Current derating and thermal limits
The 3VA1225-4EF32-0JH0: The 250 A rating holds from 40 °C through 50 °C. Above that, the breaker derates: 243 A at 55 °C, 237 A at 60 °C, 230 A at 65 °C, and 223 A at 70 °C. The maximum power loss is 57 W. Operating temperature range is -25 °C to 70 °C; storage range is -40 °C to 80 °C. If the panel ambient exceeds 50 °C, the continuous load must be reduced per the published curve — the datasheet values are the ones to use for sizing.
Auxiliary switching and shunt trip
This variant includes a shunt trip release (STL) for remote tripping, plus two auxiliary switches and one trip alarm switch (HQ configuration). The auxiliary switches signal breaker position; the alarm switch indicates a trip event. The breaker does not include an undervoltage release or ground-fault monitoring. Communication function is not fitted — this is a standalone MCCB, not a networked unit.
Physical fit and panel integration
Dimensions: 105 mm wide, 158 mm high, 70 mm deep. The width is the critical dimension for multi-pole grouping in a distribution panel — 105 mm per 3-pole unit is standard for this frame size. The depth of 70 mm (2.76 in) leaves clearance for rear-connected busbars or cable lugs. Mounting is via the molded-case base; no DIN-rail adapter is used at this frame size.