DIY Tips: #2 Change a fuse

Fuses are a deliberate weak link in a circuit. The strands of wire used in fuses are thinner than those used in the rest of the wiring circuit. When a fault occurs in your wiring or a piece of equipment, either through overloading, through a short or ‘earthing out’, there will be a significant increase in power through the cables. This causes the thinner fuse wire to rapidly heat and melt, quickly breaks the circuit, switching off the power.

The limit at which a fuse ‘blows’ is determined by the thickness of the wire running through it. Different thickness fuse wires blow at different levels of power. Exceeding the maximum rated for that fuse wire will cause the wire to break. Modern installations make use of ‘circuit breakers’ instead of the old style fuse wires. These devices will detect an increase in the current and automatically switch off the power. The advantage of these devices is that they can simply be reset by pressing a button.

Incorrect value fuses are a hazard, not only to the equipment they are protecting but also to your health. This socket will have to be replaced and the wiring checked – the equipment which was plugged into it is most probably no good now unless it had an extra internal protection fuse which may have saved it.

Handy Fuse Chart for 3 pin plugs:

Power Consumption				Fuse
<230W (e.g. bedside lamp)				1 Amp
231w – 690w (e.g. stereo)				3 Amp
691 – 1150w (e.g. Vacuum)				5 Amp
>1151w (e.g. heater, bread maker)				13 Amp

It is very sensible to keep a selection of fuses somewhere handy – somewhere you can find in the dark is good. A packet of common fuses doesn't cost much and one day you'll be glad you got them – I promise. Oh and a torch – a working torch.

Now, to replace the fuse in a plug – Loosen the centre screw from the pin side of the plug (do not loosen the two (if there are any) close to the point where the cable goes into the plug). Remove the plug back to expose the wire connections and the fuse.

Take a small screwdriver and lever out the fuse from its grips – if a terminal comes up with the fuse, just push it back into place. Always replace fuses with the correct rating/value fuse and certainly don't ever be tempted to use a higher rated fuse to “stop the thing keep blowing”. If the fuse does keep blowing, this is telling you there is something wrong – either with the equipment or with the wiring – you really must get them checked. Before you screw the top back onto the plug just check the terminals holding the wires are correct to the diagram above and there are no stray strands of wire and that the terminal screws are tight. Once the back is on – plug it back in, turn the kettle on, have a cuppa and a custard cream – job well done. Oh one last thing on plug fuses – the plug will probably say on it “13A” this is what the plug is rated to – not what fuse should go in it – always use the correct rating fuse for your equipment.

Sadly I have run out of space to cover fusebox / consumer unit fuses this week.

Next week we shall repair a blown fuse in a fusebox.

Keep safe.

Dave

DIY Tips: #1 A bit about Electricity

DIY Dave

Each week, I will bring you useful, handy and important DiY tips and tricks to help you save money in simple, clear and easy to understand step-by-step guides to the more simple tasks around your home. Some tasks around the home do need professional help – so, I will NOT be taking you up onto your roof or down into your drains, getting you to plaster a room or build an extension. However, in the weeks to come, we (you and I) will mend fuses, change light fittings, fill cracks in walls, paint and fix dripping taps and cold radiators and all sorts of other tasks, around our homes.

DIY Tips: #1 A bit about Electricity

Firstly: Electricity is big and grown-up and powerful. I don't want to have to tell you this again so take note: Electricity is powerful enough to injure you, or others, burn your house down or even kill you (or all four) so don't mess around with it. If you're not sure - do contact an electrician. On the other hand though, the movement of electrons is what makes our world tick – so, it is a nice idea to get to know as much about it as you can. If you wish to feel a few of these electrons in action – get a type PP3 9volt battery (or get a teenager to do this if you have one at home, it will wake them up and make them feel useful) – oh, if you try this on anyone younger, or on your granny, it is probably a crime, SO DON'T, JUST DON'T.

Now, simply touch the terminals on the top of the battery, both at the same time, with your tongue … feel that tingle? What you just felt was comparatively few electrons moving between the terminals via your tongue - only 9 volts – household electrics are 240volts (which is 26 times greater or 2600% if you wish to be mathematically pedantic) so;

Don't even think about touching household electricity wiring with any part of yours or anyone else’s body unless you are sure the power is switched off AND isolated AND the fuse is removed AND in your pocket.

Oh and for any numpty thinking “I wonder what jolt I'd get from licking a car battery” DON'T DO IT – LICKING A CAR BATTERY TERMINALS WILL POSSIBLY BURN YOUR TONGUE OFF AND SET YOUR EAR HAIR ALIGHT and besides, it is dirty (and don't lick any other part of your car either).

Domestic fuseboxes

These days there are several different types of fuse boxes (consumer units) in domestic properties. These are some examples:

If your fusebox looks like any of the five above you should seriously consider getting an electrician to quote for a new Consumer Unit – these are all outdated, could be dangerous and could be fire hazards.

This is a more modern example of fusebox/consumer unit with RCD trips and up-to-date circuit protection.

Next week we shall replace a fuse in a plug and repair a blown fuse in a fusebox.

Just a bit to start

I have been 'doing it myself' through necessity in all my homes, for many years. When needed I call in the professionals, but when the task is small and not difficult – I do it myself. I hope to help readers, confidently and safely tackling these small, easily managed DiY tasks. I shall offer hints and tips along the way, and as my old Dad used to say “measure twice, cut once”, then, as I got older, “Do it Yourself, Dave”.

Planned DiY Tasks:

A bit about Electricity

Replacing a fuse

Mending a fuse in the fusebox

Replacing a light fitting

Repairing a dripping tap

Mending drooping kitchen cupboard doors

Mending sagging kitchen drawers

Fitting a new toilet seat

Refitting internal door hinges

Repairing a damaged internal door

Replacing a light switch

Painting indoors

Painting outdoors

Replace a plug

Telephone extension

Fitting Hanging Baskets

Fitting Shelves

Wall papering

Fitting bathroom tiles

This list is not exhaustive and readers can submit suggestions for future tasks.