Wiring a Plug

Most electrical appliances are connected to the mains using cable and a three-pin plug. The cable we use to connect appliances to a plug is called flex, this is because it is __________.

Most Flex is made up of 3 cores, each in its own colour coded insulation, all within an outer sheath.

Colour Code	Name of wire	Purpose
__________	__________	Delivers the energy from the power station Applies the voltage and so 'Pushes and pulls' the current in the circuit
__________	__________	Connected to earth back at the power station This is where the current is 'pulled from' and 'pushed to'
__________	__________	A safety feature that allows current to be 'dumped' to earth

The live terminal __________ between positive and negative potential with respect to the neutral terminal. The neutral terminal stays at a potential close to __________ with respect to earth. While the earth wire and fuse together __________ the appliance and the user.

		__________ Wire
		__________ Wire

Appliances with __________ cases are usually earthed. Appliances with __________ cases are said to be double insulated and so do not need an earth wire. Such appliances use a two-core cable in which there is only __________ and __________ conductors.

The appliance's flex is normally connected to the mains with a 13 amp square pin plug:

	____________________			____________________
					__________
	____________________
					__________
	__________

The plug contains 2 safety features of its own:

• __________
• __________

It is important that the earth wire is the longest of the 3 wires, so that if the wire is tugged out of the plug the earth wire is the last to be disconnected.