What this 250 A MCCB delivers
The Siemens 3VA1225-5GF42-0HC0 is a SENTRON molded case circuit breaker rated for 250 A continuous current across a 4-pole construction, carrying a TM240 thermal-magnetic release that handles overload and short-circuit protection in one package. Breaking capacity hits 187 kA at 240 V, 121 kA at 415 V, 36 kA at 440 V, and 17 kA at 690 V — that's serious fault-interruption headroom for a 250 A frame, meaning it can ride through high-fault scenarios without cascading upstream gear. Rated insulation voltage is 800 V.
Thermal derating and real-world loading
The breaker holds its full 250 A rating from 40 °C through 50 °C ambient — no derating needed in a typical warm panel. At 55 °C it drops to 243.3 A, at 60 °C to 236.5 A, at 65 °C to 229 A, and at 70 °C to 223 A. If your panel runs hot (say, 55 °C inside the enclosure), plan for 243 A continuous load instead of the nameplate 250 A. That's a 2.7 % reduction — not a showstopper, but worth noting in the load schedule.
Built-in auxiliaries and release options
Comes with 2 auxiliary switches (HQ version) for status feedback to a PLC or annunciator, plus a shunt trip (STL) for remote tripping via a control signal — no undervoltage release fitted on this variant. The integrated auxiliary trip order code is 3VA9688-0BL30, which is the factory-matched accessory for this breaker frame.
Physical fit and panel integration
Dimensions are 70 mm deep, 140 mm wide, 158 mm tall — a standard 4-pole MCCB footprint that bolts into a SENTRON 3VA mounting base or panel-mount kit. Front protection is IP40, so it's fine in a closed enclosure but not washdown-rated. No communication module, no ground-fault monitoring, no phase-failure detection on this order code — it's a straight line-protection breaker with a shunt trip for remote disconnect. If you need those extras, you're looking at a different 3VA variant.