It carries a continuous current rating of 250 A at 40 °C, and that rating holds flat through 50 °C — you only start seeing derating above that, dropping to 243 A at 55 °C and 223 A at 70 °C. The interrupting capacity is substantial: 121 kA at 240 V, 75.6 kA at 415 V, and still 11.9 kA at 690 V, which covers most industrial low-voltage fault levels without needing a current-limiting upstream device.
The 250 A frame with a TM240 release means this breaker is sized for a 250 A bus or feeder, but the thermal-magnetic trip unit is adjustable — the 'TM240' designation indicates the thermal element is calibrated for a 240 A nominal, with magnetic pickup typically around 10x In. That 121 kA interrupting rating at 240 V is the key number for North American panels where the available fault current can hit 100 kA; at 415 V (common in industrial plants outside North America) it still clears 75.6 kA.
The supplied basic switch is order code 3VA12254EF420AA0, meaning the internal switching mechanism is a replaceable sub-assembly if the main contacts wear.