The AC Distribution Box (ACDB), also called the AC Distribution Board, is a key part of an Electrical Distribution System. Its main job is to control and send out alternating current (AC) electricity from a main source to different circuits and devices in a building or installation. In the AC power system, as an important part of the power equipment, the AC distribution box mainly plays the following roles: Power distribution: The AC power distribution box distributes the high-voltage AC power from the. A distribution box is an important electrical device mainly used for the distribution and control of electric energy in a power system. Generally, the incoming line is AC 380V power supply. There are one or more main air switches in the distribution box.