Replacing ceiling light - old cabling is confusing!

[psy29]

Hi

I am attempting to replace an old ceiling light and replace it with a new pendant.

The house was built in 1971 and still has the same electrics from when it was first built.

I started removing the old light and found out the 3 cables (brown, blue and green/yellow) from the light were connected into a choc box. These 3 were in turn connected to a further 2 choc boxes as shown in the picture:

Untitled

• psy29
• 20 Apr 2014
• 1

The same 3 colours continued into the 2 choc boxes, but then as you can see when they go into the choc boxes they change colour:

brown to red
blue to green
green/yellow to black

I tried rewiring using 'modern' colours i.e.

from the pendant brown joining ceiling cable red
from the pendant blue joining ceiling cable black
from the ceiling cable green into earth

As soon as I turned the power on the fuse tripped. So instead I tried to replicate what I had found when I disconnected the old light i.e.

from the pendant brown joining ceiling cable red
from the pendant blue joining ceiling cable green
from the ceiling cable black into earth

As shown below and this now works!

Untitled

• psy29
• 20 Apr 2014
• 1

I'm a bit baffled how this works as I have just replaced all the other lights in the house and found different configurations each time.

I did have an electrician check the cabling in the house and although he said it was old he said it was safe. He comes from the school of thought that if it ain't broke don't fix it, but he did say all the pendants needed to be replaced.

As the light works I'm happyish but naturally concerned if it is correct and safe. What's you opinions chaps?

Thanks

 

[AndyPRK]

As can be seen from your first pic
The cables are the wrong way round.

Black should goto blue.

It works as you have swapped their function back at the other end.

It would be sensible to correct this if the other end if the white cable is access able.


Why did he say the pendants needed replacing?

 

[psy29]

Thanks AndyPRK

So just for my understanding, the white cable leading into the ceiling has been connected incorrectly into a junction box - I guess somewhere under the floorboards?

The electrician reports states:
"At all of the switches and sockets there is either no earth sleeving or the old version which is green only. To meet the current standards it needs to be green and yellow.
At all of the lighting points and switches there should be an indicator brown sleeving to show its a live conductor.
The pendant lights really need changing as there is signs of crushing on a couple and the general installation of them is poor."

 

[AndyPRK]

Yes you may find that if you pull that white cable genentally another junction will come down.

It's probably best left alone though.