Earthing problem

[Farmer Giles]

A family member has just moved to another house (a bungalow). An electrical safety report states that there is no earth to the lighting circuit. I have removed a couple of light switches, and there is no earth conductor to either of them - I haven't checked things in the loft. Getting an earth cable into the loft to the individual light fittings is no great problem, but getting one to the switches looks to be physically impossible - short of chasing a new channel in the walls. As the light switches are plastic, it seems to me that the only possible hazard arises from the screws that attach them to the metal boxes in the wall. Does anyone know if replacing all the switches with 'screwless' ones - as well as, of course, running an earth conductor to the light fittings themselves, via the loft - would comply with the regulations?

[cj]

Hi No shortcuts with mains electricity I'm afraid the earth is for a reason.(eg you are moving a new table into the house as it passes end on through a doorway it smashes the light switch crushing the live feed against the metal back box ,unaware you bringing up the rear rub against the now exposed metal box SHOCKING.) My advise FWIW is have a complete electrical survey done on the property by an approved NICEIC contractor as if the lighting has no earth the power may be only spurs not ring mains ,,,,,,and so it goes on. Sorry to be a killjoy but after 35yrs in the game I have seen some death traps waiting to spring on newly acquired property owners. IIR a sold property these days should have an electrical safety cert' as part of the sale?? other on group may be up to date on this.

[ARWadsworth]

Very unlikely and also very unlikely to kill anyone.

The OPs relative has had an electrical report done. It says that there is no cpc on the lighting circuits.

Even if the electrical report says that the electrics are a death trap it does not stop someone buying that house.

Adam

[ARWadsworth]

It is probably time to bite the bullet and rewire the lights. Do the switch drops room by room if needed.

However, using class II fittings and switches will help make things safer.

probably gives you most of the info you want.

Adam

[Woody]

One question should occur - do any of the light fittings need an earth, i.e. any metal fittings or fluorescents? If not and they are only fed on two core, why worry?

[Farmer Giles]

Thanks for that, Adam. A new CU has been fitted at the property since the purchase, with a 30mA RCD - it was when this was fitted that the electrician checked the rest of the installation and discovered that there was no cpc to the lighting circuit. All the light fittings are class II (but I'll run a cpc to them anyway) - as I said in my opening post, the only problem is with the switches. If I replace all the metal switch boxes with plastic ones, and put a warning notice on the CU to that effect, would the installation then be considered to be up to scratch?

[Farmer Giles]

You are not being a 'killjoy' - just patronising and self-important! Actually, I spent a deal more than 35 years in the 'game' - that is, the electrical business - albeit not domestic electrical installations, but something a deal more complex. I asked the question because I'm not up to date on present regulations - not because I wanted a lecture on safety, I'm all too aware of the need for that.

[ARWadsworth]

It would be safer if you did change the back boxes but it is not that essential. I wonder if you can still get the plastic screws (I know BOLTS) that they used to use some years ago and keep the metal back boxes?

Cheers

Adam

[Tinkerer]

Are they bolts or machine screws?

[Martin]

Steady on - that's unwarranted. There is no reason to suppose cj knows your background, and with comments like "my advice FWIW", "IIRC", and "others may be up to date" he couldn't have been much more gentle and modest.

See current thread on "lightbulb not switching off" if you need persuading that not everyone here has had "35 years on the game".

Re. your problem, it might be worth looking closely at the possibility of using existing cable drops to pull through new T+E. I've recently done similar, to replace twin with 3-core for 2 way. Was surprisingly straightforward.

[Farmer Giles]

Ok, fair enough - and thanks. Perhaps I did bite a bit too much. Having said that, there is a tendency on here for some people to respond in a world-weary, patronising way. Just because you don't know anything about someone else's background, that is no justification for making unwarranted assumptions, or adopting a patronising tone.

BTW (and on a lighter note), I do hope that very few here have had 35 years

*on* the game - I wouldn't want to move in those kind of circles!

[Farmer Giles]

Yes, I have only ever heard them called screws.

Note for Adam: The plastic screw is a good idea - any idea who might stock them?

[Andy Champ]

FWIW I haven't had 35 years on the game, _whatever_ game it is. I only commented on the lightbulb one to try and stop the guy killing himself. but WTF. It's only evolution in action :/

Andy

[ARWadsworth]

Machine screws, but I have known then to be called boltd.

No idea where to get the plastic ones from. I will have a look over the weekend.

How do you intend to swap the backbox without damaging the plaster?

Cheers

Adam

[Farmer Giles]

>

I think by gently cutting around them they should come out alright. Although I might try to pull some new 1mm twin and earth through instead - as suggested by Martin.

[cj]

I was not being patronising or self important just trying to be of help to someone I have never met who asked a question on a DIY news site.Not a technical bulletin board for electrical engineers. My recommendations were based on your post which stated 'An electrical safety report' .This was not specific and having seem many so called reports wrongly ( i accept) assumed you may not have had a legitimate document. I respect Adam's comments but stand by my post as I did not mention death just the possibility of a shock .(There have been numerous post on this NG in the past regarding shocks from newly plastered or papered walls where switches were left loose and my example,however remote, is plausible.) My intent was to warn you of the possible dangers in simple terms and provide a possible solution.

So at the risk of again being insulted I offer this, Check the switch boxes to see if the cabling is in capping or tube (it should be). If so rewiring can sometimes be achieved by using the existing cable as a draw wire. If loft access is easy you can sometimes see the capping protruding from the ceiling below. Nylon screws 3.5mm are a rarity (you can buy them but they come in 1000 for £22 aprox' bags RS Components IIR) Try a diy store in the Plumbing isle look for bathroom fan switch bolts or your local hobby/model shop may stock them.(used on some nitro cars) also used on door entry systems and nurse call wall plates.

[PeterC]

Check to see if the existing cable has steel capping. We could pull through new cable, but found out with the first piece that there was a semi-automatic wire stripper in the wall!

[ARWadsworth]

Is see RS do bags of 100 nylon screws for about 5 or 6 quid. Thanks for the info as I do need some.

I would suggest nylon screws are the way forward for the OP if wants to make the lightswitch safer. Even a bag of a 1000 screws at £22 is cheaper and easier than changing the back boxes. I have often found that changing the old wooden back boxes to metal ones cannot always be done without causing some damage to the surrounding area and needs a finger plate surround to cover the damage.

Do you remember the old metal back boxes with the plastic lugs? Mid 1960s installs at a guess..

A rewire of the switch drops on a room by room basis as they are decorated is also recommended.

Adam

[cj]

[ARWadsworth]

Good point. Although is was 4BA

Note to Farmer Giles

You may find that your screws are not 3.5M but 4BA.

Adam