The front-terminal busbar connection keeps panel wiring clean, and the IP40 front face suits enclosed distribution boards where the operator side is behind a door.
The 125 A rated continuous current (Iu) sets the maximum load it can carry continuously without exceeding temperature limits. The 800 V rated insulation voltage (Ui) and 690 V AC / 500 V DC maximum operational voltages define the system voltage it can safely interrupt — common for 400 V three-phase distribution or 480 V industrial feeds. The short-time withstand ratings of 2 kA at both 0.5 s and 1 s tell you it can hold off fault current for that duration while an upstream breaker clears, but this is not a breaker itself; coordination relies on the upstream protective device.
Integration notes
The 70 mm depth, 76.2 mm width, and 130 mm height match the standard 3VA1 frame footprint, so it occupies the same DIN-rail or mounting-plate space as a 3-pole MCCB in the same series. The busbar connection on the front terminal means it accepts plug-in busbar links rather than lugged cable — verify your panel's busbar system compatibility before specifying.