100A fuse: is it really 100A?

[Cider Andy]

I'm assuming the fuse has a 100A continous current rating, rather than it melting at 100A, and then melting at 200A. Does anyone know if that's correct?

[pupp]

It has 100A stamped on it... no idea what that actually signifies but I assume all such fuses will be rated according to a consistent system and you will be replacing like-for-like by fitting a replacement of the same marked value.

I asked the same Q a little while ago and don't think it got a definitive response.

[grumbledoak]

In all other areas of electrics a fuse rating is the current at which it will fail, give or take a few percent 'tolerance'. I cannot imagine the TVR 100A fuse is any different.

[Paulathome]

Andy,
A 100 amp fuse is designed to take 100 amps continuous.
However if you look more deeply into the technical side of fuses, say a mains fuse for instance they will also have a time related measurement.
ie a mains fuse rated at 13 amps may take 30 amps for 2 seconds or 50 amps for one second before it blows. It would also take maybe 100 amps for several milliseconds before failure.
Based on this information I would imagine that our 100 amp fuse would probably pass 200 or maybe three hundred amps for a couple of seconds.
Just my tuppence.
Cheers
Paul

[puffsorted2]

Dunno but if you connect jump start leads up the wrong way round like I did last week (doh!!) it melts pretty quickly

[Cider Andy]

Thanks guys.

[spend]

Try a search for something like 'UL 275' there are standards bodies that define these things if you really want a definitive answer. There are other standards, but the principles are the same.

[Cider Andy]

Thanks Dave.

[Pasco]

Paulathome said:

Andy,
A 100 amp fuse is designed to take 100 amps continuous.
However if you look more deeply into the technical side of fuses, say a mains fuse for instance they will also have a time related measurement.
ie a mains fuse rated at 13 amps may take 30 amps for 2 seconds or 50 amps for one second before it blows. It would also take maybe 100 amps for several milliseconds before failure.
Based on this information I would imagine that our 100 amp fuse would probably pass 200 or maybe three hundred amps for a couple of seconds.
Just my tuppence.
Cheers
Paul

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