Fuse Problem

cajonlardo

We use an extension lead in order to place a deep fat frier under the cooker extractor.
This works fine until we unplug either the plug from the extension or the extension from the wall socket

When finished using the fryer and we unplug it the fuse will blow.

Same result with a new extension lead that an electrical trade supplier said is a quality one.

I dont have to use the fryer and I do not need to use an extension cord from that socket.

I would like to understand why it happens in order to know the wiring is safe.
Fwiw the fuse is a 10 amp and that is all that fits on that particular fuse socket in the fuseboard

Any ideas?

Edit - about six months ago an electrician looked at the wiring and said it did not need rewiring - this was before we started using the extension cord

meercat

cajonlardo wrote: »

We use an extension lead in order to place a deep fat frier under the cooker extractor.
This works fine until we unplug either the plug from the extension or the extension from the wall socket

When finished using the fryer and we unplug it the fuse will blow.

Same result with a new extension lead that an electrical trade supplier said is a quality one.

I dont have to use the fryer and I do not need to use an extension cord from that socket.

I would like to understand why it happens in order to know the wiring is safe.
Fwiw the fuse is a 10 amp and that is all that fits on that particular fuse socket in the fuseboard

Any ideas?

Edit - about six months ago an electrician looked at the wiring and said it did not need rewiring - this was before we started using the extension cord

If you’re still using fuses then most likely it does need rewiring

Chomper.

meercat wrote: »

If you’re still using fuses then most likely it does need rewiring

Many of the 80s domestic installations are in good nick

They have main bonding and earthing, RCD protected sockets .

A lot of issues crept into domestic work in the 90s when the boom came

meercat

Chomper. wrote: »

Many of the 80s domestic installations are in good nick

They have main bonding and earthing, RCD protected sockets .

A lot of issues crept into domestic work in the 90s when the boom came

If this installation has a 10amp fuse protecting a socket circuit I’d be surprised if it has rcd protection
I’d also doubt it has 16mm mains
Or 10mm equipotential bonding
Or earth at all light points and switches
Or immersion rcd protection

This installation is probably 40yrs old if it has a fuseboard still,possibly using red/black or even worse butyl rubber and I’d be concerned of the integrity of any installation of this age.
The op had some one look at it and said it’s fine but we don’t know if any tests were carried out or if any possible issues that I’ve highlighted were discovered
If a board with fuses is being replaced then a rewire will most likely be required

cajonlardo

Thanks all for the advise - I appreciate you taking the time

I am going to go ahead and get a rewire done
It is something I have set aside cash for and was the reason I had it inspected.

Aside from that, I am puzzled why the fuse goes AFTER appliance is switced off and. only when it is being unplugged. With my uneducated reasoning I would have thought ot would go while the appliance was drawing current.
I guess that is unimportant compared with upgrading the system.

Thanks again

meercat

cajonlardo wrote: »

Thanks all for the advise - I appreciate you taking the time

I am going to go ahead and get a rewire done
It is something I have set aside cash for and was the reason I had it inspected.

Aside from that, I am puzzled why the fuse goes AFTER appliance is switced off and. only when it is being unplugged. With my uneducated reasoning I would have thought ot would go while the appliance was drawing current.
I guess that is unimportant compared with upgrading the system.

Thanks again

Not sure why it’s blowing whilst you’re unplugging however the fryer typically uses 1.8kw and draws a load of 8.2 amps. This is close to your 10 amp fuse. If the extension lead is fully or partially coiled that can increase the ampage. If anything else is also on that circuit then that can push it over the 10amp threshold and blow the fuse.

That doesn’t answer your question I know but something important for everyone to know is

Never use an extension lead without uncoiling it fully

Cerco

Did you check the wiring on the appliance plug? Plug Connections can loosen from frequent plugging/unplugging. You could also check both plugs to make sure that neither are overheating.
I would never use an extension cord on a deep fat fryer because of the dangers of scalding, fire etc.
When you do rewire get a couple of sockets close to the extractor

maestroamado

Most appliances with heat element have 13 amp fuse.
If you get necessary 2.5 electric cable + 13 amp plug top + regular plug.
Put it all together and all be ok...

Water John

Is the ext lead a coil roll up one? That should be fully unwound when in use as it will overheat.

TheChizler

Water John wrote: »

Is the ext lead a coil roll up one? That should be fully unwound when in use as it will overheat.

Depends, they usually have a wound and unwound rating. Fryer would be on the higher end all right.

Water John

Wound rating can be quite low. Saw one melt in a factory and it wasn't running much.

whizbang

I saw a socket in a relatives house that quite often blew a fuse when anything was unplugged.

The earth links spot weld had broken, and allowed the earth wire and tag to float around, Along with a missing piece of the bakelite housing covering the live terminal.
When they inserted a plug it separated the terminals and allowed them to change the fuse.

Probably half of their single gang sockets screwed to the skirting boards had this broken earth link.

John.G

TheChizler wrote: »

Depends, they usually have a wound and unwound rating. Fryer would be on the higher end all right.

Obviously should be unwound but interesting to hear that they draw more current as well.

John.G

Water John wrote: »

Wound rating can be quite low. Saw one melt in a factory and it wasn't running much.

Just carried out a test on my deep fat fryer with a 30 ft extension lead.

UnCoiled V/A/Watts/PF 229.5/8.75/2008/1
Coiled V/A/Watts/PF 229.5/8.77/2013/1

Don't think 5 watts is going to set my ext. lead on fire but the point is still valid as closely coiled high current carrying cables can overheat with enough coils.

maestroamado

John.G wrote: »

Obviously should be unwound but interesting to hear that they draw more current as well.

These wind-up leads are completely unsuitable for anything that has a heating element kettle/deep fryer etc...

John.G

Agreed, better to have a electric drill on the end .

TheChizler

John.G wrote: »

Just carried out a test on my deep fat fryer with a 30 ft extension lead.

UnCoiled V/A/Watts/PF 229.5/8.75/2008/1
Coiled V/A/Watts/PF 229.5/8.77/2013/1

Don't think 5 watts is going to set my ext. lead on fire but the point is still valid as closely coiled high current carrying cables can overheat with enough coils.

The problem is you only measured the apparent power for the whole system, you have no idea how it is split between the fryer and cable. 8.77A is more than enough to melt a tightly wound cable, speaking from personal experience.

Edit: So assuming 1.5mm flex at 12.1 mOhm per metre at 60ft that's about 17W consumed by the cable, might be borderline depending on how tightly wound and thermally insulated it is. Plus inductive effects which I can't remember the maths for (probably cancelled out actually) I wouldn't be risking it anyway.

John.G

Yes, you are spot on, it was the inductive effect I was trying to measure but I also think they cancel each other out, I get 23 watts difference with the (2kw) load on the end of the ext. cable and just plugged straight into the socket.

Detour.

meercat wrote: »

If this installation has a 10amp fuse protecting a socket circuit I’d be surprised if it has rcd protection
I’d also doubt it has 16mm mains
Or 10mm equipotential bonding
Or earth at all light points and switches
Or immersion rcd protection

This installation is probably 40yrs old if it has a fuseboard still,possibly using red/black or even worse butyl rubber and I’d be concerned of the integrity of any installation of this age.
The op had some one look at it and said it’s fine but we don’t know if any tests were carried out or if any possible issues that I’ve highlighted were discovered
If a board with fuses is being replaced then a rewire will most likely be required

Most of those don't actually make an installation unsafe
(Excepting rcd protection for immersion).

40yrs old installation will be red/black , again nothing inherently unsafe there

cajonlardo

Detour. wrote: »

Most of those don't actually make an installation unsafe
(Excepting rcd protection for immersion).

40yrs old installation will be red/black , again nothing inherently unsafe there

Firstly - thanks everyone for advise .

Detour
Just realised today ts roughly 50 years old and as far as I have seen every single wire is black !

I have since been in touch with the electrician and am progressing towards rewiring

Its obvious that it will be money well spent and once it is done will bring peace of mind.
( that all aside - it is still a puzzling problem )

Detour.

cajonlardo wrote: »

Firstly - thanks everyone for advise .

Detour
Just realised today ts roughly 50 years old and as far as I have seen every single wire is black !

I have since been in touch with the electrician and am progressing towards rewiring

Its obvious that it will be money well spent and once it is done will bring peace of mind.
( that all aside - it is still a puzzling problem )

50 is old , if you mean black on the outside, well that's rubber and should be replaced

It's important to remember that re-wiring is fundamentally replacing wiring

Older Pvc wiring is not inherently unsafe and neither are fuses dangerous