Ceiling rose with twin wire, no earth?

[aliasx51]

I have a ceiling rose with a twin live / neutral wire and no earth.



This is unexpected as the house was built in 1986 and the light switch does have an earth.

Can I still use this with light fittings that are not double insulated?

 

[flameport]

Probable that the cable showing is actually an old flex from a ceiling rose concealed up in the ceiling behind that decorative? plaster moulding. Or perhaps a junction box hidden in the ceiling.
In any event, only double insulated fittings can be used with that.

Real solution is to find the original wiring in the ceiling and connect the new light fitting properly.

 

[PBC_1966]

Definitely looks like flex there, so I would certainly want to get access above to see what has been done.

 

[aliasx51]

Thanks both! I went into the loft and found the flex. It looks as though above the ceiling there is a box with 3 wires going into it, and then the single live/neutral flex wire coming out of it.

I've included a photo of it below; can you tell me what is likely happening here? What should I do to get an earth through the ceiling rose - put all 3 wires through the ceiling and then use the fitting to connect them?



Any ideas why it has been done this way? There is a joist (as you can see) which partially obscures the hole, but the wires should fit through easily.

 

[flameport]

That is the old ceiling rose.
Options:
easy: fix that ceiling rose to the side of the joist, remove the 2 core flex and fit a 3 core flex through the ceiling to the new light fitting.
not so easy: remove the ceiling rose, pass all 3 cables through the ceiling, connect to the new light fitting. This will probably require additional connectors for the wires, wires may be difficult to fit into the new fitting, risk of connecting wires incorrectly.

 

[stillp]

Any ideas why it has been done this way?

Someone didn't want to obscure the decorative plasterwork?

 

[aliasx51]

@flameport Thanks - is a ceiling rose the same as a junction box? Also, I had the power to the entire flat off at the master circuit before inspecting this, however I picked up a live feed with my cheap voltage pen tester when inspecting the 3 wires. Is this common / expected - could it actually be live? The live wire underneath the ceiling into the flat is definitely not live.

@stillp unlikely as there was another ceiling rose on the other side. Possibly newly installed, although seems like an odd solution to have 2 - is this common practice?

 

[stillp]

is this common practice?

Anything is possible, as you've discovered!

 

[stillp]

The live wire underneath the ceiling into the flat is definitely not live.

How has that been proven? Cheap voltage pen testers are not reliable, you need a two-terminal device.

 

[aliasx51]

@stillp I used this Rolson All Purpose Voltage tester: http://www.amazon.co.uk/gp/product/B001XQX01G?keywords=voltage tester&qid=1457811820&ref_=sr_ph&sr=1

Can you recommend a better one?

 

[EFLImpudence]

"All purpose"

Not even good as a screwdriver.

 

[flameport]

is a ceiling rose the same as a junction box?

Yes, it's just one with terminals appropriate for lighting and has a flex outlet.
You could replace it with a 4 terminal junction box, but no real point as the rose is already there.

 

[stillp]

@stillp I used this Rolson All Purpose Voltage tester: http://www.amazon.co.uk/gp/product/B001XQX01G?keywords=voltage tester&qid=1457811820&ref_=sr_ph&sr=1

Can you recommend a better one?

Something more like this https://www.yourelectrics.com/produ...&network=pla&gclid=CL_jtJ_5u8sCFcFsGwodNwcMJw
Somewhat more expensive, but the single-pole ones can give false positive or false negative readings. A multimeter would be better than that screwdriver thingy, and you can get a cheap one for under a tenner.

 

[stillp]

Here's a better price on that Kewtech tester: http://www.amazon.co.uk/Kewtech-KT1...4292&sr=1-87&keywords=two-pole+voltage+tester

 

[aliasx51]

Thanks @stillp.

Final question: @flameport I am going to follow your suggestion to replace the 2 core flex with 3 core flex. If I am only connecting it between the rose above the ceiling and the rose below, can I use standard 3 amp / 720w flex or do I need higher-rated non-flexible wiring? It is only connecting to a decorative pendant lamp.

Thanks