SENTRON 3VA1225-6GF42-0KF0 — 250 A MCCB, line protection, active production
Its interrupting capacity reaches 220 kA at 240 V AC, 154 kA at 415 V, and 75.6 kA at 440 V — sufficient for high-fault-current installations like transformer secondaries or large motor control center feeders.
Thermal derating and power dissipation
Rated 250 A continuously up to 50 °C ambient; above that, derate to 243 A at 55 °C, 237 A at 60 °C, 230 A at 65 °C, and 223 A at 70 °C. Panel builders must account for this when packing breakers in a sealed enclosure. Maximum power loss is 57 W at rated load, which factors into enclosure thermal calculations and ventilation requirements.