Most of the electricity used in life is a single-phase 220 volt power supply. There are usually two wires in the house. One is a fire wire and the other is a zero wire. Although the neutral wire is not charged, but there is no neutral wire, the current shape cannot be operated without a loop; We have a zero line, why use electric appliances such as refrigerators, electric fans, washing machines, etc., but also the grounding wire?
Electricity is one of the greatest inventions of mankind, and now all aspects of our lives are indispensable. But at the same time, electricity can't be seen or touched. In case of electric shock, the current is small, but if the current is too large, earth wire it will endanger people's lives. The "electric tiger" copper clad steel will eat people. In order to ensure personal safety, people have added a third line for the electrical appliances - the protective ground wire, referred to as the ground wire. One end of the ground wire is connected to the outer casing of the electric appliance, and one end is connected to the grounding pole buried in the ground.
In this way, when the insulation inside the appliance is damaged, the electricity flows from the ground to the ground, and people do not have to worry about getting an electric shock. But some people may say: "I have seen a lot of electrical appliances, but I have never seen any wires connected to the ground?" The grounding wire is not connected to a wire from each electrical appliance, and then buried underground. You see, most of the electrical jacks have three feet, one of which can be grounded. This ground wire is pre-installed. Maybe a building has only one ground wire. Other electrical appliances are connected to this ground wire. Connected. At the same time, the grounding device is provided on the outer casing of the general electrical appliance. When using the appliance, just plug the three-pin plug and it is grounded. So, you don't think the appliance seems to be grounded. In fact, it has already been connected. Otherwise, can you use it so safely?