The 250 A continuous rating holds at ambient temperatures up to 50 °C without derating; above that it drops to 243 A at 55 °C and 223 A at 70 °C. If your panel runs hot, the effective current is lower than the nameplate. Interrupting capacity varies sharply with system voltage: 220 kA at 240 V, 154 kA at 415 V, 75.6 kA at 440 V, 30 kA at 500 V, and 17 kA at 690 V. At 690 V the 17 kA figure is the limiting case; verify your available fault current against that number before specifying this breaker on a 690 V bus.
The 4-pole body takes up 140 mm of rail width; verify fill factor if retrofitting into an existing distribution board.