Due to the improper selection of AC contactor capacity in manufacturing, the installation of AC contactors with the same capacity for different outgoing circuits without considering the imbalance of three-phase load, and the failure to improve the current level selection of some outgoing contactors based on the normal selection of models, resulting in the burnout of AC contactors during operation in high temperature seasons in summer Situation.

The distribution box is to assemble the switchgear, measuring instruments, protective appliances and auxiliary equipment in the enclosed or semi enclosed metal cabinet or on the screen according to the electrical wiring requirements to form a low-voltage distribution device.

In normal operation, the circuit can be turned on or off by means of manual or automatic switch. In case of fault or abnormal operation, cut off the circuit or give an alarm with the help of the protection appliance.

With the help of measuring instruments, various parameters in operation can be displayed, and some electrical parameters can be adjusted to prompt or send signals for deviation from normal working conditions.

It is commonly used in each power generation, distribution and substation.