Blimey 2012, almost up to date.

On an allied subject, Remember some time back an incident where a person
died due to a fuse not blowing when a mains cable was taken up by an old
style beater hover, mostly made of metal. The cord was not the one on the
hoover but one on a table light, which only had a 13 amp fuse not a lower
one so it never blew.
However I'd not suggest taking up live cables in any case to be honest!
Brian

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The Sofa of Brian Gaff...

Blind user, so no pictures please!
wrote in message
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On Wednesday, November 7, 2012 at 6:40:34 PM UTC, David Robinson wrote:
Not my question, or belief, but found here...

http://forums.digitalspy.co.uk/showthread.php?t=1755197


Is there a counter-argument?

Thanks,
David.

To "the fuse is there to protect the cable" ? Hmmm, that's rather to vague,
and technically incorrect. I think you need to ask what are we protecting
really, and I beg to differ that the fuse is there to protect the cable,
here are some reasons why:

Really what we are protecting is ourselves and other property from
electrocution and fire, The simple fact is that if the cable is overloaded
then it will melt and cause a fire, it will then also short out the supply
causing further risk. To illustrate lets consider the service fuse in your
electricity supply, without it any short or overload would probably take out
at least part of your street.
It's easy to forget that the fuse is there to protect against overload
because in most cases it's blown due to a direct short, but if you are
running a 3KW heater on a 5A lighting circuit with a 13A fuse, that wire is
going to melt sooner or later, but even assuming it doesn't, over time the
excess heat will make the plastic brittle and one day it will crack, perhaps
when you pick up the cable! A 13A fuse will certainly protect a direct short
an a 3A cable as it won't really have time to melt before the fuse blows,
but if you want a demonstration of what can happen try dropping a some 13A
stranded wire across a 12V car battery, make sure you aren't holding it and
there is nothing combustable around though as the whole length will
instantly burn all it's length before it vapourises- It's quite spectacular,
yo might want to wear suitable eye protection as it could be quite bright.