On Sun, 17 Oct 2004 20:41:48 +0100, Aardvark
wrote:

Should I get an earth strap and earth these lights to the incoming
water supply pipe, or do the regulations / best practice say I should
do something else.

Best way is to find the most convenient socket which has an earth to
it and bond it there.

Relying on water pipes is not ideal because however unlikely it may
seem a plumber (or whoever) could disconnect the pipe and thus break
the bond.

Using the incoming water mains as the bonding (earthing) point went
out a while back. Bonding arrangements using pipework is used for
something called equipotential bonding - to keep all the pipework at
the same potential (voltage if you will), and that might not
necessarily be ground.

The ideal situation would be to run the earth back to the consumer
unit. If you do run an earth wire any distance it's best to make it a
fair size (4mm or better).

Andrew