SENTRON 3VA1225-6GF42-0KF0 — 250 A MCCB, line protection, active production
The Siemens SENTRON 3VA1225-6GF42-0KF0 is a 4-pole molded case circuit breaker rated for a continuous current of 250 A at 40 °C, designed for line protection in distribution panels and switchgear assemblies. 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. The breaker carries a shunt trip release (STL) for remote tripping and one auxiliary switch plus one trip alarm switch (HQ configuration), enabling status feedback to a PLC or SCADA system.
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. Dimensions are 158 mm height, 140 mm width, 70 mm depth — fits standard SENTRON 3VA mounting footprints and DIN-rail or screw-mount panel layouts.