Ratings and what they mean for the panel
The 3VA1225-5EF42-0DA0: The 250 A rating at 40 °C is the continuous current the breaker carries without tripping in a 40 °C ambient — typical for a non-derated panel. Above that, the thermal curve steps down: 243 A at 55 °C, 237 A at 60 °C, 230 A at 65 °C, 223 A at 70 °C. If your enclosure runs hot, size the load to the derated figure, not the 40 °C headline. The 187 kA interrupting rating at 240 V is the maximum fault current this MCCB can safely clear at that voltage. At higher voltages the capacity drops: 121 kA at 415 V, 75.6 kA at 440 V, 30 kA at 500 V, 17 kA at 690 V. Verify the available fault current at your service voltage — the 240 V number alone does not apply at 480 V. Rated insulation voltage is 800 V, so the breaker is suitable for 690 V systems with margin. Power loss at rated load is 59.5 W — account for that heat in the enclosure thermal calculation, especially in a multi-breaker lineup.
Integration and mounting
Footprint is 140 mm wide, 158 mm high, 70 mm deep — a standard SENTRON 3VA frame size for 250 A. Mounts on a DIN rail or direct panel. The 4-pole configuration (three phases plus neutral) is typical for a 3-phase + N distribution board. The undervoltage release (UVR) trips the breaker when control voltage drops, used in emergency-stop or undervoltage protection schemes.