Wiring requirements of distribution box 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. However, the key to. In modern electrical systems, cable distribution boxes (also known as electrical distribution boxes or distribution boxes) play a crucial role as the key hub for managing, distributing, and protecting circuits. You must make safety your top priority when working with low voltage distribution boxes.