dennis@home wrote:

"John Rumm" wrote in message
et...
dennis@home wrote:

I am one of those that doesn't think taps should be earth bonded BTW.

No such thing as "earth bonding"

Well you can argue about the term if you want, I am sure someone will
join in if you want.

The difficulty with the term (aside from it having no real meaning) is
that is introduces confusion. Earthing and equipotential bonding are two
unrelated concepts that reduce shock hazards in different ways.

If there isn't a path to earth its much harder to get a fatal shock
than if the plumber provides a low impedance earth.

ISTM you are misinterpreting the purpose of equipotential bonding:

No I just don't like earths when there is a small chance of getting a
shock because of them.

Again, who mentioned earths? There is no requirement for supplementary
bonding to be earthed.

Say a towel rail becomes live..
this indicates that there is a fault in the towel rail and that the case
*is not* connected to earth or the fuse would blow.

Indeed. The (presumably electric in this case) towel rail's heating
element should be earthed to ensure the supply is disconnected in the
event of a fault.

Now all the other stuff like pipes are connected to earth and you get a
300V+ potential between them.. nasty shock.

Which is where the equipotential zone comes into play - eliminating (or
at least reducing to a safe level) any potential difference should the
fault not be cleared by other means.

Of course if there were actual physical earth points on the towel
radiator rather than just the earth in the flex you might have a second
earth to connect to the pipes but that's not likely as the fuse hasn't
blown.

If the pipes are capable of introducing a potential into the zone, they
should also be bonded.



--
Cheers,

John.

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