Odd seventh wire in ceiling light?

[survive]

Hi, I am changing a ceiling light and found an odd configuration that I was hoping someone could explain so I don't put the new light on incorrectly.

There are three wires coming down from the ceiling. Two normal ones - black, red and yellow/green and one extra wire which is just a single wire in a grey plastic.

The two earths are taped together. The two lives are taped together (loop). The two neutrals are together in a choc block and attached to the light. The 'extra' wire is also attached to the light.

The light is old with no markings to I don't know if the the blacks or the 'extra' were connected to the live / neutral of the light.

There is only one ceiling light and on switch in the room.

Any advise would be greatly appreciated.

 

[Matmu1969]

a redundant spur?

 

[survive]

Just having another look at the extra wire, underneath the grey coating the wire has a red coating, so an extra live wire??

 

[Matmu1969]

Just having another look at the extra wire, underneath the grey coating the wire has a red coating, so an extra live wire??

Have a look and see if there is an another tucked into the ceiling cavity (black or brown under grey?) if it is a spur to another now defunct light it would've needed more than just a live!

 

[sparkwright]

Don't quite understand the problem.

Why don't you wire it as it was?

I would have thought the single wire on it's own goes to the live terminal of the light.

The two blacks go to the neutral of the light.

The two reds go together in a separate connector block.

Earths go together in an earth block.

Appologies if I have misunderstood the post.

 

[starspark]

seems very much to me that its the switched live cable that will go to live terminal of light, seen this many times in olderish installs.

 

[Lectrician]

My money is fully on the two blacks BOTH being neutral, and the 'extra' being the SWITCHED LIVE for the light.

Is this a light fitting switched from more than one location? They where often done this way in the 70's.

 

[LooPrEvil]

I have come across this previously. It was the continuous live to the switch in a late 1950s property. Obviously you are working on an older installation based on the wiring colours that are present.

 

[survive]

Thanks for the responses. After finding the mystery wire was red I wired it as live and the two black as neutral and it works fine. As suggested, effectively wiring it as I found it, but I just preferred to understand as well as just replicate!

Thanks.

 

[Matmu1969]

Sorry, my advice was on the belief that the wire was just hanging there with nothing to do, I didn't pick up that it was originally connected to the fitting. Sorry if I've confused the situation along the way!