 223 A. If this breaker sits in a hot enclosure near transformers or drives, size it off the 70 °C figure — the nameplate 250 A is only good if the ambient inside the panel stays under 50 °C.
Footprint and integration
The can measures 105 mm wide by 158 mm tall by 70 mm deep — a standard 3-pole MCCB footprint for a 250 A frame. Bolts onto a mounting plate or into a fixed chassis; no DIN-rail clip on this frame class. The undervoltage release coil draws its signal from a separate control circuit, so plan for an extra pair of wires back to the control transformer or UPS.