Micro circuit breaker needed

[djmagnifique]

Hi, I need to get hold of a micro circuit breaker to replace a fuse that keeps blowing in my consumer unit (due to dodgy council wiring making 9 wires going into a ceiling fan I fitted, you don't want to know how the thing is wired up, all i'll say is that it doesn't make sense to me). Its only for the upstairs lights and is rated at 5 amps and it oly blows when the bulb in the fan burns out. The fuse is a really old type that has 2 long pins that go into the consumer unit.

Anyone know where I can get one from?

The house is no longer a council house as I bought it a few years ago.

Cheers.

 

[mfarrow]

Does it have a manufacturer's stamp on it? Wylex, per chance?

 

[sparkwright]

a miniature circuit breaker. what is the make of the fuse board?
wylex?

perhaps we could help you wire that ceiling fan correctly.
it should be easy to do, once you've confirmed which cable goes to the light switch. does the switch control just the one light?

 

[securespark]

Perhaps the CB is doing its job, breaking when the lamp fails?

 

[sparkwright]

i assume from the op a 5A re-wirable fuse is currently in use, shouldn't normally blow when a lamp fails should it?

 

[djmagnifique]

Yes, it is a Wylex unit. and it is a 5A re-wireable fuse.

the fan is wired correctly, it's the house that's wired bad. 3 live, 3 earth and 3 neutral wires in 2 bedroom light fittings (haven't looked at any of the others)

I used to have a fan in another room which when I fitted it I had to wire like this , I had to wire it all E to 1 point, all L to 1 point (not connected to the actual bulb) 2 N to one side of the bulb and 1 N to the other, if I got the N wires mixed up that would also blow the fuse. Tjis is how the original light fitting was wired.

when I removed it I tried to wire the original light fitting correctly (E to E, N to N and L to L) but that always blew the fuse.

 

[AndyPRK]

That is because 1 wire is the wire to the switch.

If you connect all L to L and all N to N
when you turn the switch on it shorts L & N and blows the fuse.

The single black or N wire connected to the bulb should have red sleeve/tape round it to indicate it is a live

 

[electronicsuk]

It sounds as if your wiring is perfectly normal. Sad to say, the problems may well be caused by something you have done by working on a circuit that you don't understand. It's quote normal for a type B MCB to trip when a lamp fails, but not so with a fuse. How heavily loaded is the circuit during normal use?

 

[djmagnifique]

That is because 1 wire is the wire to the switch.

If you connect all L to L and all N to N
when you turn the switch on it shorts L & N and blows the fuse.

The single black or N wire connected to the bulb should have red sleeve/tape round it to indicate it is a live

never been anyting on the single N wire to indicate that it is live.

It sounds as if your wiring is perfectly normal. Sad to say, the problems may well be caused by something you have done by working on a circuit that you don't understand. It's quote normal for a type B MCB to trip when a lamp fails, but not so with a fuse. How heavily loaded is the circuit during normal use?

I wired the fan up the same as the original fitting that was there.

Anyway, back on topic, can anyone tell me where I can get a mcb to replace the re-wireable fuse that blows when the bulb goes pop?

 

[1john]

tlc-direct

you have a problem if your rewirable fuse blows each time a bulb blows. Please get a spark to do a periodic inspection report on your installation, you may have problems there that could be more serious than you think, they could be or become endangering to you, your family, pets or cause a fire in your property.

 

[securespark]

i assume from the op a 5A re-wirable fuse is currently in use, shouldn't normally blow when a lamp fails should it?

I have to disagree!

Recently I have been to the same customer who has GU10's in the kitchen. Despite pleas to use good quality lamps, I have been back 5 times to replace the fusewire.

It is an ancient fusebox, so swapping out for a breaker is sadly not an option.

 

[skenk]

Did you not teach them how to replace it themselves?!

I've sen the same thing with GU10's blowing 5A fuse wire. £25 to replace the fuse wire the first time, showed her how to do it (safely), have since had more than £900 of work from them!

 

[ban-all-sheds]

dodgy council wiring making 9 wires going into a ceiling fan I fitted,

As others have said, that isn't dodgy, that's the commonest system in use.

it doesn't make sense to me

Then please spend some time learning how it works so that it does make sense to you before you try doing any more work.

• http://www.diynot.com/wiki/electrics:lighting
• http://www.diynot.com/forums/viewtopic.php?p=75416#75416
• http://web.archive.org/web/20080213...inboone.com/domesticinstallations.html[/list]
  Then you might not end up making a mistake like this:
  
  

  when I removed it I tried to wire the original light fitting correctly (E to E, N to N and L to L) but that always blew the fuse.

 

[JohnD]

Anyway, back on topic, can anyone tell me where I can get a mcb to replace the re-wireable fuse that blows when the bulb goes pop?

They can be obtained, but you would have to post a photo of your consumer unit first, for identification, and the work is supposed to be done by a competent electrician.

Best advice would be to get it inspected and see if there are faults that need to be corrected.

If you change to more ordinary light bulbs, and use more CFLs, then the problem will probably go away.

 

[AndyPRK]

The single black or N wire connected to the bulb should have red sleeve/tape round it to indicate it is a live

never been anyting on the single N wire to indicate that it is live.

Well next time you disconnect a fitting, fit one so you don't get yourself confused when wiring it back up