Structural three hole socket: "Left zero and right fire above ground" (the ground wire is generally connected to a metal plate buried underground), as shown in the figure "Three wire plug and socket structure". Three wire plug: Electrical appliances with metal shells are basically three wire plugs, corresponding to three hole sockets. The function of grounding: The middle plug of the three wire plug is connected to the metal shell of the electrical appliance. When inserted into the three hole socket, it connects the metal shell to the ground&Nbsp; When installing the three wire plug correctly, it can be connected as shown in the diagram. Firmly connect the power cord to the plug. When wiring, it is important to distinguish which wire (which color) is the phase wire (live wire), which wire is the neutral wire (zero wire), and which wire is the ground wire. The International Electrotechnical Commission stipulates that the yellow green wire is the protective grounding wire (some Japanese and Western European products use a single green wire as the protective grounding wire). Use white wire as the neutral line (zero line), and red wire as the phase line&Nbsp; Three wire sockets refer to 220V power sockets for household appliances. The internal wiring method should be correctly connected according to international and national standards, which is commonly referred to as "left zero, right fire, and middle ground". If the internal wiring of the three-wire socket is incorrect (which may occur during decoration or informal electrician installation), users may not be able to work properly when plugging in electrical equipment, and in severe cases, it may cause the electrical casing to be electrified and cause a risk of electric shock&Nbsp; Not many people pay enough attention to the grounding wire of household appliances in the two wire plug. For ease of use, only connect the electrical equipment to the power supply, or break off the end of the power plug with a grounding symbol, and then plug it into the two hole socket. The shell or power plug of household appliances such as washing machines, electric heaters, refrigerators, and air conditioners are marked with a grounding symbol, which tells people that the electrical equipment should be grounded. The danger of not operating according to requirements is very high! Because the grounding wire is usually connected to the casing of electrical equipment, when these appliances leak electricity, the majority of the leakage current flows to the ground through this wire. If a person accidentally touches the shell of an electrical device and there is a grounding wire, only a small amount of current flows into the human body, which serves to protect the human body. If there is no grounding wire, it will be very dangerous to the human body&Nbsp; Glossary of Entries