Live pipework problem

Chocolate · Apr 9, 2018

Evening all
Anyone any ideas on a voltage being present on pipework in a flat?
All bonding done and satisfactory Ze at board.
It’s a block of 3 which I’ve isolated all Power to two of the flats the third is a holiday home which I can’t access. I was thinking there is an issue either in the inaccessible flat or an external problem. Any ideas would be appreciated. The incomer to the two I can access is a tn-s 3 phase.
Cheers

Chocolate · Apr 10, 2018

It is looking like a neighbouring property that is a holiday home so this could drag on. The dno isolated as many properties as possible and the fault was still there. Dno engineer said he would phone me back which will probably be tomorrow.

Fish6328 · Apr 14, 2018

Evening,
I have just found a problem that I had with taps giving us a little buzz every now and then, but not enough to trip the RCD's in the CU. I found we had an intermittent 22v coming through the main earth on a TN-S system. I found the 22v by checking the bonding and then measuring between the MET and the main earth. To cut a long story short, it was a fault in the street lights outside that was sending voltage to the earth at the transformer down the road.

Deleted member 26818 · Apr 14, 2018

Fish6328 said:
Evening,
I have just found a problem that I had with taps giving us a little buzz every now and then, but not enough to trip the RCD's in the CU. I found we had an intermittent 22v coming through the main earth on a TN-S system. I found the 22v by checking the bonding and then measuring between the MET and the main earth. To cut a long story short, it was a fault in the street lights outside that was sending voltage to the earth at the transformer down the road.

Earth fault voltage from outside the installation will not trip RCDs inside the installation.

stevels4 · Apr 16, 2018

Chocolate said:
Was measuring 48 volts using mft. I have measured ze at cut out in flat. The cut out in flat is tapped off the 3 phase tns at entrance stairwell to two of the flats. Im heading back tomorrow to make sure I’ve not missed anything stupid, cheers for replies so far.

And the Ze at the cut out was?

Squid · Apr 16, 2018

Did hear a story a few years ago about the gas engineers that go a shock when cutting a gas pipe as the home owner bypassed the meter and stuck the neural able to the gas pipe, may be an "Urban Myth"