Mains Electricity

Question	Answer
What is the blue wire?	Neutral wire - attached to the left-hand pin
What is the brown wire?	Live wire - attached to the right-hand pin
What is the green/yellow wire?	Earth wire - attached to the top pin
Why must appliances with metal casing be earthed?	So that the current flows though the ground rather than the casing. It prevents the casing from becoming live.
Why does the earth cable touch the casing?	If the live wire comes into contact with the casing, the current has to flow back through the earth wire into the ground.
What does RCCB stand for?	Residual current circuit breaker
What is the purpose of an RCCB?	If the current is different through the live and neutral wires, it cuts off the circuit.
What does a fuse do?	If the current flowing through a circuit is too high, the fuse melts and breaks the circuit.
Which wire is connected to the fuse?	The live wire

Resource summary

	Created by Sarah Collinson over 10 years ago