When the distribution box is only a lighting box or small power equipment, when the incoming line is less than 10 square, and the number of switches is less than 20, the width of the switch is added and 20mm on each side is the width of the electrical box, and the height is the height of the switch plus 40mm. The depth is the maximum depth of the switch plus 10mm.

Distribution box installation requirements:

The power distribution system on the construction site should be equipped with indoor general power distribution panels and distribution boxes or outdoor general power distribution boxes and distribution boxes for grading power supply, and the capacity of all levels of power distribution devices should match the skin. Power and lighting should be set separately.

The production and installation of distribution boxes and switch boxes shall meet the following requirements:

1) The distribution box is made of iron plate or other fireproof insulating materials to achieve ventilation, heat dissipation, rain protection and fire

2) Various electrical appliances in the distribution box should be installed on metal or other insulating boards (not wood boards) and fastened in the box. The metal bottom plate should be electrically connected to the box body

3) The metal shell of the normal non-live box body, the base must be grounded, and connected through a dedicated terminal, and is separated from the protective neutral wiring terminal board. Insulated wires should be used for all electrical connection wires, and the joints should be reliable and not exposed

4) Rubber insulated cables must be used for incoming and outgoing wires, and the inlet and outlet ports should be located on the lower end of the box with a protective ring. The incoming and outgoing cables should be waterproofed and must not bear external forces.

The electrical rated value and action setting value of the main distribution box should be compatible with the rated value and action setting value of the shunt switch appliance. And install the main automatic switch, the leakage protector and the branch automatic switch.

Various electrical components and leakage protectors used in distribution boxes at all levels should meet quality requirements.

The leakage protectors in the distribution boxes at all levels should be arranged reasonably to play the role of graded and segmented protection.

The leakage protector should be used in strict accordance with the product manual, and the test should be performed regularly and the operation record should be kept. Products that have been idle for a long time and used continuously for more than one month should be inspected and tested, and can be used only after they are qualified.