The control cabinet is to assemble the switchgear, measuring instrument, protective appliance and auxiliary equipment in the closed or semi-closed metal cabinet or on the screen according to the electrical wiring requirements. The arrangement should meet the requirements of the normal operation of the power system, which is convenient for maintenance and does not endanger the person. And the safety of the surrounding equipment. The circuit can be switched on or off with a manual or automatic switch during normal operation. In the event of malfunction or abnormal operation, the circuit or alarm is cut off by means of a protective device. The measuring instrument can display various parameters during operation, and can also adjust some electrical parameters to prompt or signal the deviation from the normal working state. Commonly used in various hair, distribution, and substation.