Live earth

[Adam_151]

No, your earth is obtained by the rod in the floor (the neutral side of their transformer is connected to a rod at their end), but the impediance of such a connection is higher than the types of earth provided directly (TNS - Supplier gives you earth wire, TNCS - Supplier gives you an earth from the neutral)

This means that you need an RCD on all circuits to disconnect in the event of an earth fault, now it looks like the main board is thus equipped, but there seem to be other boards connected via service blocks which don't seem to be.

The problem you are having is most likely down to the earthing rod having a much higher impedance than normally allowed even for a rod, this may be down to it being located under the floor instead of outside

If you talk to your supplier, they might be able to provide you with a TNCS earth

 

[JohnD]

Excuse my ignorance but should there be an earth connection between the incoming supply (SWEB) and consumer earthing as there doesn't seem to any?

It used to be common for overhead supplies in country areas not to include earth provision (though I'm told this is now less common)

 

[Adam_151]

You either have a supplier earth (TN) or your own earth (TT). Never both.

I beleive the IEE advise the fitting of an earth rod on TNCS systems to re-inforce the M on PME and it seems to make sense, the better a TNCS earth is tied down to physical earth, the better

 

[JohnD]

You either have a supplier earth (TN) or your own earth (TT). Never both.

I beleive the IEE advise the fitting of an earth rod on TNCS systems to re-inforce the M on PME and it seems to make sense, the better a TNCS earth is tied down to physical earth, the better

fair point, and as the water and has pipes are bonded to the MET we're halfway there (they're just unreliable as you may not know how far they're metal or plastic)

 

[Steve]

You either have a supplier earth (TN) or your own earth (TT). Never both.

I beleive the IEE advise the fitting of an earth rod on TNCS systems to re-inforce the M on PME and it seems to make sense, the better a TNCS earth is tied down to physical earth, the better

Is that a new thing? I have only ever heard people saying an extra house earth rod on TNCS is a bad thing? or am i thinking of something else and confusing myself again?

 

[peter_226]

Thanks for your responses,

I have contacted the previous owner and SWEB and have been told that I have TNCS which I understand as being supplier earth from neutral. I presume my earth rod is not necessarily required but I shall leave it connected unless tod otherwise.

Can someone please tell me what can cause:-
Live/neutral = 240 Live/earth = 130 Neutral/earth = 80

Could it be because I have an earth rod with TNCS?

What can I try to detect or isolate the fault?


Thank you

 

[JohnD]

TNC-S is the most usual method in UK; however, in this case, there ought to be a plate or label near your meter saying "Protective Multiple Earthing" which I didn't see in the pic, and there ought to be a earth wire going to the side of the cable head, which I didn't see.

Have a look and see if either of these are present; as you may not have it.

If you do have it, then you would not get these floating voltages if it was correctly installed and working. Neutral and Earth would be connected together so at (almost) the same potential (depending where you measure it).

If your Electricity Supplier thinks you have, and you haven't, you could tell them and ask them to install it. They probably will, but may want to make a charge and/or have a safety inspection arranged by you first.

 

[Adam_151]

Can someone please tell me what can cause:-
Live/neutral = 240 Live/earth = 130 Neutral/earth = 80

A floating earth

I have contacted the previous owner and SWEB and have been told that I have TNCS which I understand as being supplier earth from neutral.

That is indeed correct, but as you say here:

Excuse my ignorance but should there be an earth connection between the incoming supply (SWEB) and consumer earthing as there doesn't seem to any?

I looks like you have got SFA connected to your TNCS earth terminal (the link is made at the service head, NOT in the CU, so you should have an earth wire comeing out of the SWEB supply if you have TNCS)

Could it be because I have an earth rod with TNCS?

No, because your TNCS isn't actually connected, and your earth rod is very high impedance (even for an earth rod)

 

[peter_226]

I cannot see any earth wire coming out of SWEB equipment.

I shall install another earthing rod in a suitably damp place outside the house and connect it to the earthing block. If this doesn't work I shall call in a qualified electrician.

Thank you very much everyone for your patience, help and time. It is much appreciated.