Strajge wiring on lighting in Kitchen

[kongkong]

Untitled

• kongkong
• 6 May 2012
• 1

I am trying to replace my kitchen light and the picture i've drawn up here is what I originally found.

I bought a simple fluourescent 58W light from B&Q to replace the above light and it has the standard Live,Neutral,Earth fittings. I put both the lives,neutrals and earths in their respective places and the light socket did work for a while, but it seems to be blowing my fuse.

My questions are:
Why was the Live cable bypassing the light?
Why was the Neutral going into both the Live and Neutral fittings on the old light?
Why is my current light blowing the 5A fuse?

I must add that one of the neutral cables had a bit of red tape around it, perhaps this has some significance.

Anyway at the moment I'm stuck with no lights in the house until tomorrow morning. I'll have to replace the 5A fuse wire downstairs.

Do I need to fit a ceiling rose as currently I can't really tell if there is something hidden away in the floorboards. It would be difficult to trace this upstairs as it is underneath the bathroom.

Thanks in advance,

 

[wingcoax]

Your black with sleeving is the switch live, that is the return from the switch to the live connection in your light fitting. The two reds going through are loop in connections and should be connected as shown. your neutrals should be connected as shown. The tripping is because you have created a DEAD SHORT across the circuit.

 

[GaryMo]

The black insulated conductor that had red tape on it was the switched line and should be connected to the terminal marked as L. The other black conductor goes to the terminal marked as N.
The two reds are connected together and not the any of the L, N or E terminals of your light fitting. Basically one of them is a line in and the other goes to the switch, the return of which is a black conductor, marked with a red piece of tape in your case.

 

[sparkydude]

Oh Dear oh Dear, another diyer who does not look what they are doing when removing things.

The Lives did not bypass your light they are simply wired through it, Your wiring consists of two twin and earth cables each containing a red, black and bare earth which should be sleeved in green/yellow sleeving.

One of the cables will be the supply containing a live, neutral and earth .
the other will have a live and the black with the red tape on is the switched live to the light , and an earth.

If you think of the cables as pipes then it makes it easier for you to understand
the electricity flows through the supply into the connector block, then flows out to the switch which you could think of as a tap to shut off the electricity. Then returns to the light on the switched live ,

so you should have connected in your new light , 2x reds in a block on their own not connected to the light in any way .

one black with no red tape on in the Neutral terminal
one black WITH red tape on in the Live terminal

two bare earths sleeved in green and yellow sleeving to the Earth connection.

May i suggest that before you attempt any further electrical work you have a look at the numeropus diagrams posted on the site


Nick

 

[EFLImpudence]

Oh Dear oh Dear, another diyer who does not look what they are doing when removing things.

But he did.

He drew an excellent diagram of how it was when it worked.

Then thought and now for something completely different.

May i suggest that before you attempt any further electrical work you have a look at the numeropus diagrams posted on the site.

Do you think that would help?

 

[kongkong]

Cheers for the guidance guys, I think I've got a good idea what is going on now. I'll have another attempt tomorrow morning to get it all working.

 

[ban-all-sheds]

I am trying to replace my kitchen light and the picture i've drawn up here is what I originally found.

It can't be, can it?

How would a light (or indeed anything) work if all it had was a neutral connected?

Please learn how things work before trying to fiddle with them:

• http://www.google.co.uk/search?q=electrical+circuits+101
  
  
• http://kevinboone.net/electricity.html
  
  
• http://web.archive.org/web/20080213151445/http://www.kevinboone.com/domesticinstallations.html
  
  
• //www.diynot.com/wiki/electrics:books
  
  
• //www.diynot.com/wiki/electrics[/list]
  
  
  

  I bought a simple fluourescent 58W light from B&Q to replace the above light and it has the standard Live,Neutral,Earth fittings. I put both the lives,neutrals and earths in their respective places and the light socket did work for a while, but it seems to be blowing my fuse.

  That's to be expected.
  
  
  

  My questions are:
  Why was the Live cable bypassing the light?

  So that it wasn't permanently on - it goes to the switch.
  
  
  

  Why was the Neutral going into both the Live and Neutral fittings on the old light?

  It wasn't. Not all of the blacks are neutrals.
  
  
  

  Why is my current light blowing the 5A fuse?

  Because not all of the black conductors are neutrals, so connecting them all together has created a L-N short circuit.
  
  
  

  I must add that one of the neutral cables had a bit of red tape around it, perhaps this has some significance.

  "Some"?
  
  //www.diynot.com/wiki/electrics:lighting
  
  
  

  Anyway at the moment I'm stuck with no lights in the house until tomorrow morning.

  That sort of thing can easily happen when you don't see that not knowing how something works is a good reason for not fiddling with it.
  
  
  

  Do I need to fit a ceiling rose

  No.

 

[ban-all-sheds]

He drew an excellent diagram of how it was when it worked.

Excellent apart from not drawing the red tape and labelling a switched live "neutral".

Do you think that would help?

It should do.

 

[kongkong]

I understand you guys have a no nonsense attitude to DIYers like myself and I accept I've made a few simple mistakes. I probably could have spent longer researching it.

At the time assuming black for neutral I thought was a fair assumption to make. I'm living in an old house where everything is red/black/yellow+green. I didn't realise the significance of a red piece of tape at the time!

Thanks to your helpful posts above though I can see where I've made my mistakes and I think I can fix it all up tomorrow morning. Cheers guys.

 

[GaryMo]

I'm living in an old house where everything is red/black/yellow+green

Nothing to do with this topic but introduce another two colours - brown and blue and see where we could end up? It's bad enough with just red and black for some people.

Sorry and now back to topic!

 

[ban-all-sheds]

Or introduce brown black and grey...

 

[GaryMo]

Or introduce brown black and grey...

Minefield for an unsuspecting DIY'er.

 

[janner10]

What's the matter with these planks lately - just take a pic with phone or digital camera of the wiring before you disconnect.