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Fuse Box

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elMickotanko

New Member
Hi,

I have recently moved house. The upstairs mains circuit keeps tripping when my girlfriend uses her hairdryer. I checked the fuse box and it is only 6A for upstairs, whereas its 13A everywhere else. Is there any way i can change this to be 13A? My computer, Amp, keyboards, TV etc is upstairs.

Cheers,
Mick.
 

Nigel Goodwin

Super Moderator
Most Helpful Member
I seriously suggest you either rewire the house correctly, or get an electrician to do it for you.

In the UK electrical sockets should be wired on a ring main, usually seperate ones for each floor, with a 25A fuse feeding it. Lighting circuits, again, are usually seperate for each floor, and use a 5A fuse.

There should be no sockets fed from either 13A or 6A fuses at the fusebox?.
 

elMickotanko

New Member
Thanks for the reply,

I checked the fusebox again, there are 11 fuses, not counting a separate double one for the shower. I noted exactly whats marked on them:

Code:
MAIN - 100A;

G&K BEDROOM - 6A  (Now my room and the study i presume);

LIGHTS - 10A;

The next three are OFF and unmarked  (10, 10, and 20A);

unmarked - 20A  (might be the garage);

SKT 1/2, Kitch, centrl heat, shaver - 20A;

SKT 1/2, Kitch - 32A;

next three are unmarked, ON and are all 32A.
Sorry, I dont why I thought it was 13a.
I take it I cant just replace that 6A fuse? in case the wire is only rated at 6A or something?
 

stevez

Active Member
Fuses are there to keep the wires from overloading. As you suspect, thicker wires can handle more current therefore fuses of greater capacity would be employed with thicker wires. Don't be tempted to just look at the wire size at the fuse - and possibly conclude that the wire size at the fuse represents the minimum wire size thru the entire circuit. While it should be it also might not be the case.

This is just stuff to think about and help reinforce the "get a skilled person involved" advice that's already been given.

A couple of questions came to mind -

A. What is a ring main?

B. Can the fuse sockets or holders accept fuses of larger capacity? Here in the US they can. My first house was wired with 15 A circuits however the previous owner, frustrated with blown fuses, worked his way up to 30 A fuses in all positions. How he didn't burn the house down escapes me.
 

RODALCO

Well-Known Member
A ring main is commonly used in the UK and Scotland.

RINGMAINS
It means a circuit is ran from a 30 Amps fuse in say 2.5mm² through various powerpoints and the end of the cable will meet back at the same fuse again. so the power flows in both directions from the source.
Then the UK plugs have an internal fuse 3, 8, 13 Amps to protect the plugged in appliance.

BRANCH CIRCUIT
The single branch circuit is feeding powerpoints and ends somewhere well away from the source of supply, in this case the wire has to be 6 mm² to allowe for the current carrying capacity and minimise voltage drop.
 

Nigel Goodwin

Super Moderator
Most Helpful Member
elMickotanko said:
Sorry, I dont why I thought it was 13a.
I take it I cant just replace that 6A fuse? in case the wire is only rated at 6A or something?
I'm bemused by a 6A fuse feeding anything?, never mind power sockets - unless you know what you're doing?, you really need to seek professional help.
 

Nigel Goodwin

Super Moderator
Most Helpful Member
RODALCO said:
A ring main is commonly used in the UK and Scotland.
Last time I looked Scotland was part of the UK? :D

UK and ROI would be OK though!.

RINGMAINS
It means a circuit is ran from a 30 Amps fuse in say 2.5mm² through various powerpoints and the end of the cable will meet back at the same fuse again. so the power flows in both directions from the source.
Then the UK plugs have an internal fuse 3, 8, 13 Amps to protect the plugged in appliance.
8A isn't usually one, 2A, 3A, 5A, 7A, 10A and 13A are the ones you see, with 3A, 5A and 13A being the common ones.
 

RODALCO

Well-Known Member
Nigel
I have done some electrical work in Norwich years ago, around 1982 when I still lived in The Netherlands.
I recall the UK plugs with the little fuses, the 8 Amp was a value which was stuck in my mind.
I see there are quite a few other values available too now.

I agree too that Elmickotanko needs to get the landlord get a registered electrician to sort out the wiring in that place. A 6 Amps circuit is probably wired in 1mm², which is only rated for lighting circuits.

It's interesting to read that two 10 Amps and one 20 Amps circuit have been turned of or tripped.
That perhaps needs looking at by an electrician too. Perhaps a faulty power cable has been disconnected somewhere and the powerpoints have been illigally wired to the 6 Amps lighting fuse.

Does the light go off when the haidryer overloads the sockets ?
That test will prove that illigal wiring has been done somewhere.

The fuse or MCB protects the wiring in in the house, and under NO circumstances should a higher value been used otherwise you can burn the place down with all further consequences.
 

Nigel Goodwin

Super Moderator
Most Helpful Member
RODALCO said:
Nigel
I have done some electrical work in Norwich years ago, around 1982 when I still lived in The Netherlands.
I recall the UK plugs with the little fuses, the 8 Amp was a value which was stuck in my mind.
I see there are quite a few other values available too now.
I've never seen, or heard of, an 8A plug fuse - just checked catalogues, other standard values are 1A and 10A (that I didn't mention before), but no 8A.
 

Hero999

Banned
I've never heard of an 8A fuse either, you must've been dreaming.
 
Wow, you guys have wierd fuse values. All of ours are multiples of five. Also, all of our mains lines in the house (120v) are 15A for standard and 30A for stove plugs. Guess thats just canada for you, eh. And even then, we dont use fuses, we use breakers. Used to use the old screw-in fuses, but we'd just drop a penny in there first, so the fuses wouldnt blow :p
 

Nigel Goodwin

Super Moderator
Most Helpful Member
ParkingLotLust said:
Wow, you guys have wierd fuse values. All of ours are multiples of five. Also, all of our mains lines in the house (120v) are 15A for standard and 30A for stove plugs. Guess thats just canada for you, eh. And even then, we dont use fuses, we use breakers. Used to use the old screw-in fuses, but we'd just drop a penny in there first, so the fuses wouldnt blow :p
The fuses we're talking about are in the mains plugs, all UK plugs are three pin, 13A, and have a replaceable fuse inside - so although every socket in the house is capable of supplying 13A, each individual appliance has it's own fuse, sized accordingly.

Modern 'fuse' boxes use MCB's (Minature Circuit Breakers), but older ones still have the old fusewire fuses - often the MCB's are too sensitive, and can blow for no reason, so it can be advantageous to replace them with fusewire ones.
 
Ahhh, I remember those. Sorry, must have skipped that part. Saw them in Oz when I was there six years ago, along with the on-off switch on the wall plug. Its a great idea, and I dont know why we dont have them here. Im going to have to get them for when I build my house (in the 120v version though)
 

Nigel Goodwin

Super Moderator
Most Helpful Member
ParkingLotLust said:
Ahhh, I remember those. Sorry, must have skipped that part. Saw them in Oz when I was there six years ago, along with the on-off switch on the wall plug. Its a great idea, and I dont know why we dont have them here. Im going to have to get them for when I build my house (in the 120v version though)
There's not much point using different sockets to the rest of your country, and it's probably not legal either?.
 

elMickotanko

New Member
RODALCO said:
Nigel
I have done some electrical work in Norwich years ago, around 1982 when I still lived in The Netherlands.
I recall the UK plugs with the little fuses, the 8 Amp was a value which was stuck in my mind.
I see there are quite a few other values available too now.

I agree too that Elmickotanko needs to get the landlord get a registered electrician to sort out the wiring in that place. A 6 Amps circuit is probably wired in 1mm², which is only rated for lighting circuits.

It's interesting to read that two 10 Amps and one 20 Amps circuit have been turned of or tripped.
That perhaps needs looking at by an electrician too. Perhaps a faulty power cable has been disconnected somewhere and the powerpoints have been illigally wired to the 6 Amps lighting fuse.

Does the light go off when the haidryer overloads the sockets ?
That test will prove that illigal wiring has been done somewhere.

The fuse or MCB protects the wiring in in the house, and under NO circumstances should a higher value been used otherwise you can burn the place down with all further consequences.
I dont know about down in the UK, but we dont have 8A fuses here in scotland! :D

No its not on the lighting circuit. upstairs was added by the 2nd last owner who was a builder, it was a bungalow before. I just cant get my head round why he would wire the whole upstairs for 6A? He is known around my area as being a nice guy, and reputable for his work. Certainly not a cowboy. I wouldnt have thought it would be that much cheaper to use 6a cable, or any less hassle?

i dont know about the three that are off, but they were off when we moved in and everything in the house/garage works.

Thanks for all your help, i know a friend of a friend who is a sparky, ill call him.
 

Dean Huster

Well-Known Member
"RINGMAINS
It means a circuit is ran from a 30 Amps fuse in say 2.5mm² through various powerpoints and the end of the cable will meet back at the same fuse again. so the power flows in both directions from the source.
Then the UK plugs have an internal fuse 3, 8, 13 Amps to protect the plugged in appliance."

From that description/definition, it sounds like it ends up being a parallel feedline to the loads, strictly against code here in the U.S.

I did not realize that "powerpoints" in the U.K. had internal fuses. Sounds like a bit of a hassle (and extra expense) to me. But then, most of us prefer what it that we're used to.

Dean
 

Hero999

Banned
Dean Huster said:
I did not realize that "powerpoints" in the U.K. had internal fuses. Sounds like a bit of a hassle (and extra expense) to me. But then, most of us prefer what it that we're used to.
The power points don't have fuses, it's the plugs that have fuses and it's safer that just having a fuse built into the appliance.
 
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