Its interrupting capacity hits 121 kA at 240 V AC and 75.6 kA at 415 V AC — that's the fault-clearing muscle you need when the available short-circuit current is high and you want selectivity upstream without blowing the main. The basic switch assembly carries order code 3VA11124EF360AA0.
Mounting and fit — DIN-rail footprint, no surprises
Width is 76.2 mm (3 in), depth 70 mm (2.76 in), height 130 mm (5.12 in). If you're swapping into an existing panel, measure the mounting depth: 70 mm leaves room for rear-connected busbars without crowding the backplane.
Thermal derating — what the 125 A rating actually delivers
Above that it starts to taper: 122 A at 55 °C, 120 A at 60 °C, 117 A at 65 °C, and 114 A at 70 °C.