1、 The power distribution system at the construction site shall be equipped with indoor general distribution panel and distribution box or outdoor general distribution box and distribution box for hierarchical power supply, and the capacity of distribution devices at all levels shall match the actual load. Power and lighting shall be set separately.

2、 The manufacture and installation of distribution box and switch box shall meet the following requirements:

(1) The distribution box shall be made of iron plate or other fire-proof insulating materials to achieve ventilation, heat dissipation, rain proof and fire-proof.

(2) All kinds of electrical appliances in the box shall be installed on metal or other insulating boards (non wooden boards) and fastened in the box. The metal base plate shall be electrically connected with the box body.

(3) Normally, the metal shell and base of the non electrified box shall be connected to neutral (ground), and shall be connected through special terminals, and shall be set separately with the protective zero line terminal block. All electrical connecting wires shall be insulated wires with reliable joints and shall not be exposed.

(4) Rubber insulated cables shall be used for the incoming and outgoing lines, and the incoming and outgoing ports shall be set at the lower end face of the box body, with protective rings added. The incoming and outgoing lines shall be provided with waterproof bends and shall not bear external forces.

3、 The rated value and action setting value of the main distribution box shall be compatible with the rated value and action setting value of the branch switch. The main automatic switch, leakage protector and shunt automatic switch shall be installed

4、 All kinds of electrical components and leakage protectors used in distribution boxes at all levels shall meet the quality requirements of national standards.

5、 The leakage protectors in distribution boxes at all levels shall be arranged reasonably to play the role of grading and subsection protection.