Voltage switchgear and transformer switchgear cabinet selection problem is an electrical device, outside the first master switch into the cabinet, and then enter the sub-control switch, each branch according to need. Such as instrumentation, automation, motor magnetic switch, all kinds of exchanges and contacts, etc., Kaifeng low voltage, and some also set up the high-pressure chamber and the low-voltage switchgear room with high-voltage bus, such as power plants, and some also have a protection of major equipment .1 low cycle load shedding, high voltage switchgear vacuum circuit breaker inside the car after closing the test position, the car can not enter the work breaker position. (To prevent closing with load) 2, High Voltage Switchgear ground knife within close position, the car can not enter the circuit breaker closing. (With a ground wire to prevent closing) 3, high voltage switchgear vacuum circuit breaker in the closing work within and panel back door and door lock with a mechanical knife on the ground. (To prevent mistakenly charged interval) .4, vacuum circuit breakers high voltage switchgear at work within the closing, ground knife can not be put together. (Antistatic articulated ground) 5, the vacuum circuit breaker at work within high voltage switchgear closing operation, you can not quit working position car breaker. (To prevent negative Hera Knife) High Voltage Switchgear schematic diagram to see how the subject (of programs) is more convenient, Gongyi low voltage switch, you can use the schematic wiring diagram and terminal diagram and control, a one loop Look, a general schematic first AC circuit (such as current and voltage loop, current transformers, current protection, metering, etc.), then the DC circuit (control, signal circuit), the last tank circuit, lighting heating! Figure can be left to right, the first following, low voltage switch, one contact and one coil left off, we can see loop number (Menu distinction), such as current is A, B, C, Qingfeng high and low switch, N421, positive supply 1, 2, etc. negative power supply, low voltage switch easily Qingfeng, learning Connaught Electrical and Mechanical (online consultation), low voltage is provided by habit Connaught Mechanical and Electrical Equipment Co., Ltd., Henan. Henan Xi Connaught Electrical Equipment Co. (www.hnxinuo.com) is Zhengzhou, electronics, electrical products processing leader, over the years, the company is implementing the scientific management, innovation and development, the principle of honesty and trustworthiness, and satisfy customer needs. In practice Connaught Electrical and Mechanical leadership with the staff warmly welcome all inquiries negotiations to create learning Connaught Electrical and Mechanical better future.