Wiring a plug
These days you don't often have to know how to wire a plug, as most appliances come with a fitted plug. However, if you encounter an older item you may need to know how to wire a plug.
The face of the plug has three screws - the one in the centre holds the plug together. The two lower ones hold the cord grip in place. Undo the centre screw to open the plug.
Inside you will find three terminals:
- Earth: This is where the green and yellow wire goes - however, double insulated appliances do not have an earth wire.
- Live: The brown wire goes to the live terminal, and is also connected to the fuse, which is on the right of the plug.
- Neutral: The blue wire connects to the neutral terminal on the left of the plug.
To fit a wire to the plug, you first need to cut the leads to the right length. Do this as follows:
- Hold the wire up to the plug with the end of the wire reaching the furthest terminal on the plug (the earth terminal).
- Mark a line inside the cord grip - it is essential that the cord grip grips the outer insulation of the wire, not the single wires.
- Using a sharp knife, carefully score the surface of the outer insulation - be sure not to cut the inner insulation. If you should cut the inner insulation, you will need to cut the end of the wire off at that point and start over.
- Once you have scored the outer insulation, bend it back and forth a few times to get a clean break in the outer insulation. Once if has split all the way through, grip the end of the outer insulation with some pliers and pull the broken piece off. This will expose the inner wires.
- You will find at this point that the inner wires need trimming - carefully mark them, then cut them to the correct length.
- Next, you need to remove sufficient insulation from the individual wires to fit them into the terminals. You can either cut them with a sharp knife, as you did with the outer insulation, or nip them gently with wire cutters. It works best if you remove about 10mm of insulation. You can then twist the strands of the wire together and fold the bare wire in half before inserting it into the terminal - this provides the most secure grip.
Once your wires are prepared, you have to thread the whole wire through the cord grip, insert each individual wire into the correct terminal, and tighten the terminal screws and the cord grip screw. Finally, check that the correct fuse is in place, then close and refasten the top of the plug.