As often asked, to what extent do we have to try to anticipate what other people may do in the future? Let's face it, after that plumber's visit, bonding that had been connected 'at the point of entry' may have magically become 'disconnected'! In both cases, all we can do is to put warning labels around the place, and hope that the plumber can read!
That's true but the only reason I can see for stating 'point of entry'. Nowhere is it said that bonding may be applied elsewhere - other than 'where practicable', would that cover what we are saying?.
Isn't is all down to words/semantics? Say one has a water supply pipe which is bonded to MET (with G/Y) 10m from the point of entry. If one chooses to define, say, the first 9.6m of the pipe (starting from the MET end) as a 'bonding conductor' (which is seemingly allowed), then the incoming supply pipe is being 'bonded' 400mm from the point of entry, just as if it would be if there were a 9.6m length of 10mm² G/Y, isnt' it?
In practice, of course, the main issue may be well not relate so much to subsequent plumbers' visits as electricians' visits. What proportion of electricians undertaking an EICR do you think would be happy with bonding that was connected to the pipe distant from the point of entry?
Not many but that doesn't make something wrong.
Not wrong, no, but that situation would create a major nuisance ... as you go on to say...
At the least, one would probably have to stick an 'explanatory note' to the CU, MET and/or point of connection of the (G/Y) bonding conductor - otherwise I suspect that there is a very high chance that it would get 'coded'!
It would.
Do you consider what you are suggesting is that the water pipe is satisfactorily bonded or that the pipe is its own bonding conductor? Is there a difference?
I don't see any difference.
It may be splitting hairs but is it considered that the bonding should be applied at the origin or cause of any pd?
Sure, and that obviously makes sense. However, as above, if one considers most of the internal pipe to be a bonding conductor then one
is bonding the incoming pipe 'at its origin', isn't one? As you go on to say
... If so, then it must be considered to be its own bonding conductor.
This is not allowed for a gas pipe ...
It isn't - presumably because of concerns about potentially high currents being carried by a pipe containing gas. However, if you accept the arguments above, there is presumably no reason why a water pipe could not be used as (most of) the 'bonding conductor' for an incoming gas pipe.
Let's face it, if one really wanted to be silly (but to make the point) one could run a 'bonding conductor' consisting of a length of copper piping (with electrical continuity throughout) from the MET to to the incoming water pipe at the point of entry, couldn't one?
If you mean purposely laid parallel to the water pipe then, yes.
Yes, that's precisely what I meant. I don't think the regs actually insist that a protective conductor be identified by G/Y markings (or, indeed, even insist that it is insulated at all).
In common sense/safety terms, I suppose what this all comes down to is the question of how likely one feels it is that (given some warning labels) an internal water supply pipe would be interfered with such as to destroy the electrical continuity (and how much more likely one feels that is than a plumber, or whoever, disconnecting or damaging a G/Y bonding conductor).
Kind Regards, John