Nigel Molesworth wrote:

On Fri, 10 Mar 2006 20:56:59 +0000, John Rumm wrote:


So how do you guarentee that the fault causing your cold tap to sit at
240V is a result of contact with an RCD protected circuit then?


No other way for it to happen.

You sure?

What about a lighting circuit? Or is that on a RCD as well (which in
itself may represent a significant injury risk)?

What about all your neighbours circuits - you sure they are all RCD
protected? Or are you sure there is no stray earth connection to a
neighbouring property via a shared water or gas main or even a bit of
structural steel work?

What about when a daft JCB driver puts a bucket through the supply and
causes a fault to earth on the supply side of your RCD, still happy you
will be safe?

The technical content of BS7671 was not written by a bunch of guys with
nothing better to do, who just get out of bed one day and thought of
jolly ways to keep the electrical contracting trade busy. There is
generally very solid reasoning to back up these concepts, but some of
this stuff is quite subtle.


--
Cheers,

John.

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