Main Earth from Extraneous Conductive Part

[ultinator]

I was at an old maisonette the other day, and everything was old wiring, 3036's etc.

Then I noticed at the CU there was no apparent main earth coming from incoming supply, and it looked as though there once had been an earth clamp around the DNO supply cable,
tried Zs from cooker s/o and nothing,
Zs from sockets at 0.8, but after a kitchen unit was removed I saw an earth cable (maybe 2.5) coming out of a socket and terminating at the hot and cold water pipes...

was bonding to extraneous pipes acceptable from a cpc,
or could earths be utilized from extraneous parts,
and the sockets are all on 30a but its a radial, or at least most of seems spurred.

 

[micknew]

Sounds like the installation was never installed to any regulations.
DIY job.

 

[Rockingit]

It was a fashion years ago to use the incoming water pipe as the earth rod, so at a stretch you could extend that principle up and into a flat (not saying it's right, btw) but if there was a TN-S connection present then it's anyone's guess.

Phone call to the DNO to find out what it SHOULD be, and go from there. If you're really lucky they'll still have it on record as TN-S and you can reinstate it. If not.....have fun!

 

[guest119]

Sounds like bog standard supplementary bonding.
Hot to cold to sink, then to ring?

Boydy