This one had to be my favourite:
dominicgross - taken from [url said:
http://www.blue-room.org.uk/index.php?showtopic=5731&st=0]While[/url] doing a tour in sweden we noticed that all the 13amp (euro style) plugs had had nails put in the
fuse holders!
When asked the reason for this they answered - 'We have good earth'...???
I will be in Sweden and Denmark next month, so I will keep my eye out for such novel uses for nails!
Recently received this explanation from a friend of mine:
As for the question -
current is
current, irrelevant of the
voltage that it is at as far as a
fuse is concerned. IE if you take the 10 amp 240 volt
fuse and slap it into the car and then try to pull 20 amps it will go futt.
Where the difference is, is a 240 volt
fuse is capable of interrupting the
current flow of a higher potential than the 12 volt jobby without exploding/shattering and generally f**king over your
fuse holder.
As for the heat thing, you generally find that the car fuses (read low
voltage) are not as well made (read cheap) as the 240 volt ones and as such tend to give off more heat and when used in a screw in type
fuse holder they have a higher contact resistance (more heat) as they generally do when used in the clip-in varieties that have larger contact areas and so on.
The main reason though is the afore mentioned ability to break higher voltages, as, when the
fuse goes
splat it really does go
splat leaving a fine coating of copper all over the inside of the glass/
ceramic tube. This allows the possibility of conduction if you then add ionized gas (created when the
fuse goes futt) to the formula and say an inductive load.
Now the other problem you get is most
fuse holders that you come across will tarnish with time equalling more heat which equals faster tarnishing which equals more heat which... You get the picture.
And there is the other problem, the users. The amount of time that I have seen 20 amp car fuses come out of dimmers begs disbelief. This is a good way to really f**k things up because not only do you toast the
fuse holder you toast the cable as well.
240 volt fuses tend to be made of
ceramic or a high temp glass to withstand the high temperature of a piece of copper/nichrome turning to liquid and the HRC variety then add a sand fill to snub out any arcing if it occurs.