Earthing my water supply

[ColJack]

firstly, correct or incorrect is in the eye of the beholder.
secondly I'm at my mothers so don't have access to me regs book but I'm pretty sure that this is an accurate definition..

An Extraneous Conductive Part is a metal part that is not part of, but in proximity to the electrical installation and is liable to introduce earth potential.

please note the words in italics.

now..

there are a few words in your post that I would like to point out..

Outlined below is the relevant section from the Electricians guide to the Building Regulations:

it's a guide to, not a definitive cast iron explanation of the regs..

"There is NO requirement to main bond an incoming service where both the incoming supply pipe and the pipework within the installation are both of plastic. Where there is a plastic incoming service and a metal installation within the premises , main bonding may be needed and in such cases the main boding conductors should be connected on the customers side of any meter, main stop cock or insulating insert."

that's MAY be needed.. if it tests as extraneous supply ( maybe it's only 500mm of plastic because the entry point moved etc.. ) then it needs main bonding, if it's NOT extraneous then it doesn't.
this is not to say that it doesn't need supplimentary bonding in areas such as bathrooms to meet the requirements of other regulations..

while there is no harm in putting a 10mm earth and a clamp on the copper, it's not absolutely needed.. you couldn't automatically mark it down on a PIR for not having one for example..

take as an example the pipes for your rdiators, do you run a main bond back to the MET for those?
you don't even have to cross bond them at the boiler for electrical regs ( but the gassafe guys seem to like to do it so it might be in their regs to do so )..

 

[ban-all-sheds]

true, but I've much more chance to come into contact with the metal door frames than I do the pipework that it under the floors, and behind kitchen units don't i?

CH radiators?

 

[riveralt]

while there is no harm in putting a 10mm earth and a clamp on the copper, it's not absolutely needed.. you couldn't automatically mark it down on a PIR for not having one for example.. .

Not sure why your dancing on the point of a pin on this Coljack.

I am fully aware of 'mays' and 'guide' issues that rear there head whenever the building regulations and the Wiring Regulations are raised. That is why I quoted what I quoted.

Personally, when conducting a PIR I would Code 2 (requires improvement) if it didn't have an adequate fault protection viz 'presence of protective bonding conductors' - as per the Electricity Council guidance on PIR's.

Professionally, I would be challenged by those who inspect my work if I failed to ensure that the main protective bonding conductors were in place and met the regulations in terms of location, size of cable and bonding method. Consequently, on any installation I am involved in as a minimum both water and gas will have main protective bonding - no ifs, buts or may (be).

The OP has stated that he/she is in education mode - I have pointed out what the regulations/guidance state and what I believe is the correct course of action. Whether the OP takes that advice is up to them!

 

[ColJack]

true, but I've much more chance to come into contact with the metal door frames than I do the pipework that it under the floors, and behind kitchen units don't i?

CH radiators?

we're talking about cold water mains, and while the odds are in favour of an electrical connection via the boiler, it's not absolute that it is so.. the use of fibre washers and ptfe tape may mean that the pipes are electrically seperate ( which is why they insist on cross bonding at the boilers maybe? )

oh and the house with the metal door frames and patio doors has hot air central heating.