The distribution board is to assemble the switchgear, measuring instruments, protective appliances and auxiliary equipment in a closed or semi closed metal cabinet or panel according to the electrical wiring requirements to form a low-voltage distribution device. During normal operation, the circuit can be connected or disconnected with the help of manual or automatic switch. In case of fault or abnormal operation, cut off the circuit or alarm with the help of protective appliances. The measuring instrument can display various parameters in operation, adjust some electrical parameters, and prompt or send signals for deviation from the normal working state. It is commonly used in various power generation, distribution and substation.