The Siemens SENTRON 3VA1225-4EF42-0KC0 is a 4-pole molded case circuit breaker (MCCB) rated for line protection, carrying 250 A continuously at 40 °C with no derating needed up to 50 °C — it holds 250 A flat across that range, then tapers to 223 A at 70 °C. Breaking capacity hits 121 kA at 240 V, so it handles high-fault utility feeds without cascading upstream.
Breaking capacity by voltage — what it means for panel coordination
At 415 V the breaker interrupts 75.6 kA, at 440 V it's 52.5 kA, at 500 V it drops to 17 kA, and at 690 V it's 11.9 kA. That's a steep curve above 440 V — if your service transformer secondary is 480 V with a 65 kA available fault current, this breaker's 17 kA at 500 V won't clear it. You'd need an upstream current-limiting fuse or a higher-rated frame. The 121 kA at 240 V is typical for large commercial or light industrial main breakers where the utility transformer is close.
Thermal derating and installation
Dimensions are 70 mm deep, 140 mm wide, 158 mm tall — a standard 4-pole MCCB footprint for DIN-rail or panel-mount. The 57 W maximum power loss at full load means you need some ventilation in a sealed enclosure; stacking multiple breakers side-by-side without spacing will raise internal ambient and accelerate derating. Rated insulation voltage is 800 V, so it's fine for 690 V systems with margin.