Its three poles handle three-phase circuits up to 800 V insulation voltage (Ui). The 121 kA breaking capacity at 240 V gives substantial fault-interrupting headroom at low-voltage distribution levels; at 415 V it still clears 75.6 kA, and at 690 V it holds 11.9 kA — enough for most industrial secondary-distribution panels.
Ratings that drive the fit
The TM240 release means the thermal pickup is fixed at 125 A (the Iu rating), with magnetic trip factory-set to a multiple of that — typical for motor or feeder protection where you want a defined short-circuit threshold. The 125 A holds across 40 °C to 50 °C ambient without derating; above that it steps down to 120 A at 55 °C, 117.5 A at 60 °C, 115 A at 65 °C, and 112.5 A at 70 °C.
Dimensions are 130 mm high, 76.2 mm wide, 70 mm deep — a standard 3-pole MCCB footprint that fits most DIN-rail or panel-mount enclosures without re-drilling.