Earthing Supply Type help -High Earth Loop Impedance reading

[securespark]

Yeah, OK. I replied before reading every post....

 

[ban-all-sheds]

Shameful.

I would never do such a thing.

 

[securespark]

We've all done it at one time or another. Some more than others.

 

[grhughes74]

Definitely looks like TN-S on split con to me.

OP, do you know what the Ze reading for the supply was?

I don't know what the reading was before the extension was built but the reading now is 3.31 ohms.

Thank you all for the info. All I need to do now is find someone to correct the problem for me. Both UKPowerNetworks and my builder are adamant that the other is responsible for fixing it.

 

[JohnW2]

Definitely looks like TN-S on split con to me. OP, do you know what the Ze reading for the supply was?

I don't know what the reading was before the extension was built but the reading now is 3.31 ohms. Thank you all for the info. All I need to do now is find someone to correct the problem for me. Both UKPowerNetworks and my builder are adamant that the other is responsible for fixing it.

The irony is that 3.31Ω is far lower than anything you would achieve with an earth rod alone. Indeed, if you added an earth rod to the current setup, you would hardly notice the reduction from that 3.31Ω.

You really do need to try to press to get the present earth 'mended', since switching to an 'earth rod only' (TT) system or adding an earth rod to the existing TN-S setup could well have knock-on repercussions on other things about your installation that had to be changed - and 'mending it' is really down to UKPN, I would have thought.

Kind Regards, John.

 

[securespark]

I think I would get back to UKPN and ask them to confirm the supply type here. If they are suggesting you get a rod, then I suspect that despite appearances, you may have a TT supply, in which case they have no responsibility to provide an earth for you. The 3.31 may be via pipework etc...

Have UKPN done a proper Ze test on the supply (ie disconnected the main earthing conductor)?

If they confirm their supply as a TN supply, and there is an existing earth terminal that was historically provided by the electricity supply company,
then they have a duty to maintain it.

Ring the emergency number and report it as an emergency, quoting "high Ze" and the value. Make a note of the reference number you are given and ask what time you will be attended by.