Evan's Space

Wonders of Physics


2 Comments

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?

Double_insulation_01Double_insulation_02Double_insulation_03

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)

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