Above that, the thermal curve drops to 243 A at 55 °C, 237 A at 60 °C, 230 A at 65 °C, and 223 A at 70 °C — so if this breaker lives in a warm cabinet, the actual continuous current it can handle is lower than the nameplate 250 A.
Breaking capacity and interrupting duty
The interrupting rating depends on the system voltage: 121 kA at 240 V, 75.6 kA at 415 V, 52.5 kA at 440 V, 17 kA at 500 V, and 11.9 kA at 690 V. For a 480 V panel (common in North America), the relevant figure is the 440 V or 500 V rating — interpolate conservatively.
Dimensions: 105 mm wide, 158 mm high, 70 mm deep.