What this MCCB delivers
The SENTRON 3VA1225-6GF42-0DB0 is a 4-pole molded case circuit breaker rated at 250 A continuous, with a robust interrupting capacity that scales with system voltage — 220 kA at 240 V, 154 kA at 415 V, 75.6 kA at 440 V, 30 kA at 500 V, and 17 kA at 690 V. That means it handles high-fault scenarios on the secondary side of a distribution transformer or at a main feeder without cascading upstream. The rated insulation voltage is 800 V, so it's comfortable in 690 V line-to-line systems. Thermal derating is mild up to 50 °C — still 250 A — then drops to 243 A at 55 °C, 237 A at 60 °C, 230 A at 65 °C, and 223 A at 70 °C. If your panel ambient runs hot, you lose less than 11 % at the top end. Power loss at full load is 59.5 W, which matters for enclosure heat rise calculations.
Panel fit and integration
Dimensions are 158 mm high, 140 mm wide, 70 mm deep — a compact footprint for a 250 A frame. The 4-pole design covers three-phase plus neutral, common for main disconnects or feeder breakers in North American and European distribution panels. It ships with an undervoltage release (UVR) and two auxiliary switches (HP type), so you get remote status and undervoltage protection without adding external relays. Operating temperature range is -25 °C to 70 °C; storage from -40 °C to 80 °C. That covers most indoor and sheltered outdoor enclosures.