Earth wire problem for ceiling light

[triplewhammy]

Hi All,
Have justed bought a nice new ceiling light (five arm halogen type) for the bedroom.
Took the ceiling rose to bits and descovered only two wires (Red and Black) going into the old fitting.
The new light light has to be earthed and hence the problem... no earth wire is present.
How do i go about earthing this fitting?
Any help would be very much appreciated.
Thanks in anticipation
Triplewhammy.

[buildersmate]

Sorry, but I don't reckon its safe to attempt to do this. Unearthed lighting circuits must have dangling pendents that require no earth or be double-insulated.

[triplewhammy]

Thanks Buildersmate,
I take your advise wisely. i did just have a look at a metal fitting downstairs which has been earthed. I can see the earth wire to the fitting but without taking up the carpets and boards upstairs I cannot see where this runs to!
Is this metal fitting downstairs safe in your opinion?

[theonlyone]

Get an electrical guy in , a real one with the credentials .
Always better safe than sorry .

[terence7556]

if the red/black cables have a grey outer sheath the bare earth conductor may be present, just snipped off.if the cable is not clipped to the nearest joist, try pulling it and expose the earth to fit a single connector block to make a connection to earth your light fitting, which i presume is metal.
if the above is not within your normal range of work call in a spark and be safe not sorry

[buildersmate]

I suspect you have a lighting wiring system put together with no earth - nothing wrong with that, unless you want to fit the sort of metal-cased lighting unit you have bought.
Its impossible to tell if the earlier installation is safe without the quality of the earth being tested. This needs an electrician with an appropriate meter.
Just to emphasise what the risk is, albeit probably small. Iin a event of a fault condition where the insulation inside broke down, the wiring inside could touch the outside casing. If it is earthed properly as it should be, the current flows back to earth by this path, blowing the fuse/breaker in the process and injuring no-one. If the earth is not good enough this might not happen making the outside casing live.

[Broadie451]

Since the "light fitting" is to be installed in a bedroom the chances are that the ceiling rose has been fed from a juction box probably a couple of meters away in the loft space.
I guess the best approach for you would be Isolate the electrical supply and get into the loft space with a flash light and locate the bedroom light fitting and trace the cable back to the junction box (it will probably be a round dark brown one with a slotted screw in the centre). Remove the cover and check for the earth conductor in the junction box. The earth conductor may have a green and yellow sleeve on it, or it may be exposed depending on when your house was re-wired.
If the is an earth cable present in the junction box you may have one of two options 1, check for any slack in the cable (perhaps re-routing slightly) then as mentioned before stripping the cable back at the point where it passes throught the ceiling and using the earth terminal. 2, replace the cable from the junction box for a type with an earth conductor of the same size as the cable installed in the rest of the wiring scheme ie if it was 1mm T+E then it should be 1mm cable or if it was 1.5mmT+E then it should be 1.5mm cable. By changing the cable this is classed as "minor works" and an electrical test certificate needs to be producted by a competant person (ie a part P registered electrician.)
I dunno what Builders mate would think of this but it may be prudent at this point to put a block of wood fixed between two joists where the light fitting is located so when you do get round to fitting the light you have a solid nechanical fixing point for the light.
I think I need to go for a rest now

[triplewhammy]

Hello All,
Firstly thanks very much for all the useful advise and solutions. I will arm myself with the torch and explore the loft space at the weekend and see what the junction box situation is.
If I'm able to do the wiring if ness after investigation I do know a sparkie who is qualified from down the street so getting the work signed of shouldn't be too much of a problem. (especially as his dad wants my help in redesiging his bathroom as i have)
Again fellas, really appreciate all the words of wisdom and your time and effort. Feel free to continue educating me when the fingers recover from the typing ache!!
Thanks
Triplewhammy.