"Owain" wrote in message
...
jon wrote:
Ok, this is probably a very stupid question, so apologies, but..
The is no earthing in my bathroom, i.e. the radiator, hot and cold pipes
to bath, basin, toilet, also the plugs and overflows. The only thing that
is earthed is the 8.5kw shower.
Anyway looking on t'internet it appears that I need to cross bond all of
the above items with earth wire and then connect to the earth terminal in
the shower isolating pull cord switch.
Ok, here is the stupid question, currently (pardon the pun), there is no
danger of me getting an electric shock, as I never do, and never will
take any electrical item into the bathroom, and secondly the electric
shower has been connected correctly. So if I was to carry out the
earthing work as per regs, then wouldn't I be increasing the chances of
an electric shock.

Not in normal circumstances.

Basically I have a irrational fear that somehow the earth lead will
someday work its way out of the terminal in the bathroom isolater switch
and then make contact to the live terminal, and now suddenly all the
earthed stuff is live.

Which would not give you an electric shock. To get an electric shock there
has to be a voltage (*potential difference*) between two points. The
bonding is not there to earth the bathroom, it is there to join every
conductive part entering the bathroom to form an equipotential zone. This
equipotential bonding prevents the difference in potential (voltage)
rising to a dangerous level.

To take an admittedly extreme and theoretical example, and I do not
recommend this in practice, you should stick a 240V live cable in your
mouth while standing in the bath and not feel the slightest tingle
PROVIDED that the bath (and thus you) was also at 240V through the
equipotential bodning.

Cheers, the mother-in-law visits on the weekend, i'll test your theory then.

Jon