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Basic knowledge of electric power drag ppt courseware
Most of the control appliances used in the production machinery of electric drag basic knowledge belong to low-voltage appliances. It refers to electrical appliances used to connect or disconnect circuits and control, regulate and protect electrical equipment when the voltage is below 500V. Electrical appliances can be divided into the following two categories according to the nature of their actions: (1) Non-automatic appliances: These appliances do not have a power mechanism and rely on human power or other external forces to connect or disconnect circuits, such as knife switches and transfer switches. (2) Automatic electrical appliances: These electrical appliances have power mechanisms such as electromagnets, which automatically operate in accordance with changes in instructions, signals or parameters, and make the working circuit switch on and off, such as contactors and automatic switches.