No main earth in domestic supply

[P&Q]

Hi everyone,

I got called in by a customer to install a new circuit for their cooker in the kitchen. So I went over and looked at the main supply and there was no earth. So I told them to get in touch with their supplier and ask about this missing main incoming earth cable and what is the Earthing system, and this afternoon he got back to me, and Scottish Power had simply said, some houses have earth and some really old ones don't - all they have is a Phase and a Neutral cable, and that's it and they're not gonna do anything about it.

I was just wondering, what the deal is with is, should I get back to them myself, or even set up a TT system myself?

Appreciate any advice in advanced guys

 

[chiplard]

How you gonna do that?

 

[saveloy]

turn supply into a tn-cs system!

How will you know if the supply is Tn-cs?

 

[Stress head]

If the dno connects it pme they will also seal the main fuse and meter tails for you.

 

[domestic spark]

i knew this statement would shock people, its an option if you dont want to wait around for there 3 houyr response time! sorry guys ill take it back, but somethimes you mite not have 3 hours!

 

[domestic spark]

obv i have never done this (just to clarify)

 

[P&Q]

Thanks for all your helpful advice guys, I'll get in touch with the DNO then.

 

[chiplard]

i knew this statement would shock people, its an option if you dont want to wait around for there 3 houyr response time! sorry guys ill take it back, but somethimes you mite not have 3 hours!

Really!

Please never do this, EVER!!!!!

 

[domestic spark]

How will you know if the supply is Tn-cs?

test main head and check pfc

 

[fire]

What do you mean PME it?

i think he means connect the 16mm earth with the neutral then measure ze if its less than 0.35 you are ok. not sure if thats good practice tho.

 

[domestic spark]

sorry p&q yes do that contact DNO. who will PME it for you!

 

[chiplard]

Try illegal!!!!!

Not bad practice.

With regards to fires' last post

 

[saveloy]

test main head and check pfc

Those tests will not confirm that the main supply cable is PME.

 

[Benny_Boy]

Try illegal!!!!!

Not bad practice.

With regards to fires' last post

Yep, if it's designed as a TT and you TNCS it, there are not generally enough DNO PME electrodes to raise the ground to the same potential as the MET.

net result = all extraneous conductive parts at 230v

So not only illegal but very dangerous (as eng54 correctly pointed out)

and thats as many abbreviations as I can squeeze into one sentence!

 

[terminator]

Yep, if it's designed as a TNS and you TNCS it, there are not generally enough DNO PME electrodes to raise the ground to the same potential as the MET.

net result = all extraneous conductive parts at 230v

So not only illegal but very dangerous (as eng54 correctly pointed out)

and thats as many abbreviations as I can squeeze into one sentence!

You could have sqeezed in CNE after PME!

But I do agree with you Benny, very dangerous (and stupid) thing to attempt.

 

[tony mc]

Totally aggree with Benny-boy re this leave any PME to the DNO who know that the neutral is correctly earthed, TT the property and make it safe.