Its interrupting capacity hits 121 kA at 240 V AC and 75.6 kA at 415 V AC — numbers that matter when you're coordinating selectivity downstream of a transformer or a large motor starter.
Rated current holds at 125 A from 40 °C through 50 °C, then derates to 122 A at 55 °C, 120 A at 60 °C, 117 A at 65 °C, and 114 A at 70 °C. The interrupting curve is steep: 75.6 kA at 415 V drops to 52.5 kA at 440 V and 11.9 kA at 500 V or 690 V. At higher voltages, the breaker still clears faults, but the available fault current must stay under the lower rating.
The 3-pole footprint matches the standard SENTRON 3VA frame, so it swaps into existing cutouts without re-drilling.