120V from water tap to true earth

[Midwest]

The other night, neighbour knocked my door. She said she'd gone to use their outdoor tap, and she thought she'd got a shock. Went and had a look, and they have one of those Rolec tap pods, with combined water tap and electrical socket. I've not been trading for a few years now, but I got out my MFT to do a Zs test on the socket. However, it wouldn't carry out the test, and came up with 'CONN', which in the past I knew that was either a connection problem or voltage on cpc. Got the same result on socket in house, my MFT then went out on flat battery.

I then got my voltage tester, and from tap to extension lead (neutral), I got 120V, same in house. No SFCU for Rolec pod. I'd taken boots off to go in house, but thought I'd just unscrew pod lid to see what was going on inside. You guessed it, got belt from tap

At this point, I suggested we isolate that particular RF & call out DNO (PME supply I'm thinking lost neutral). Didn't want to turn off RF, large chest freezer in garage. But she did call out DNO. Following morning before I went to work I knocked the door. DNO checked their supply & main earth, all good. They made her turn off RF; she ran extension lead from 1st floor RFC (didn't think of that). Suggested calling an electrician I knew, but she was going to wait for hubby to come home from Town that evening.

Anyhow, when I got home from work, hubby had been on the case for a few hours, and he reckoned he found the fault. Dodgy Wago connector on earth somewhere. He's had an outdoor extension, with electrics done, either by him or Bob the Builder.

My question, could a poor earth connection, cause a potential between earth and true earth?

 

[LastManOnline]

In the U.K. a broken N will rise to 230v if there is any load on the circuit after the break.

Correct.But in the case of the OP where it appears some unconventional electrics has been carried out I,m wondering how could reconnecting an earth possibly lead to the voltage on earthed metalwork been removed?The only examples I can come up with are..

1) intentional earth leakage belonging to the affected circuit.

2) The earth wire has been used as a return wire and is now in effect " a broken neutral" .However as it's an earth wire it may be connected with other metalwork that offer some alternative but high resistance paths to ground.This would cause a volt drop.Entirely speculation on my part

 

[Midwest]

Firstly I must add, I cannot be certain the electrical additions have been carried out by my neighbours or anyone not competent. Also the main supply has been verified as in order by the DNO.

Therefore the fault was somewherein the property, could of been in the addition or possibly in the existing, although you’d of thought that would of been found by the original EIC, but you never know.

Neighbours appear to have gone away for the weekend, so been unable to offer Zs test at pod. Her indoors is saying not to get involved. I’ll see, and perhaps pick my moment. But he is a bit of a very confident type, if you get my drift.

 

[LastManOnline]

I

Neighbours appear to have gone away for the weekend, so been unable to offer Zs test at pod.

I, m progressive leaning towards the possibility there is actually nothing wrong and you could end up trying to fix something that is, nt broken.
The DNO found nothing wrong with the supply or the earthing.
They isolated the problem to the ring.
The issue was solved when the loose earth was reconnected.

Where does that leave us?
Neither the homeowner nor yourself mentioned that any appliances had stopped working,which confirms the integrity of Land N and rules out one of my previous suggestions about the earth been used as a, return wire.
That brings us back to intentional earth leakage from one (or more) of the appliances.The circuit for this current has now been opened, creating a "broken neutral" type scenario. This voltage will appear on all class 1 appliances and metalwork connected to them on the affected part of the circuit.

The above is easily established by plugging out all appliances and isolating all fixing appliances on the ring. Disconnect the earth that caused the initial problem. Test at the tap and it should be volt free. Plug the appliances back in progressively, testing as you go and you should find the 120 volts reappearing on the tap.

I have experienced the above problem on several occasions