Installing shaver socket from celing circuit without earth

Nikouk · 19 Jul 2007

Hello All,

I noticed when replacing the original 1968 lighting circuit in my loft (due to a strange green goo present in most of the wire/switches/light fittings-what is that?!) that the earth was redundant/not wired into the circuit.
I removed the old shaver socket wiring from the bathroom beneath, which was run from the the same lighting circuit and don't think that it was earthed either.
I now want to install a shaver socket in a wall mounted stainless steel bathroom cabinet above my basin. This will involve cutting a hole in the back of the cabinet and either sinking a box into the wall, or using a surface mounted kitchen box to accomodate the new shaver socket.
On reading the instructions, I notice that the socket says to wire up the earth from the supply, to the switch transformer, and then to the box.
SO! (sorry for long windedness) my question are these:

1)can I use a surface mounted box/pattress - if so how do I provide a run to earth in this kind of box?
2)given that it's stainless steel and I want to cut a whole in it and mount the shaver socket inside it is there a risk of making the whole cabinet live if I mount the box or sink it into the wall?
3)in order to provide an earth on the feed, do I need to run the earth all the way back to the fuse box (2 floors downstairs)?
4)what's the easiest way to solve this problem?!

Many thanks in advance to you wise and good people!
Nick

luminaire · 19 Jul 2007

Firstly, any work you do in a bathroom is notifiable unless you use a P registered electrician.

Does your bathroom already have supplementary bonding?
Are the pipes plastic or metal?

Nikouk · 19 Jul 2007

Hello Luminaire,
thanks for the reply.
I will get all my work signed off.
Forgive my ignorance, my background is plastering - what is supplementary bonding?
When you say "Are the pipes plastic or metal?", do you mean the wiring conduits? If so, I must confess I simply ran a new cable from the ceiling and plastered into the wall

Nick

JohnD · 19 Jul 2007

Nikouk said:
I will get all my work signed off.

Why do they all say that?

Chri5 · 19 Jul 2007

Nikouk said:
Forgive my ignorance, my background is plastering - what is supplementary bonding?
When you say "Are the pipes plastic or metal?", do you mean the wiring conduits? If so, I must confess I simply ran a new cable from the ceiling and plastered into the wall
Nick

Supplementary bonding is taking earths from the bathroom lighting (and any other bathroom circuit) and terminating them on to plumbing pipes, radiators and any exposed metal within the bathroom. This is done to equalise the potential and avoid risk of shock, which in a wet room area could be nasty.

I would suggest you check and terminate the earth that will be present in your renewed lighting cabling and extend this down to the shaver socket position.

That will give you the earth required for the shaver position. Now you have an earth in the bathroom area you can earth bond the steel cabinet (via a self tapping screw and a round holed earth lug maybe?) and then conside the earths for bonding the rest of the bathroom.

luminaire · 19 Jul 2007

Nikouk said:
what is supplementary bonding?

have a look here

http://www.ultimatehandyman.co.uk/earthing_supplementary.htm

Too quick for me!

JohnD · 19 Jul 2007

And you mustn't use a metal switch (or socket or light fitting) without an earth. The older houses sometimes had un-earthed lighting circuits, on the grounds that the fittings were plastic, and up on the ceiling where you couldn't touch them to get a shock.

If you have a house with an un-earthed lighting circuit, then the circuit is probably 40 years old or so, and ripe for replacement.

The risks of electrocution from inexpert work are particularly high in bathrooms ue to the presence of water and the absence of insulating shoes and clothes..

Nikouk · 19 Jul 2007

Thanks for the reply Chri5,

When you say "I would suggest you check and terminate the earth that will be present in your renewed lighting cabling and extend this down to the shaver socket position."
I'm a bit confused. The new piece of cable, which replaced the old one for the shaver socket but in a different location in the bathroom, has an earth wire but is disconnected from the ceiling circuit in the celing. Do i need to earth at the ceiling end (if so how would you suggest?) as well as attaching it to the pipes under the basin?

"That will give you the earth required for the shaver position. Now you have an earth in the bathroom area you can earth bond the steel cabinet (via a self tapping screw and a round holed earth lug maybe?) and then conside the earths for bonding the rest of the bathroom."
So, I can safely mount the socket in a plastic surface mounted box in the cabinet, provided I earth it to the pipework, and also to be safe earth the cabinet by fixing a screw into the wall through the cabinet?

There are earth straps between all the pipes beneath my boiler, on the ground floor - the bathroom is on the second floor.

Many thanks for your help,
Nick

Nikouk · 19 Jul 2007

Hello JohnD,
thanks for your reply. How do I earth my antique lighting circuit then?
Nick

JohnD · 19 Jul 2007

old one in skip.

New one in house.

sparky23 · 19 Jul 2007

Nikouk take it from me get a competent electrician in to take a look at it. it sounds to me like you need the whole lighting circuit re wired.

securespark · 19 Jul 2007

You don't need to link every pipe with a run of cable.

It is permissible to use the pipework as the supplementary bonding conductor itself.

Nikouk · 20 Jul 2007

Thanks to you helpful guys for your responses.

I am a competent DIYer and have done a fair amount of re-wiring in this property, simply being told to get a sparky in to rip out and replace isn't really what this site is about is it? If I had that sort of money I wouldn't be on this site looking for direction, I would simply get someone in.

Can anyone therefore answer my question in simple lay terms:

I understand that I need to run the earth to the pipework at the shaver socket end of my cable. However, what do I do with the ceiling end, can I attach this to a pipe also, or does it need to be run to a plug socket and earthed there?

Also, another unrelated question, is have any of you guys seen the thick, sticky green goo that seems to be present in all my house's wiring? It seems to be some kind of verdigree/copper reaction - I've found it at the bathroom light fitting I replaced and at the wall switches for the lighting circuits and where I replaced some of the wiring it was present in the entire cable...?

Yours gratefully in advance,
Nick

JohnD · 20 Jul 2007

I still reckon you need to pull out the old wiring (and no doubt many of the old ceiling roses, pendants drops, junction boxes

and switches if equally old), and rerun with new. This will include the circuit being fully earthed back to the consumer unit, and subsequent supplementary bonding in the bathroom. I don't see how you can supplementary-bond to a lighting circuit that isn't earthed.

If you are competent to do it yourself, and do so to a proper standard including testing and noification, do that, though you may find it more trouble and expense than getting a professional in.

see also
//www.diynot.com/search/forum....t=0&author=&search=Search+Forum&mode=advanced

You must NOT NOT NOT NOT NOT use a metal shaver socket or light switch until the circuit has been rerun and earthed.

equitum · 20 Jul 2007

"Green Goo" is most prevalent in pvc cables manufactured between 1965 and 1971. It is degraded di-isoctyl phthalate - a chemical reaction between the insulation and the copper.

It does not affect the saftey or integrity of the installation other than maybe functionality of switches, and looks a mess. Its non toxic.
(summary from extract from NICEIC publication)

Although a competent diyer, it sounds, in my opinion that you are unsure as to what you are doing and whilst forum advice can help I would also recommend you get a registered competent person in, as I suspect you have not already informed the LABC of the work.

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Installing shaver socket from celing circuit without earth

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