Earthing & electrical suppliers

dtec dave · Nov 30, 2017

Evening..

So, I'm working on a house that has been split into 2 flats and have been asked to do a board change in the downstairs flat. The earthing arrangement is TNS but I noticed that there is an earth connected between the neutral of the cut out and the earth terminal block to create a PME, on disconnecting this earth I am getting a Ze reading of 107 ohms with an earth cable connected to the incoming cable sheath. I rang Northern Powergrid and they informed me that they don't provide earths in this part of Leeds, fair enough earth electrode time.
But there is also a second Live and neutral going to the upstairs flat (no earth going up so I'm guessing that there is a home made PME up there also) which the landlord of the downstairs flat has just bought, I think I'm right in saying that the electrical supplier is responsible for this live and neutral. Would I have to install another earth electrode for the upstairs flat or could I share the one I'm installing downstairs?

Gavin John Hyde · Nov 30, 2017

There is a difference between supplying a new earth and maintaining an existing one, my understanding is that if one is provided then the dno must maintain it, if they subsequently remove the existing earth then they have to make it safe. a good example is a job i have seen in the past where western power changed a service head/cut out and left it without an earth, this was on a former barn/farm house and now owned by a solicitor. the new owner wasted no time in threatening western power with action and they subsequently admitted their mistake and fitted a rod. but they initially told the owner to get his own electrician to fit the rod! lesson. the dno often do not know there left hand from the right and make it up as they go.

Risteard · Nov 30, 2017

Don't mix up TN-C-S and PME. PME is one type of TN-C-S system, and if the network isn't PME then simply connecting onto the DNO's neutral won't make it one.

PEG · Nov 30, 2017

I'm having a problem envisioning someone telling me that they "don't provide earths in a part of town..." without a bit more detail regarding the earth that was provided, at one time,if it is an original TNS.

Unless that part of Leeds is mostly paxolin,sub-terre