Primary distribution box

It refers to the main distribution box. Generally located in the power distribution room.

The first level cabinet adopts the bottom inlet and outlet cable, the front door is open, the main bus cable is connected by copper bar, the contact is good, and the internal measurement system is carried. Safe and beautiful, rain box top suitable for field work.

Secondary distribution box

That is, the distribution box, also called the sub-box, is generally responsible for a power supply area.

The secondary box is designed with internal and external doors, and the appearance is sprayed with plastic. Safe and beautiful, rain box top suitable for field work.

Three-stage distribution box

It's a switch box. It can only handle one device. The so-called one machine, one gate, one box, one leak; It's for the switch box.

1. Configure the power distribution box

The configuration in the box, it is recommended to look at the "Construction site temporary electricity specifications", which is very clear about the configuration requirements inside the distribution box at all levels. Just a few words here;

Level 1 requirements configuration: total circuit: total isolation + total circuit breaker or total fuse; Branch: Branch isolation + branch leakage protection switch.

Secondary requirements: Total circuit: total isolation + total circuit fuse or circuit breaker; Shunt: Shunt isolation + shunt fuse or circuit breaker.

Three requirements configuration: isolation + leakage protector. Among them, the leakage protection switch in the primary distribution, the product of the operating current and the operating time is not more than 30 milliampere seconds. The operating current of the leakage protection switch in the three-level distribution is not more than 30 MA, and the operating time is not more than 0.1 seconds.

The surge protector

General configuration requirements:

The first stage: generally installed in the low-voltage total line switch. Withstand lightning strikes or induced lightning strikes of large current, can divert a large number of surge current to the earth. The lightning current is not less than 60KA (three-wire voltage switch type).

Second level: installed in the branch distribution equipment of important or sensitive electrical equipment. Generally, 40KA (pressure limiting type) is selected.

Level 3: Installed in the internal power supply part of the electrical equipment. Generally choose 20KA or less (series type limited voltage type)