Connect the phase and neutral wires from the input power supply to the input of the Main MCB. Hey, in this article we are going to see the Single Phase Distribution Box Wiring Diagram and Connection Procedure. And all the switching and protective devices are installed in the. A distribution box is a low-voltage electrical enclosure that receives incoming power and distributes it safely to multiple outgoing circuits through protective and switching devices such as MCBs, RCDs, RCBOs, fuses, isolators, busbars, neutral bars, earth bars, and surge protective devices. Without it, managing power would be messy, unsafe, and inefficient.