shaver light wiring

[raytay]

When wiring a shaver light incorporating a shaver socket in a bathroom above a washbasin and mirror must it be connected into the bathroom supplementary equipotential bonding?
The shaver light is described in the TLC catalogue as of class 2 construction and has 20va safety isolating transformer.
The shaver light would be mounted >600 mm above the sink in what I believe is Zone 3.
I would very much appreciate any advice.

 

[oharaf]

Connecting through the ceiling rose earth is enough, you do not need to add supp bond

 

[raytay]

Thanks for your reply Oharaf. The shaver light will be fitted to an existing supply which is on the lighting circuit but inspection of the connections to the ceiling rose and pull switch did not show any seperate 4mm
bonding wire only the lighting CPC.
I think I must presume my lighting circuit is not connected to the supplementary bonding on the pipework etc.

 

[oharaf]

Raytay, All your cpc's are connected in the consumer unit on the earth bar. Here you may also find your Supplementary bonding for the bathroom and kitchen, you will also find near by the Main Equipotential bonding from your gas and water.

We do not generally connect earths cpc's from light fittings directly to supp bonding!!!

Just make sure that your fitting has an earth and is connected to an earth that is terminated at the CU


If you're not sure get a sparky

 

[mikeyd]

Oharaf,

I'm confused. I thought supplimentary bonding was required on the CPC of cables in a bathroom even if they are supplying class 2 devices (assuming 16th edition). Is this not so? And what do you mean by

We do not generally connect earths cpc's from light fittings directly to supp bonding!!!

On my electricians advice I did this in my bathroom. I took a 4mm from there to the shower and to all the pipework. Was it not necessary? He checked, tested and signed the work off and I trust his judgement

 

[raytay]

Thanks for your comments Oharaf.

I thought you might like to know that I have now obtained a copy of the On-Site Guide BS7671 : 2001 (2004). Fig 4d in this shows the shaver socket connected to the bathroom pipework. It also has a note specifying that all power and lighting points within the zones must be supplementary bonded.

I have convinced myself that my lighting circuit is not bonded and intend therefore to run a 4mm lead from the shaver supply CPC to the pipework.
This will mean my shaver supply and lighting circuit is bonded.

Incidentally the shaver light which I bought yesterday and examined is a class 2 appliance and requires only a live and neutral with no provision to anchor the CPC so I will terminate this in a choc block together with the new 4mm bond wire.

 

[mikeyd]

Phew, raytay I think you have made a wise move there.

I'm no expert but I think if you connect your 4mm bonding to the CPC at the supply end (ceiling rose/fcu) then you don't have to chase it all the way to the shaver socket. (incase you didn't know that already...)

Did you find Oharaf's suggestions confusing, or just plain wrong? I'm not an electrician, but I thought his advice was badly worded. (that's me being polite)

If any of the regulars would like to comment.....

 

[oharaf]

What the hell are you looking at the 16th Edition for!!!!!

From the 1st of June installations are to the 17th Edition, all services, unless SELV, in the Bathroom, are to be protected by a 30mA RCD.

Supplementary bonding is no longer required.

I suggest you do a little reading up and learn the difference between Main Equipotential bonding, Supplementary Equipotential Bonding and CPC's

Thes are never con-joined until they reach the MET block near the service head.

Correct you are no Electrician!!!!


I am!!!!

 

[Belboz]

oharaf,

Did you mean to post 1st JUNE??



Just to get this right, [17th] SELV no RCD requirement. Shower cable, RCD protected. But what about the shaver socket - does this come as an exemption??

Sorry but I am fitting one soon....

Cheers

 

[oharaf]

From the 1st of June installations should be done to the 17th (thou 16th is 'allowable' until the 1st of July

All circuits in bathrooms must be RCD protected, the feed for you shaver socket will have to come from somewhere, the ceiling rose or spur from radial / ring.

So these circuits will require RCD protection.

Remember that SELV (Seperated Extra Low Voltage) refers to the transformer in the shaver socket.

Seperated - The transformer

Extra Low Voltage - less than120v a.c.

However the transformer will be supplied from a LV supply

 

[mikeyd]

I suggest you do a little reading up and learn the difference between Main Equipotential bonding, Supplementary Equipotential Bonding and CPC's

Ok, done some reading.

....in the consumer unit on the earth bar. Here you may also find your Supplementary bonding for the bathroom...

I'm still confused though.

 

[raytay]

We seem to have a lively debate going here.
If I understand Oharaf correctly then to be up to date i should replace my lighting circuit old style over-current trip in the consumer unit with an RCD.
Am I right in thinking this will require a new consumer unit?

 

[Belboz]

Yeah, I'm a tad confused too.

My current set-up is Shaver socket wired into bathroom lighting circuit. Lighting circuit is 'normal' i.e. CPC and usual wiring. Transformer is connected and 'earthed' to that. Shower is wired into a switch and protected by its own 30mA RCD as per MIs.

I am intending to replace the shaver socket imminently.

I am now wondering whether I need to fit an RCD to the bathroom lighting circuit BEFORE wiring in the shaver socket.

However, my CU is not an old fuse type but it IS an older MCB type. Would this suffice to cover the lighting circuit [which has its own MCB] without the need for me to buy and fit an RCD for the lighting circuit??

 

[securespark]

Oharaf

PLEASE EXPLAIN YOURSELF FULLY!

What you have written suggests that supp bonds go back to the CU.

THEY DO NOT!

All supplementary bonding is doing is making simultaneously accessible metalkwork the same potential.

There is no direct link from SB conductors back to the MET.

Until Tuesday, you can work to the 16th.

Connecting through the ceiling rose earth is enough, you do not need to add supp bond

Provided that ceiling rose earth, as you call it, is supp bonded.

 

[securespark]

Raytay, All your cpc's are connected in the consumer unit on the earth bar. Here you may also find your Supplementary bonding for the bathroom and kitchen, you will also find near by the Main Equipotential bonding from your gas and water.

We do not generally connect earths cpc's from light fittings directly to supp bonding!!!

Just make sure that your fitting has an earth and is connected to an earth that is terminated at the CU

You should NOT find SB's in the CU.

SB's in a domestic kitchen disappeared when the 16th was introduced in 1991....

Connect cpc's to SB conductors. YES WE DO!!

If you're not sure get a sparky

Or at least someone who knows what they're talking about.
Disgraceful advice to post on a DIY forum.

You should be ashamed.

Edited to correct spelling mistakes.