The control cabinet is the switching equipment and auxiliary equipment, measuring instruments and protection equipment assembled in a closed or semi closed metal cabinet or screen web according to the requirements of electrical wiring, the layout should be the normal operation of the power system to meet the requirements, easy maintenance, do not endanger personal safety and peripheral equipment. Normal operation can be manually or automatically switched on or off circuit. Failure or abnormal operation with the help of electrical equipment to cut off the circuit or alarm. The measuring instrument can display all kinds of parameters in the operation, and can also adjust some electrical parameters, which can be used to indicate the deviation from the normal working state. Commonly used in the hair, distribution, substation.