Upper incoming line, lower outgoing line, main circuit on the left, control circuit on the right, horizontal and vertical. The exposed laying can take the sheath line, or through the pipe and trunking. Whether in a home or an industrial facility, this box keeps your electrical setup organized, functional, and efficient. The wiring busbar in the box of the home distribution box shall be set with zero line, protective grounding wire and phase line. Hey, in this article we are going to see the Single Phase Distribution Box Wiring Diagram and Connection Procedure. The use of Yellow/Green bi-color wire for any other purpose is.