Lighting circuit with no earth and metal light fittings

[0netrack]

Hi all,

I've just moved in to an old Cornish property, the electrics are in an ok state for the most part but the lighting is only twin core with no earth. This was raised on the recent electrical inspection as C2 - requiring urgent attention. I was hoping to delay any electrical work, the house was occupied by a family when we bought it after all, but I suspect I will have to reconsider based on what I've been discovering. Anything I do I'm doing with the entire system shut down, as I don't trust it just to have the light fuse disconnected at the consumer unit.

As I've been removing light fittings to replace them, I've found that there are no ceiling roses, some are just two wires wound together with red insulation tape, while others are just choc block with no insulation tape and all the wires crammed in there for the switch and loop system.

To make matters even worse, a lot of the original lights are metal, including the kitchen light which is on a relatively low ceiling.

When I opened the two gang switch in the lounge, I found that it had been wired with a single three core cable + earth (but wired as though it was two cables, to control the ceiling light and wall lights separately, re-using the same live red wire between the two points). When I looked at the junction box under the floorboards above the lounge, I found that the earth from this switch doesn't appear to go anywhere. The switch is a metal box with a standard square plastic faceplate (so with two metal screws facing out), so now I'm worried that there is a risk from even using this light switch if it is not really earthed (and this is a room with a metal light). I am going to replace this immediately with a plastic box, regardless of what else I do.

So based on the above, I would assume that I need to replace all lights and light switches with plastic fittings and add in ceiling roses until I can get the electrics changed?

Any advice (even 'call an electrician') would be appreciated.

Dan

 

[PrenticeBoyofDerry]

It is not uncommon to come across installations where the lighting circuit has not been correctly earthed. Back in the day it was not done.
As you are aware that having metallic fittings attached to these circuits, is a potential hazard and must be resolved.

A little further investigation may reveal that the CPC (AKA earth cable), has been cut back/snipped off at the accessory and there maybe evidence of it being present within the cable's sheath.
If so, it could be possible to introduce the CPC by terminating the CPC, this may involve extending the conductor, but this will need doing at all terminals at switch plates, fittings and junction boxes, then confirming via continuity tests.

Other than that you would be advised to remove all metallic fitting or introduce a CPC.
If introducing a CPC, the logical step would be to re-wire the lighting circuits.

The use of choc blocks is permitted but they must be within enclosures, and the joint easily accessible. Switch boxes and light fitting would be considered as enclosures, popped up in the ceiling void would not.

 

[ban-all-sheds]

I would certainly replace any metal switches.

Recessed metal boxes are not easily replaced with plastic ones, what you can do about the screws is either buy switches where they are covered by little plugs, or use nylon screws.

As for the lights, now that you are aware of the problem, then any which are only likely to be touched if you're changing a bulb, just make sure you isolate them first.

And get an electrician to check everything out asap.