how to identify two pin plug or three pin plug ?
Plug and three-pin plug the power cord plugs into two feet, two feet is the two core plugs, three feet is the three core plug, so what is the difference between the two plugs?
Two pin plug left foot to the zero line, his right foot after wire line (phase), constitutes the single-phase power supply circuit, electric equipment could work. These electrical appliances such as electric light, TV, etc., no metal shell, people not to touch the internal circuit, there is no risk of electric shock, as long as there are two wire is enough.
Three pin plug on top of the two foot by one foot (ground), constitute a triangle. The power cord plug of ground wire metal skin appliances, socket ground connection of the earth, make electrical enclosure and connected to the earth in a state of zero potential, people touch the metal parts, or damp parts will not get an electric shock. For the metal case or exposed metal, can be in contact with the water, or high power prone to leakage of electric equipment, such as refrigerators, water dispensers, washing machines, computers, smoke lampblack machine, rice cooker, etc., have to use three pin plug sockets, in order to ensure the safety of the people.
There is also a kind of using three-phase electric appliances, need three phase line to form a complete power supply circuit, so need three pin plug or four feet (one foot grounding) plug.
All kinds of power cord plug socket countries have mandatory standards and norms, such as GB/T11918 and GB/T11919, etc.
Last : D01