The Natural Philosopher wrote:


Whilst you ar all talking, tell me what I have.

I have a substation in the garden. A coaxial cable comes from that with
the neutral pretty much attached to the Earth at the transformer, and my
earth busbar goes to a stake I drove into the ground about 5ft deep.

What do I have, and what the **** difference does it make to anything?

I am not sure, but I think that the earth and nuetral are also joined in
the meter cabinet

Having got the previous one probably wrong (the estimable Mr Stumbles
tells us the std concentric cable *does* make it easy to distinguish the
N cores from the E ones, so it really really is an ask-the-supplier
one), let's see if I can cock this one up too.

Given "e and n also joined in the meter cabinet", it's pretty definite
that your supplier is trying to give you TN-C-S, or PME. Your extra
earth stake either does naff-all, if it's supplementary to the
supplier's earth (other than creating an extra path for faults to earth
in your local area, which may not be what you want!) or have created a
TT supply, without an assurance that the earth resistance is low enough
or (I assume) the usual "well we'll put a 100mA RCD across the whole
lot" response.

The FAQ describes the earthing types and their effect. PME means you
need to be a tad more cautious in exporting the house earth to shed,
remote garij, and the like. TT means your supplier leaves you to sort
out a local earth, and these days you need to supplement with the
aforementioned whole-system RCD.