1A fuse in a 13A plug - what will happen?

[Discharged]

I'm trying to explain to my kid (8) why were have fuses in plugs, and he found a 1A glass fuse lying 'round and he asked me if we could put that into a 13A plug. I said 'no' it would blow if you plugged into the mains.

Then I wondered if that really would happen... So thought I'd better ask here for clarification.

What does happen if you put a too-lower rated a fuse into a plug? To my mind, what happens depends on the appliance being supplied - what current it draws.

Any idea on this, please?

 

[oldtimer]

Well first of all it would depend on the load so if you put it in a kettle,iron,toaster,washing machine the fuse would blow but if you put it in a standard lamp it would work but when the lamp or bulb comes to the end of its life then it could blow the fuse

 

[Discharged]

Thanks for that. So these 1A glass fuses would typically be aimed at protecting the simple, low demands of a much smaller appliance, like a clock radio perhaps?

 

[oldtimer]

Yes but there is a catch you cannot use these glass fuses in a plug top you have to use the same type of fuse and these are rated as 1,2,3,5,10,13 amps but most common fuses used are 3 and 13 amps in a domestic property the 1,2,5,10 are more common in a worplace

So Kettle ,toaster,washing machine, would be 13 amps
Standard light, PC, printer,clock radio would be 3 amps

 

[Peter Stanley]

this is ohm law P = I x V
The appliance is 800watts divided by 230 = 3.5 Amps
put a 1 amp fuse in plug it will go bang

 

[telectrix]

simply put, a 1A fuse will withstand a wattage if 230watts indefinitely, but can take around 1.45x that for up to an hour before popping.

 

[UKMeterman]

There is also another difference, when there is a short circuit hundreds or thousands of amps can flow. This high current will make an arc, a proper 1A plug fuse might make a bang but contain the arc. A glass fuse will do something like this ERA Technology Ltd - Low Voltage Electrical Product Testing

 

[dingledong]

but you get glass fuses in alarm panels and other things to . so i dont think it will explode unless you shoe a high voltage through, and even then i'm not sure

 

[Mr.Ian]

1amp fuses are used in 2 pin shaver adaptors but even then they are ceramic and not glass, glass fuses are used mainly to protect low current circuits on pcbs as far as i've found. Glass fuse in a plug with a faulty circuit might shatter the glass whereas the ceramic fuses contain the arc. If you powered say a vacuum cleaner or toaster with a 1 amp fused plug I doubt it'd even go bang it'd just melt the fuse element straight away. Interesting test all the same !!!!!

 

[UKMeterman]

Hi,
It all depends on the prospective fault current and energy avaliable into a fault. A glass fuse can clear a fault of 35A and in practice a bit more, ok for the safety low voltage side of some power supplies. The test shown is a fuse subject to a current of about 6,000 amps and has a lot more energy avaliable!!

 

[Rampage]

I don't think a glass fuse is the correct diameter for a 1363 anyway is it?

 

[kippaxkid]

all interesting theories.......slightly undone by the fact that a glass 20mm fuse and a cartridge fuse are different sizes.
kitkat wrappers would be required.

 

[JamesBrownLive]

There is also another difference, when there is a short circuit hundreds or thousands of amps can flow. This high current will make an arc, a proper 1A plug fuse might make a bang but contain the arc. A glass fuse will do something like this ERA Technology Ltd - Low Voltage Electrical Product Testing

So how is that fuse blowing when there doesn't appear to be anything connected to the plug :book:

Cheers

 

[MarkieSparkie]

all interesting theories.......slightly undone by the fact that a glass 20mm fuse and a cartridge fuse are different sizes.
kitkat wrappers would be required.

Wrong! I have 1 inch, 1A, LV, glass cartridge and 1 inch, 1A, BS1362, HBC, Ceramic cartridge fuses in front of me as I type.

 

[ian.settle1]

I'm trying to explain to my kid (8) why were have fuses in plugs, and he found a 1A glass fuse lying 'round and he asked me if we could put that into a 13A plug. I said 'no' it would blow if you plugged into the mains.

Then I wondered if that really would happen... So thought I'd better ask here for clarification.

What does happen if you put a too-lower rated a fuse into a plug? To my mind, what happens depends on the appliance being supplied - what current it draws.

Any idea on this, please?

A glass fuse does not comply with BS1362 for a start so should not be fitted to a plug top.

 

[poppypiesdad]

Glass fuses should not be used as they do not comply with any B.S. , being glass they can shatter leaving glass , creating a danger , hence why they are ceramic to retain the molten metal and can be removed without danger of injury

What would happens depends on the rating of the glass fuse 12v 3amp , would pop if you put it in a toaster plug, 240v 13amp glass fuse would work , but not advised

JAmie

 

[Cyberprog]

Ceramic body, and Sand filled iirc for BS1362

 

[kippaxkid]

Sorry about that. My mistake. Didn't realise that 20mm was an inch........ (better half will be quite pleased with the reassessment.)
Back to the fuses.

(Why do I get sucked in??????)

A HBC fuse is not a plug top fuse.
Go round the house and see if you can find a three pin plug that doesn't have scrunched up baco foil in it, take out the fuse and measure it. You may notice a difference.
Ever wondered why there are so many styles of fuses?

 

[SirKit Breaker]

BS1362 fuse must be fitted to a Plug. 3a up to 700w, and 13a above 700w, unless the appliance manufacturer instructions state otherwise.

Cheers...........Howard

 

[Cyberprog]

BS1362 fuse must be fitted to a Plug. 3a up to 700w, and 13a above 700w, unless the appliance manufacturer instructions state otherwise.

Cheers...........Howard

I do wonder about that over 700w should be 13A, had a Belt Sander from B&Q with .75mm2 cable, and a 13A fuse...