In China's economic and social development and the daily life of the people, the use of electromagnetic energy is becoming more and more common. Completion of industrial production, agriculture and animal husbandry, national defense security and scientific and technological progress of the intelligent, it is even more inseparable from the electrification. In order to better safety. Reliable application of electromagnetic energy, power supply circuit must be equipped with a variety of electrical equipment. This kind of electrical equipment is commonly known as electrical appliances, which are divided into high-voltage electrical appliances and low-voltage electrical appliances according to the working standard voltage and M network movie categories. Customarily, electrical appliances in power circuits above 5kV are called high voltage appliances. Bottom-voltage appliances are appliances used in power circuits with AC 50Hz or 60Hz, rated currents of 1200V or below, or DC 1500V or below. It plays in the power supply system maintenance, manipulation, adjustment, transformation and conduction effect, the type of bottom-voltage appliances are diverse, according to its structure and the main purpose of the manipulation of different objectives, can have different categorization methods.

(1) according to the main purpose and manipulate the target according to the main purpose and manipulate the target is not the same, the bottom-voltage electrical appliances can be divided into power distribution equipment electrical appliances and manipulate the electrical appliances. Used in the bottom-voltage power grid distribution equipment appliances, including knife gate, switching switch, air circuit breaker and circuit breaker and so on. The key technical standards for power distribution equipment and electrical appliances are strong current-breaking capability, good overcurrent protection, correct posture when common faults occur in the system software, reliability in work, sufficient heat resistance and dynamic reliability.

Manipulation of the electrical key for power traction and fully automatic automatic control systems. The key has AC contactor, driver, main order electric appliance, all kinds of maneuvering relays and so on. The key technical standards for the manipulation appliances are moderate change-over capability, high frequency of actual operation, and long service life of electric and mechanical equipment. Manipulators used in electric power traction and fully automatic control systems include AC contactors, actuators, main command appliances, and various types of manipulation relays. The key technical standards for the manipulation of electrical appliances is the actual operation frequency, long service life and its corresponding transformation ability.

DC circuit breaker DC power network power circuit, DC circuit breaker with load long delayed maintenance, short-circuit fault instantaneous maintenance role, DC circuit breaker is used to distribute electromagnetic energy and maintenance routes and power supply equipment from loads, short-circuit faults and other common faults.

DC circuit breaker can also be used for solar power station system software, can quickly open the DC power distribution system of common faults in the flow of electricity, maintenance of solar power station system software in the key components - solar power control module from the DC side of the reverse direction of the flow of electricity and inverter power supply caused by common faults in the communication side of the feedback flow of electricity, DC circuit breaker to ensure that the photovoltaic power generation system software of power generation. The DC circuit breaker ensures the reliable operation of the PV power generation system software. The actual operation of DC circuit breaker organization With rapid closing and rapid opening and closing role, compact structure, small size, easy to use.

(2) According to the posture method Receiving posture method, low le electrical appliances can be divided into full-automatic appliances and manual appliances. Full-automatic electrical appliances are the electrical appliances that carry out the posture of accessing, opening and closing, running, reversing direction and terminating. It is relying on its own main parameters created, rather than by human power immediately actual operation. Common fully automatic conversion appliances are control switches and AC contactors.