The three-pole frame handles up to 242 kA at 240 V, 187 kA at 415 V, and still holds 40 kA at 690 V, so it's sized for high-fault panels where you need selectivity downstream of a transformer or a main bus.
The 250 A rating holds flat from 40 °C through 50 °C, then derates to 240 A at 55 °C and 225 A at 70 °C. That's a clean thermal curve — if your panel ambient stays under 50 °C, you get full ampacity with no head-scratching. The ETU350 electronic trip gives you adjustable overload and short-time protection bands, which matters when coordinating with downstream breakers or fused disconnects. Breaking capacity drops as voltage climbs: 242 kA at 240 V, 187 kA at 415/440 V, 121 kA at 500 V, 40 kA at 690 V.