At 240 V it interrupts 75.6 kA; at 415 V that drops to 52.5 kA, so the available fault current at the panelboard is what decides the fit. The 70 mm depth and 50.8 mm width let it tuck into a standard MCCB slot without stealing extra DIN rail real estate.
Derating and thermal reality
This breaker holds its full 125 A rating from 40 °C up through 50 °C. At 55 °C it derates to 122 A, at 60 °C to 120 A, and at 70 °C to 114 A. That's a clean thermal curve — no surprise drop at 45 °C. Maximum power loss hits 18.74 W, which matters for heat buildup inside a sealed enclosure.
The 2-pole form factor and 50.8 mm width mean it fits the same footprint as other SENTRON 2-pole MCCBs; no panel rework needed if swapping from a similar unit.
No communication function, no motor drive option, no neutral conductor upgrade. Standard compliance documentation (CE, UL, IEC) is available from the manufacturer for this series.