Earthing Lead Pipes

[Desie]

Quickie I hope.

Full re-piping of a house in plastic except the netre or so coming into the property on lead leading to a metal stop cock.

Does it need bonding, if so where?

 

[securespark]

Th regulations state that MEBonding should be carried out within 600mm of the stopcock (on the consumer's side of the cock). If that pipe is plastic, it should be bonded where the plastic joins to copper. If the whole water pipe installation is plastic, there is no requirement for MEB to water.

 

[plugwash]

the lead pipe is touchable inside the house and connects to substantial undergound metalwork so imo it needs bonding.

is there a short peice of copper before the stopcock (soldering copper into the end of a lead pipe is one way its sometimes jointed to modern stuff)? if so i'd put a bonding clamp on that. Its not a good idea to use bonding clamps on lead pipe and soldering would require draining the pipe which would also be hard.

 

[Spark123]

I'd recommend replacing the lead in anycase owing to the risk from lead poisoning.

 

[securespark]

The pipework out to the street is already grounded by virtue of the fact it is buried in the ground! As electricians, we are not interested in this side of the stopcock, but the consumer's side. Otherwise, the regulations would recommend bonding the other side.

 

[Desie]

Hi securespark

Looks like we agree on this one!!



Incidental question......... if this was a rented property would it fail the PIR by way of having no bonding and no visible signs that the total installation is plastic?

 

[plugwash]

The pipework out to the street is already grounded by virtue of the fact it is buried in the ground!

and thats the problem, the whole point of main bonding is to tie anything that is attatched to local ground to mains ground as well (since mains ground especially during faults may not be the same potential as local ground)

the stopcock is clearly touchable metalwork inside the equpotential zone and tied to something that can bring in a potential so it clearly needs bonding.

 

[Spark123]

But it is the fact that the metal water pipe can introduce true earth potential into the equipotential zone is imho the reason it is required to be main equipotentially bonded. It has to be an extraneous conductive part doesn't it?

 

[plugwash]

http://www.niceic.org.uk/downloads/E169-9.pdf#search=""extraneous conductive part""

clearly the stopcock is touchable
clearly the stopcock is liable to be at local earth (rather than installation earth) potential because its attatched to a load of burried lead pipework
potentially the stopcock could easilly be touched at the same time as say a metal cased kitchen appliance.

so at least by my reading of that document its an ECP and needs bonding.

anyone like to argue with that analysis?

 

[securespark]

You can't argue with the fact that a qualified electrician never bonds to the "wrong" side of the stopcock.

Would you like to argue with that analysis?

 

[securespark]

potentially the stopcock could easilly be touched at the same time as say a metal cased kitchen appliance.

Potentially....easily... those words don't marry, do they?

Not if the stopcock is in the hall, or a cupboard. Jeez, this is getting silly!

 

[plugwash]

obviously if its far away from anything thats likely to get connected to the installation earth this isn't an issue.

i'd disagree about a kitchen cupboard making it unlikely to touch a metal cased kitchen appliance at the same time though, especially as the cupboard with the water coming in is liable to end up also being the cupboard thats next to the washing machine/dishwasher.