How to check and change an electrical plug

If an electrical appliance suddenly stops working, it may be that the fuse in the plug has blown.  If it happens repeatedly, have the appliance checked for faults by a qualified electrician.  NEVER be tempted to replace the fuse with one of a higher rating than is indicated on the manufacturer's instruction, in the hope that it will last longer, as it may damage the electrical circuit of the appliance, and your household wiring.

Replacing fuses in plugs:

1. Remove the plug cover, by unscrewing the large screw in the centre of the plug.  Note:  some more modern appliances now have factory sealed plugs, but the fuse is still accessible though a small removable flap. 
2. Pull out the cartridge fuse, and replace it with a new one of the correct rating.  Check that all wires are securely attached to all terminals.
3. Refit the cover, but make sure that you haven't trapped any of the cables when you are tightening the cover screw.

Fuse ratings:

1. Replace with the appropriate fuse for the appliance, checking the manufacturer's instructions if in doubt.  The smaller the fuse rating, the less power is consumed by the appliance.  For example, a table light will usually have a ‘3 Amp' fuse, whereas a kettle is likely to need a 13A Amp fuse. 

Trade tip: Plug fuses are marked BS1361.  Fuses box fuses are marked BS1362

You may need to change a plug because it has broken, or because you are attaching a new lead, or you may have simply opened it up to check that all the wires are securely attached.  In every case you must be sure that the plug is wired correctly.

Trade tip: If any wires have been pulled out of the terminals a way to remember which cable goes into which terminal is that the first two letters of the live cable (usually brown) i.e. BR, should be inserted into the Bottom Right terminal point, and the neutral wire (usually blue) i.e. BL should be inserted into the Bottom Left terminal, and the Earth cable, usually (usually green and yellow) connects to the top terminal.  In older wiring, the Red is the live cable, and the neutral cable is black. 

Changing a plug

1. Remove the cover and the fuse.  Loosen the flex-retaining screws at the base of the plug, and remove the flex.  Insert the flex under the new anchor strip in the new plug, and tighten the screws to secure.
2. Attach the wires to the appropriate terminals (see above), and tighten the screws firmly.  Note: the wire may need to be stripped back so that only the copper wire is touching the terminal.  Make sure you do not strip back too much as this could be dangerous if bare wires are exposed when you put the plug back together. 
3. Replace the fuse, and screw on the plug cover.

Connecting a 2-wire flex:

1. If your flex has only two wires, connect the wires as follows:  ‘L' for live and ‘N' for neutral as there is no earth wires to connect to the ‘E' terminal.  Only items that are double insulated (such as a power drill or some standard lamps) do not require an earth wire.  Check the manufacturer's instruction if in doubt, or call a qualified electrician.

It is good practice to occasionally check the flex itself, particularly if you have pets that may have chewed the wire, as this can be very dangerous for you and your pet.  If your electrical appliance continues to fail, it may be that there is a fault with the item, or a more difficult fault.  If you are worried about this, contact a qualified electrician or your item's manufacturer for more help.

Paul Carr is a qualified and very experienced Part P registered electrician, with over 15 years in the trade.  He is based at Hazel Grove, Stockport, Cheshire.  Visit his website at http://www.paulcarrelectrical.co.uk