Audiophile Mains Fuses - Boon or Boooom(!)?

[anthonyTD]

hi andre,
i totaly understand and agree with your sentiments, however, as stated by others the fuse in the plug is only there to protect the lead and not the equipment! so,,,if the lead is rated at 13amp then it should have a thirteen amp fuse fitted, if however the lead is of a fixed type, ie; not a detachable IEC [known as a kettle lead to most of us]type then it can be argued that the fuse in the plug is the correct fuse rating for the equipment and not just the lead.
a lot of consumer equipment these day for eg, hair dryers, and other house hold devices of similar dont have any other means of protection apart from the fuse in the plug!
Athony,TD...

[Rare Bird]

Hi Anthony
Sorry yes what i was trying to say is for instance one of my amps came with the original flimsy mains lead that can't be rated at no more than 6 Amp,if that, which is fine for this amp.. who ever fitted a 13Amp fuse in the plug i totally disagree with what they have done.

[anthonyTD]

Hi Anthony
Sorry yes what i was trying to say is for instance one of my amps came with the original flimsy mains lead that can't be rated at no more than 6 Amp,if that, which is fine for this amp.. who ever fitted a 13Amp fuse in the plug i totally disagree with what they have done.

[Beobloke]

if the lead is rated at 13amp then it should have a thirteen amp fuse fitted,

No it most certainly should not. Are you seriously suggesting that if I choose to make myself up a mains lead or two using some of the spare armoured mains cable we have here at work, which is rated at 20A, then I should be putting a 20A fuse in the lead to my CD player?!

The lead should have a fuse appropriate to the power rating of the item to which is connected fitted.

[anthonyTD]

No it most certainly should not. Are you seriously suggesting that if I choose to make myself up a mains lead or two using some of the spare armoured mains cable we have here at work, which is rated at 20A, then I should be putting a 20A fuse in the lead to my CD player?!

The lead should have a fuse appropriate to the power rating of the item to which is connected fitted.

hi adam,
please re-read what i have written, and think about it.
A...

[Reid Malenfant]

You see this is the problem Knowing whether to rate the fuse for the cable fitted to whatever it is or for the equipment itself

Anthony gave a good example of a bit of kit that probably hasn't got a standard internal fuse a little earlier - a hairdrier (not that i need one ). These tend to have fixed leads so it'd be sensible to rate the fuse for the equipment. It'll more than likely have a fairly thin flex as well which would indicate to use less than a 13 Amp fuse, in fact 7 Amp might be more appropriate for a 1.5KW load. They do have thermal fuses though incase of overheating (fan motor giving up or blocked vents) will cause this to blow & prevent a fire.

I tend to always rate the fuse to the equipment & ignore the cable (unless it is undersized when it wouldn't be used in the first place ). It is pefectly safe to use a 13 Amp fuse on 1.25mm^2 cable as long as the equipment has it's own internal fuse. As has been pointed out on a number of occasions the fuse in the mains plug is only protecting the cable if the equipment is internally fused.

On the other hand if there is no internal fuse then the one fitted in the plug must be rated to protect the cable & the equipment. You just need to hope that either the manufacturer has fitted an adequate mains cable (most kettle manufacturers take note ) or you are competant enough to make sure you never underate the cable if fitting it yourself

[anthonyTD]

cheers mark,
i hope that clears things up, i just wish people would read the whole thread before comenting on one post!
we have already established that the maximum fuse rating one can use on a domesticly spured socket is 13 amp!
mark has re-explained the rest for those not sure of the key issues discussed in the whole thread!
Anthony,TD...

[Reid Malenfant]

No it most certainly should not. Are you seriously suggesting that if I choose to make myself up a mains lead or two using some of the spare armoured mains cable we have here at work, which is rated at 20A, then I should be putting a 20A fuse in the lead to my CD player?!

Apart from the fact that you wouldn't fit a 20 Amp fuse in the plug, the plug itself is only rated to 13 Amps I can assure you that if you continuously draw 13 Amps through a mains plug it'll get quite warm...

As i mentioned in my previous post, i fit a fuse that is rated for the equipment, but as long as whatever you are connecting this hypothetical lead to is internally fused you can rate the fuse to protect the cable

Having had a brief think about this most household electrical items need to be fused according to the item itself as generally they don't have internal fuses (that i know of). Toasters, electric cookers, food mixers, refridgerators etc would need a fuse rating according to the current draw of the item concerned.

Electronic household items tend to be internally fused however

[Rare Bird]

Apart from the fact that you wouldn't fit a 20 Amp fuse in the plug, the plug itself is only rated to 13 Amps I can assure you that if you continuously draw 13 Amps through a mains plug it'll get quite warm...

I'm actually shocked at our kettle 2500-3000Watt, no wonder our elecky is sky high.

[Reid Malenfant]

I'm actually shocked at our kettle 2500-3000Watt, no wonder our elecky is sky high.

Now go & look at the cable connecting it to the mains & see what guage it is

I'll be surprised if it's 1.25mm^2 Manufacturers always appear to under-rate the cables feeding kettles, i guess it's because the figure it won't be permanently switched on But just supposing it was continually boiled for lots of hot water....