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Wonders of Physics

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Double Insulation



Double Insulation

Why some electrical appliances do not need earth wire or they only have 2 pins (live and neutral)? For some 3 pins plug, the earth pin is actually plastic (that means no earth wire). Why?


Why make the earth pin with plastic since there is no earth wire?
Having the plastic earth pin is to provide convenience for user to plug in the 3-pins. Without the earth pin the plug wouldn’t go into the socket. The earth pin is needed to open a cover inside the socket that stops people from touching the live parts.

(Thanks Bob Barrett for the suggestion to improve the explanation)