How to define primary distribution box and secondary distribution box in construction site

The main distribution box is the centralized point for controlling all power sources on the construction site and should be set near the power supply area. The main distribution box is the centralized point for controlling all power sources on the construction site and should be set near the power supply area.

The power supply is connected by the cable led from the low voltage side of the power transformer on the construction site, and the current transformer, active watt-hour meter, reactive watt-hour meter, ammeter, voltmeter, main switch and sub-switch are installed. The switches in the main distribution box shall be breaker switches (or leakage protection switches). Lead-in and lead-out wires should pass through the pipeline and have waterproof bends.

2. Secondary distribution box

Secondary distribution box, namely distribution box, also known as sub-box, is generally responsible for a power supply area.

Bus: bus isolation+bus fuse circuit breaker or circuit breaker; Shunt: shunt isolation+shunt fuse circuit breaker or circuit breaker.

Suitable for the construction of construction sites. Specially designed for the special situation of engineering construction site, in line with the relevant construction electricity standards of the Ministry of Construction. A complete set of products can form a complete three-level protection system for construction electricity, and achieve the purpose of one machine, one brake and one protection. The auxiliary box adopts the design of inner and outer doors, and the exterior is sprayed with plastic, which is safe and beautiful. The rain-proof box top is suitable for field work.

Extended data

Distribution box principle:

Distribution box is a low-voltage distribution box that assembles switchgear, measuring instruments, protective appliances and auxiliary equipment in a closed or semi-closed metal cabinet or screen according to the requirements of electrical wiring.

During normal operation, the circuit can be turned on or off by manual or automatic switch. When there is a fault or abnormal operation, cut off the circuit or give an alarm with the help of the protection device. Through measuring instruments, various parameters in operation can be displayed, and some electrical parameters can be adjusted to prompt or signal deviations from normal working conditions.

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