Andy Wade wrote:
MadJen wrote:

You had better check it is pme - ie the supply company provide you with an
earthing point and not a TT (with an earth rod).

It sounds as if the OP has a TN system, i.e. the DNO does provide an
earth connection. This might be either TN-S, where the earth comes via
a separate conductor (the sheath of a lead sheathed cable, or a separate
core in a concentric service cable), or TN-C-S (=PME) where the service
has a combined neutral and earth conductor.

It's PME - a single round cable connects to the main fuse unit & the
earth wire comes out of there. I would have put new wires in but it
means more opening up of the company's boxes.

The combined length of the wires to the CU from the meter is 2m. All
wiring is with meter tail type cable.

Currently the system is earthed using 16mm cable connected with an
earth block.


There has been no mention of the main bonding conductors in this
discussion. Where are those connected at the moment?

Bonding to pipework etc? I beleive that some 10mm earth wire comes out
of the CU and runs up into the ceiling/wall and that would be the
bonding.