Inside the box, you'll find things like circuit breakers, busbars, terminal blocks, and wires. These parts control and distribute the electricity to different circuits safely. Every wire in your home — every socket, every light, every appliance circuit — traces back to a single grey box on the wall: the distribution board, also called a consumer unit or, in older installations, a fuse box. It is the most critical component in any electrical installation, and. A distribution board or distribution box is where the main power supply is distributed to multiple loads. Single Phase Distribution Box generally consists of Double Pole MCBs, Single Pole MCBs, and RCCBs.