How do I wire a plug and change a fuse?

Which wire goes where, the correct fuse rating for the appliance, and when to replace the lead instead.

Difficulty: beginner
Time: 20 min
Read: 3 min
Safety: warning

Short answer

Brown to the live terminal on the right, blue to neutral on the left, green and yellow to earth at the top. Use a 3A fuse for appliances up to about 700W and 13A for anything above, unless the appliance states otherwise.

Rewireable plugs are less common than they were, but changing a fuse is still a routine job and knowing the wiring is genuinely useful. The two things that matter are getting the wires in the right terminals and using the right fuse.

Safety

Always unplug the appliance before working on the plug. Use the correct fuse rating for the appliance — fitting a higher-rated fuse removes the protection and is a fire risk. If you are not confident, a replacement moulded lead is inexpensive and requires no wiring.

What you'll need

Screwdriver
Correct fuse
Wire strippers (optional)

Step by step

Unplug the appliance before doing anything.Not switched off — unplugged. This is not negotiable.
For a fuse change, open the fuse compartment.Usually a small cover on the plug face, or under the plug's back cover. Ease the old fuse out and press the new one in.
Use the correct fuse rating.3A for appliances up to about 700W — lamps, radios, chargers. 13A for higher power — kettles, heaters, irons. Check the appliance rating plate if unsure.
Never fit a higher-rated fuse to stop it blowing.The fuse protects the flex. A higher rating means the cable can overheat before the fuse blows, which is a fire risk.
For rewiring, remember the terminal positions.Blue to neutral on the left, brown to live on the right where the fuse is, green and yellow to earth at the top. Blue and brown, left and right — bLue is Left.
Strip the right amount of insulation.Enough that no bare conductor shows outside the terminal, and no insulation is trapped inside it. Around 5mm for the terminals.
Make the earth wire slightly longer than the others.So that if the cable is pulled, live and neutral disconnect before the earth does. It is a deliberate safety design.
Secure the cable grip firmly over the outer sheath.It must clamp the outer sheath, not the individual cores. This is what takes any strain off the terminals.

Tips

If a fuse blows repeatedly, the appliance has a fault. Replacing the fuse over and over is not a fix and is not safe.
Moulded plugs cannot be rewired. If the plug or flex is damaged, replace the whole lead — they are inexpensive for most appliances.
Keep a few 3A and 13A fuses in the house. Discovering you have none at the moment something stops working is annoying.

Common mistakes

Fitting a 13A fuse to something that needs 3A — The fuse protects the flex, not just the appliance. An over-rated fuse lets the cable overheat before it blows.
Clamping the cable grip on the individual cores — It must grip the outer sheath. Otherwise any pull on the cable goes straight to the terminals and can pull a wire loose.
Replacing a repeatedly blowing fuse — It is telling you there is a fault in the appliance. Keeping it running is a genuine hazard.

Questions people ask

Which wire goes where in a plug?

Brown to live on the right, blue to neutral on the left, green and yellow to earth at the top. The memory aid is bLue to Left, bRown to Right.

What fuse do I need for my appliance?

3A for anything up to about 700W such as lamps and chargers, and 13A for higher-power appliances like kettles and heaters. The appliance rating plate gives the wattage.