SENTRON 3VA1225-5FF42-0JC0 — 125 A MCCB with shunt trip
The 125 A frame carries a 187 kA interrupting rating at 240 V, dropping to 121 kA at 415 V, 75.6 kA at 440 V, 30 kA at 500 V, and 17 kA at 690 V. That's a strong short-circuit curve — useful for panels fed from large transformers or generator paralleling where fault currents run high. Thermal derating is flat at 250 A from 40 °C through 50 °C, then steps down: 243 A at 55 °C, 237 A at 60 °C, 230 A at 65 °C, 223 A at 70 °C.
The 2.76 in × 5.51 in × 6.22 in translates cleanly into existing cutouts if you're swapping an older frame. If the breaker lives in an unheated enclosure in a cold climate, the -25 °C floor is fine for most industrial sites.