The system includes a main distribution box, sub-distribution boxes, and switch boxes connected to electrical equipment, forming a three-tiered distribution. The complete set of products can form a complete three-level protection system for construction electricity, achieving the goal of one machine, one switch, and one protection, which is very suitable for various standard engineering applications. Note: The three-level power distribution is mainly to ensure that each power-consuming device has electricity available; each power-consuming device can be used. After stepping down the voltage through the transformer's low-voltage side (0. From the transformer's low-voltage side (0. 4kV), power is distributed to a main distribution panel.