earth cross bonding in bathrooms & kitchens

[Lextoy]

Does anybody know the regs? I have been told that all light fittings in bathrooms and kitchens should be cross bonded. Is this correct when a light fitting is double insulated

[baldelectrician]

no additional bonding is required in a standard kitchen (ie one without electric waste disposals and similar items)

Bathroom bonding is required and important.

Search on the forum for the spefics

[Lextoy]

Thanks. I am well aware that the metal items have to be cross bonded within the bathroom. My specific question was: do all light fittings have to be cross bonded even though they are double insulated?

[Har_vey]

The lighting circuit coming into the bathroom has to be bonded to any other electrical circuit in the bathroom. So it's not just a case of ignoring it if the fitting happens to be double insulated. You obviously don't bond to a fitting which is double insulated, but someone might change the fitting at some point.

[Lextoy]

On this occasion I am installing GU10 recessed double insulated spot lights. These fittings have no terminal for connecting an earth wire to them. As far as I am aware the regulations for double insulated light fittings state that no earth wire must be fitted. So what now happens with cross bonding these lights in bathrooms? Should I now go against the regulation and connect an earth wire when in fact it says I shouldn't. This installation will have to be certified on completion.

[Har_vey]

presumably if they don't have to be earthed due to being double insualted, then you just make sure that the lighting circuit itself is covered. Then you just have to watch that the lights are ok to be positioned in the bathroom re the zones?

[ban-all-sheds]

Lextoy wrote:

Thanks. I am well aware that the metal items have to be cross bonded within the bathroom. My specific question was: do all light fittings have to be cross bonded even though they are double insulated?

1) It's not as simple as all metal items - you should only apply supplementary equipotential bonding to extraneous-conductive-parts, not simply anything metal. This is crucial, as bonding something which is not an e-c-p makes things less safe, not more.

2) It's the cpcs of circuits supplying appliances that are bonded, not the appliances themselves (although with Class I appliances the earth terminal may be a convenient place to access the cpc). If you've got Class II luminaires then you'll need to find somewhere else to connect to the lighting cpc.

3) It isn't only lighting circuits that are involved.

Regulation 601-04-01:

Local supplementary equipotential bonding complying with Regulation 547-03 shall be provided connecting together the terminal of the protective conductor of each circuit supplying Class I and Class II equipment in zones 1, 2 or 3, and extraneous-conductive-parts in these zones including the following:

(i) metallic pipes supplying services and metallic waste pipes (eg water, gas)

(ii) metallic central heating pipes and air conditioning systems

(iii) accessible metallic structural parts of the building; (metallic door architraves, window frames and similar parts are not considered to be extraneous-conductive-parts unless they are connected to metallic structural parts of the building)

(iv) metallic baths and metallic shower basins.

The supplementary bonding may be provided in close proximity to the location

See the following for useful information:

Bathrooms

Definition of "extraneous-conductive-part"

Earthing v bonding