Plugs and Wires Flashcards
What is a Three-Core Cable and what wires does it have inside?
A three-core cable is a cable with 3 wires inside, and these wires are:
The Live Wire
The Neutral Wire
The Earth Wire
Each of the wires are made of copper, and coated in a layer of insulating plastic for safety.
What colour is the live wire?
Brown
What does the live wire do?
It provides the alternating potential difference of around 230V from the mains supply.
What colour is the neutral wire?
Blue
What does the neutral wire do?
It acts to complete the circuit by carrying away current. So, electricity flows into the device through the live wire, and flows out through the neutral wire, which has a potential difference of 0V.
What is the colour of the earth wire?
Striped green and yellow
What does the earth wire do?
The earth wire doesn’t normally carry a current, and has a potential difference of 0V. Its role is to stop the appliance casing from becoming live, which could happen if the live wire became loose and touched the casing.
This means, if we were to touch the casing, we would get an electric shock. To prevent this, the earth wire provides an alternative pathway for the current to flow away, so that any dangerous electricity will pass through the earth wire rather than passing through us.
Why is the electricity from the live wire able to pass through to the neutral/earth wire?
They both have potential differences of 0V, while the live wire is at 230V. It’s this difference in voltage that causes electricity to pass from one to the other.
