In article ,
"G&M" writes:
You should report this as a fault to your distributor.
There's not enough info to tell what's wrong here -- it would be
interesting to know the three voltages L-N, L-real ground, N-real
ground, but don't try measuring these unless you are compitent at
working with mains voltages.

L-N is 251 volts. Drops slightly when the end farm is on load but not much.
L-N at the first farm is over the 253 volt limit but they don't want to
complain. L-N at the end farm can go as low as about 210 volts on load I
gather but they have been told tough.

N-real ground is typically 45 volts. It varies from 40 volts upwards but I
have never seen more than 50 volts. Do you think this still indicates a
problem at the PEN which as I say is about 3/4 mile away ?

You only reported 2 of the 3 measurements.

--
Andrew Gabriel