In message ,
Adrian Simpson wrote:

A quick question on bathroom earth bonding if I may.

I'm in the process of refitting the bathroom, and all being well will
replace the bath this week. Originally the plumbing was all in copper,
and there is a steel bath. The plumbing is being replaced with plastic
(*), and the new bath is acrylic. Since there is there is very little
in the way of metal, do I have to bond it.

(*) the shower will have metal plumbing where visible (plastic where
not), but is driven from the boiler (i.e. is non-electric).

If everything is plastic then there's not usually a requirement to bond
radiators, taps and the like, however short lengths of plastic do not
count as the water might be conductive enough to "bridge" the gap -
there was a discussion on here about that a few months ago, but I can't
remember what length of plastic before metal was determined to be
"safe", something more than a couple of feet IIRC.

It *is* a requirement to supplementary bond the protective conductors of
electrical equipment within the zones, at least as far as the cord
outlet - where something like a heater is supplied through a cord.

See the On Site Guide Figures 4d and 4e, pages 30 and 31. Paragraph 4.7
on p26 is relevant and, assuming you do not have an OSG to hand here it
is:

"Supplementary bonding is not required to metal parts supplied by
plastic pipes, such as metal hot and cold water taps supplied from
plastic pipes. A metal bath not connected to extraneous-conductive parts
(such as structural steelwork) with plastic hot and cold water pipes and
plastic waste pipes does not require supplementary bonding.
Supplementary bonding in a bathroom or shower room will still be
required between the protective conductors of circuits supplying Class
I and Class II equipment in the zones e.g. heaters, showers and
accessible luminaires, see Figure 4e."

HTH

Hwyl!

M.

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Martin Angove: http://www.tridwr.demon.co.uk/
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