In message ,
"Christian McArdle" wrote:

A bathroom that is piped in all plastic should not have its radiator
bonded.
This has been mentioned in many earlier threads here and is also stated
in
the IEE OSG and on NICEIC newsletters.

Could whoever argued for this last time answer this ? You convinced me to
do so last time. Thanks.

Well I argued that you definitely should NOT bond radiators, metal baths,
taps or metal window frames that would otherwise have no connection to
earth.

These items should only be bonded if they are already earthed, such as
through metal pipework or touching the structural metalwork of the building.


Yes, this is specifically pointed out in the OSG - it makes it very
clear that supplementary bonding of *isolated* metalwork is in fact more
dangerous than leaving it isolated.

What I remember we argued about was the definition of isolated. A very
short length of plastic pipe (less than about 1 meter) does not count
as due to the conductivity of the water the metal item (tap, radiator
etc) could still be said to be "earthy" and therefore should be bonded.
Above 1m or so the resistance of the water becomes sufficiently high for
the item in question to be regarded as isolated from earth.

This figure of 1 meter was IIRC calculated and reported in an IEE
newsletter, and repeated fairly recently.

Hwyl!

M.

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