Breaking capacity hits 75.6 kA at 240 V, 52.5 kA at 415 V, and still holds 11.9 kA at 690 V — that's real fault-current headroom for industrial service where the available fault current can be stiff.
Thermal derating and what it means for your load
This breaker is rated 100 A all the way up to 50 °C — that's a solid continuous rating for most panel interiors. Above that it starts to derate: 98 A at 55 °C, 96 A at 60 °C, 94 A at 65 °C, and 91 A at 70 °C. If your panel sits near a hot motor or in a sun-baked cabinet, that 91 A at 70 °C is the number you size to, not the 100 A label. The maximum power loss is 25 W, so account for that heat in your enclosure thermal calculation.
Footprint and panel fit
The 4-pole width of 101.6 mm means it takes up about four 25 mm module spaces on a DIN rail — check your existing rail layout if you're swapping in a retrofit.