Three poles, ETU320 electronic trip unit, and a breaking curve that starts at 330 kA at 240 V and holds 242 kA through 440 V before dropping to 6.3 kA at 690 V.
Thermal derating — the real ampacity
At 55 °C it's 241 A; at 60 °C, 232 A; at 65 °C, 222 A; at 70 °C, 213 A. That's a clean, linear derate — no cliff. If your panel hits 60 °C (common in enclosed MCCs with transformer heat), you're working with 232 A continuous, not 250. Plan the branch circuit load accordingly. Maximum power loss is 48 W — that's the heat the breaker dumps into the enclosure at full load, so factor it into your thermal budget.