Thermal derating and continuous current
The 250 A rating holds at ambient temperatures up to 50 °C. Above that, the breaker derates: 238 A at 55 °C, 225 A at 60 °C, 213 A at 65 °C, and 200 A at 70 °C. For a panel with internal temperature rise above 50 °C, size the load accordingly — the full 250 A is only available below that threshold.
Dimensions and panel fit
The breaker measures 181 mm high, 105 mm wide, and 86 mm deep. It mounts on a DIN rail or direct panel surface; the 105 mm width occupies three pole spaces at the standard 35 mm per pole. Verify enclosure depth against the 86 mm plus wiring clearance before committing the backplate layout.
Trip unit, auxiliaries, and communication
The ETU550 electronic trip unit provides adjustable overload and short-circuit protection curves. Two HQ auxiliary switches (3VA9608-0BB11) are integrated for status feedback. An undervoltage release (UVR) is fitted — the basic switch is order code 3VA2225-5JP32-0AA0, and the auxiliary trip module is 3VA9608-0BB11. Communication function is present, enabling integration with higher-level monitoring systems.
Environmental and electrical ratings
Rated insulation voltage Ui is 800 V. Operating temperature range is -25 °C to 70 °C; storage range is -40 °C to 80 °C. Maximum power loss at rated current is 50.5 W — account for this in enclosure thermal calculations. The breaker does not include a voltage trip, phase failure detection, or ground fault monitoring.