On 20/11/2016 12:51, wrote:
On Sunday, 20 November 2016 04:19:00 UTC, John Rumm wrote:
On 20/11/2016 02:28, tabbypurr wrote:
On Sunday, 20 November 2016 00:11:32 UTC, John Rumm wrote:
On 19/11/2016 20:13, tabbypurr wrote:
On Saturday, 19 November 2016 18:56:25 UTC, John Rumm
wrote:
On 19/11/2016 15:34, DerbyBorn wrote:



I will stick to fusing with the lowest capacity fuse to
suit the current of the appliance. I want the fuse to
blow as soon as possible if there is a fault.

Nothing wrong with fusing appropriately, but when dealing
with fault currents (in the technical sense), it makes
little difference if its a 3A or 13A fuse when you try
drawing 300A through it.

When you have an extension lead plugged into another, or an
old appliance, or something bought from China, it certainly
does.

You won't get a adequate fault current through too many
cascaded leads, but fitting all extension leads with 3A fuses
in case someone may cascade them seems a bit self defeating.

Plug fuses are available in 2A 3A 5A 7A 10A & 13A rating. Fitting
the correct one to leads is hardly self defeating, it prevents
fires.

How do you chose the "correct" fuse for an extension lead (assuming
the lead is designed for a 13A load)?

I can't imagine why you assume extension leads are all 13A rated.

I don't.

I assume that (non shonky) 13A leads are 13A rated, and will have a 13A
fuse in the plug.

Yes I realise that other leads are available, as I am sure you know full
well.

I
assure you they're not. 10A leads get a 10A fuse, 5A leads get a 5A
fuse etc. Hardly a challenge.

I was saying that for a lead of 13A rating, there is no point in
swapping fuses about each time you use them.

Are you proposing changing the fuse in the plug depending on what
you have plugged into the far end?

(and for most people the choice of fuse is 3, 5 and 13A - while
non standard options are available from more specialist places,
they are not commonly found in most shops)

Have people not got internet now?

Sure, but they need to 1) care, and 2) know enough to ask the question
in the first place.

Fault protection is what prevents fires. Modern kit built to
recognised standards will be adequately protected by a 13A fuse in
the vast majority of cases.

Ancient kit may require lower fusing, however I would not expect
most modern users to to be able to identify it.

Hence why people should pick the fuse according to power consumption

Huh?

So you are now expecting a user to 1) recognise that the kit is 40 years
old class 0 device with 10m of 0.5mm^2 CSA flex, and now work out what
fuse they should put in the extension lead?

Good luck with that one.

Substandard imported tat is another matter - plenty of it does not
even have provision for fusing!

Much does, and again the reason for a suitable fuse is obvious.

Seen any of those Chinese three pin unfused plugs?




--
Cheers,

John.

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