Unusual wiring in ceiling rose

[JonJonsson]

Hello everyone, hope all are well.
I'm changing a ceiling rose and have lost the diagram showing where everything was connected (to the old light) and now I'm unsure on some of the wires. There are three cables, with three wires each: -

1 - Brown, Blue, Bare Copper​

2 - Red, Black, Bare Copper​

3 - Red, Black, Blue (which has a connector terminal extending the wire with blue/yellow wire)​

I believe that the Brown from cable 1, the Red from cable 2 and the Red from cable 3 were joined together in their own block, not connected to the lamp, and that the two copper wires, from cables 1 and 2, were connected together in the earth, but I can't remember the rest.
I'm guessing that cable 1 is simply old wiring and that cable 2 is new wiring, but I've never seen a combination in a cable of red black and blue (and certainly not blue and yellow).
Any advice would be much appreciated. Thank you.

 

[littlespark]

Red, black, blue cannot be right. Is it just discoloured green sleeving?

Do you have a photo of the wiring as it is now?

Do you know where the brown/blue goes to? (Another light controlled by same switch or on to another room?)

 

[JonJonsson]

Red, black, blue cannot be right. Is it just discoloured green sleeving?

Do you have a photo of the wiring asThe it is now?

Do you know where the brown/blue goes to? (Another light controlled by same switch or on to another room?)

Hi, littlespark and thanks for your reply.
I've attached a couple of pics:

Wires1&2 - Black, Red, Copper is circled in red and brown, blue, copper is in the blue rectangle​

Wire3 - Red, Black, Blue is circled in red and the connector terminal (extended the wire to a blue/yellow sheath) is in the blue rectangle. To my eyesight, it doesn't look discoloured.​

The light is controlled by a switch that also controls two other lights (this one is hallway, but the switch controls the landing light and a light outside, next to the front door).
Thanks again

 

[JonJonsson]

Hi, littlespark and thanks for your reply.
I've attached a couple of pics:

Wires1&2 - Black, Red, Copper is circled in red and brown, blue, copper is in the blue rectangle​

Wire3 - Red, Black, Blue is circled in red and the connector terminal (extended the wire to a blue/yellow sheath) is in the blue rectangle. To my eyesight, it doesn't look discoloured.​

The light is controlled by a switch that also controls two other lights (this one is hallway, but the switch controls the landing light and a light outside, next to the front door).
Thanks again

 

[littlespark]

Ok.

It looks as though someone has used blue insulation over the bare earth wire instead of green/ yellow.


I can see two possible scenarios:

They’ve simply used blue instead of green, and it’s an earth

Or

They’ve used the bare earth as a neutral, very naughty. And the black of that cable has another function or is damaged somewhere.


I think the best course of action is to employ the services of a professional. Anything we suggest now would just be guesswork without testing the cables.

There may be a helpful forum member local to you that could do it for a few beers.

 

[westward10]

Can you show a wider pic ?

 

[Avo Mk8]

The light is controlled by a switch that also controls two other lights (this one is hallway,

If this ceiling rose light is also controlled by another switch elsewhere (two-way switching) there's a good chance it's option 2 in littlespark's post #5.
You could check if either switch is 2-way (three terminals) with a wire in each terminal, with the bare earth conductor (possibly sleeved!) occupying one of the terminals? .

As you probably know that is not a legitimate way of wiring the circuit!

 

[JonJonsson]

Can you show a wider pic ?

Sure, here you go.(

 

[westward10]

Definitely looks like the cpc (earth) has been sleeved and used as a neutral conductor, this is not permitted. You are going to need an electrician to look at that.