(1) The construction power distribution system should be equipped with a main distribution box, sub-distribution boxes, and switch boxes, and should be set up in a hierarchical manner according to the "main-sub-switch" sequence to form a "three-level power distribution" model.
(2) The installation locations of each distribution box and switch box in the construction power distribution system should be reasonable. The main distribution box should be located as close as possible to the transformer or external power source to facilitate power supply. Sub-distribution boxes should be installed in the central area where electrical equipment or loads are relatively concentrated to ensure that the three-phase load remains balanced. The location of the switch box should be as close as possible to the electrical equipment it controls, depending on the site conditions and working conditions.
(3) To ensure the balance of the three-phase load in the temporary power distribution system, the power supply and lighting supply at the construction site should form two separate power circuits, and the power distribution box and lighting distribution box should be set up separately.
(4) All electrical equipment at the construction site must have its own dedicated switch box.
(5) The enclosure and internal layout of each level of distribution box must comply with safety regulations. Switches should be labeled with their purpose, and the enclosures should be uniformly numbered. Power to unused distribution boxes should be disconnected and the doors locked. Fixed distribution boxes should be fenced off and have rain and impact protection measures.
(6) Difference between distribution boxes and distribution cabinets. According to GB/T20641-2006 "General Requirements for Empty Enclosures of Low-Voltage Switchgear and Controlgear Assemblies"