Breaking capacity and selectivity
The 3VA1225-4EF42-0DA0: This MCCB delivers 121 kA breaking capacity at 240 V, 75.6 kA at 415 V, 25 kA at 440 V, and 11.9 kA at 690 V — figures that govern fault-clearing capability in low-voltage distribution. The 250 A frame with TM240 release means the thermal pickup is fixed at 240 A, magnetic trip at a multiple of that, so it coordinates downstream with smaller branch breakers without nuisance tripping on motor inrush.
Thermal derating and ambient limits
Rated 250 A up to 50 °C ambient; above that derates linearly to 223 A at 70 °C. The operating range is -25 °C to 70 °C, storage from -40 °C to 80 °C. For panels in hot environments — near furnaces or in unconditioned enclosures — the 55 °C derated figure of 243.3 A is the real limit to design to.
Integrated undervoltage release
Comes with an undervoltage release (UVR) as the auxiliary release type — part number 3VA9608-0BB25 for the integrated trip accessory. No auxiliary contact version is fitted, so if you need remote status feedback, plan for a separate auxiliary switch block. Protection class IP40 on the front, suitable for panel-mount indoor use.