TT Earthing via a well

[bernardgreen]

A property with TT supply also has a well under the cellar floor. Lead pipe 2 -3 inch diameter from well feeds old hand pump in garden by kitchen window. Goes through floor about 6 foot from well and then enters well about 2 feet below water line.

Would the lead pipe which is exposed in the cellar need to be bonded and could it be used as ( or considered as ) an earth rod ( in parallel with a "normal" earth rod ).

Plans are to convert to PME when major renovations are started before next summer.

 

[Lectrician]

You could use it as an earth rod as long as you are the owner of the pipe (most likely), and you take precautions against its removal. Subject to neccessary tests of course.

It would need a main equipotential bond in any case.

It may still be prudent to sink a rod in anyway, as this covers you in case the pipe was every taken out of service and the earthing lost after you have left.

 

[plugwash]

My understanding it if it is exposed inside and runs into the ground then it should definately be bonded but you shouldn't rely on it as a source of earthing (that is the conventional rod should be good enough to provide an adequate earh on its own) because it could end up being removed at any time.

 

[securespark]

You could use it as an earth rod as long as you are the owner of the pipe (most likely), and you take precautions against its removal. Subject to neccessary tests of course.

Isn't that only in the 17th??

 

[Lectrician]

In fact, I may change my mind or judgment....

I just took a scan, and it is the lead sheath of a cable you could use as an electrode, and not a pipe - A water or gas service pipe is not permissible, however, what is the definition of a service pipe as delcared in the regs?

 

[Pensdown]

My take on the definition would be a pipe with a primary function of bringing a non electrical service into/out off the property.

So in Bernards case although bonding the pipe will probably help lower the overall Zs values it's primary function is to bring water from the well. It may be have to be modified, cut or removed in connection with it's primary function so Ze should still be measured in the normal way with it disconnected.

However, if the well was taken out of service then the pipe is no longer a "service pipe" so IMO it could be used as an earth electrode but it would need to be very clearly labelled.