Plugs
The electricity coming into your home is called mains electricity.
Mains voltage in Northern Ireland is 230 V.
A plug connects a device to the mains electricity supply.
The cable between the device and the three-pin plug contains three copper wires that are coated with plastic.
- copper wires are good An electrical conductor is a material which allows an electrical current to pass through it easily. It has a low resistance. ;
- plastic is a good An electrical insulator is a material which does not allow an electrical current to pass through it easily. It has a very high resistance..
Each part of the plug has a function.
| Features of a plug | Function |
| Outer insulation | All three wires in the cable are bundled together and there is extra plastic insulation wrapped round them all for safety. |
| Cable grip | This holds the cable tightly in place so that wires do not become loose. |
| Live wire | Copper wire coated with brown plastic along which the current enters the device. |
| Fuse | A glass or ceramic canister containing a thin wire that melts if the current gets too high. |
| Neutral wire | Copper wire coated with blue plastic that also connects to the cable in the wall and completes the circuit. |
| Earth wire | Copper wire coated in striped yellow and green plastic that provides a path for current to flow from the case of the device to the ground if there is a fault. |
| Features of a plug | Outer insulation |
|---|---|
| Function | All three wires in the cable are bundled together and there is extra plastic insulation wrapped round them all for safety. |
| Features of a plug | Cable grip |
|---|---|
| Function | This holds the cable tightly in place so that wires do not become loose. |
| Features of a plug | Live wire |
|---|---|
| Function | Copper wire coated with brown plastic along which the current enters the device. |
| Features of a plug | Fuse |
|---|---|
| Function | A glass or ceramic canister containing a thin wire that melts if the current gets too high. |
| Features of a plug | Neutral wire |
|---|---|
| Function | Copper wire coated with blue plastic that also connects to the cable in the wall and completes the circuit. |
| Features of a plug | Earth wire |
|---|---|
| Function | Copper wire coated in striped yellow and green plastic that provides a path for current to flow from the case of the device to the ground if there is a fault. |
One way of remembering the position of the wires is:
| Colour | Position |
| BLue | Bottom Left |
| BRown | Bottom Right |
| Colour | BLue |
|---|---|
| Position | Bottom Left |
| Colour | BRown |
|---|---|
| Position | Bottom Right |