A mains electricity cable contains two or three inner wires. Each has a core of copper, because copper is a good conductor of electricity. The outer layers are flexible plastic, because plastic is a good electrical insulator. The inner wires are colour coded and have different functions:
|Brown||Live||Is held at a voltage of 230 V and provides the current|
|Blue||Neutral||Completes the circuit|
|Green and yellow stripes||Earth||A safety wire to stop the appliance becoming live|
An earthed conductor cannot become live.
In a plug, the blue neutral wire goes to the left, the brown live wire to the right and the green and yellow striped earth wire to the top. The fuse fits next to the live wire.
The diagram shows the key features of a three-pin mains plug:
There is an easy way to remember where to connect each wire. Take the second letters of the words blue, brown and striped. This reminds you that when you look into a plug from above: