Everything has to be 13 Amp??!!

[big-all]

i consider my choice off using as small a fuse as possible as the safest option

That's because you are thinking that the fuse is there to protect the appliance.
It is not. It is there to protect the cable.

The manufacturer will fit the appropriate cable and plug/fuse for the appliance - e.g. 13A fuse, 16A cable (talking about household appliances with fitted flex and moulded plugs).
Should the appliance be less than 690W then because of cost saving the manufacturer will use smaller cable - e.g. 3A fuse, 6A cable.
Here 5A would do equally well but only 3A and 13A are fitted.

As said, should the appliance need more protection then an internal small fuse will be included.

i have never ever noted any damage or overheating smells whilst running any item or changing a blown fuse

Well, you wouldn't - the fuse blew.

in other words everything worked and appeared normal

Apart from the fuse blowing - because it was too small (if that's what you mean).

can anybody tell me what i am doing is other than sensible and safe and why

It is unnecessary.
Had you used 13A fuse you may never have had to change one.

That is unless you have had fixed loads causing overloads.

thanks very much for answering
i suppose the main point i am asking is it logical to triple the current before overloading by reducing the available fuse options or is the likely flowing current unlikly to cause extra danger or dammage

 

[EFLImpudence]

You're still not accepting that the fuse is to protect the cable.

You are imagining saving the internal workings of an appliance in the event of a fault - but it is still a fault.
It won't get better because of a smaller fuse.

If the product were to be less of a danger or less damaged by a fault because of what you are suggesting then the manufacturer would fit an internal fuse which, when necessary, they do...

...or (because you are quoting a 4A load) an appropriate specialised fuse in the plug (5A) which they don't.

 

[big-all]

ok thanks for your answer i do realise its to protect the cable
we are going around in circles so will draw a few lessons and move on thank you

 

[sparkwright]

Is the fuse always there to protect the mains wiring and not the appliance?

Many appliances have rather small wiring within them like ovens.

A boiler will normally insist on a 3 amp fuse to protect it's circuit board.

Some fans insist on a 3 amp fuse. These often contain miniature wiring as well as circuit boards and the like.

 

[EFLImpudence]

Is the fuse always there to protect the mains wiring and not the appliance?

We were discussing fuses in (moulded) plugs (on a microwave) and why it is not necessary to fit a smaller one.

However, the manufacturer's of products not supplied with flex an plug could fuse their own products rather than tell us to fit one.

Many appliances have rather small wiring within them like ovens

I think you are contradicting yourself. Ovens will likely be on a 32A circuit.

Small items supplied with 3A fuse in the plug with 6A flex should/will be internally fused by the manufacturer if necessary.

A boiler will normally insist on a 3 amp fuse to protect it's circuit board.

Boilers are not supplied with flex and plug so manufacturer is stating necessary fusing because it has not been done by them
plus there are smaller fuses on the pcb.

Some fans insist on a 3 amp fuse. These often contain miniature wiring as well as circuit boards and the like.

Again, they are not supplied with flex and plug and again the manufacturer is telling us to do it because they have not.

The point of the thread being that whatever fuse is fitted (or demanded) there is no need to fit a smaller one just in case.



To repeat-

Is the fuse always there to protect the mains wiring and not the appliance?

It should be but sometimes the manufacturers rely on 134.1.1 to save themselves a few pence per item.