OT for a sec: US wiring sources of info

[Steve Thatcher]

3 or so meter grounding rod driven into the earth and then attached with a single run of wire to the meter box and the service panel. Current standards usually require 12 gauge copper wire with three wires in it for 110v runs. White, black, and a ground wire (usually 14 gauge). For the 110v runs, each has the ground wire and white wire connected to the panel's ground. Black goes to the breaker and becomes the hot lead to circuits. The ground wire should be connected to any metal boxes and should be attached to the ground terminals on switches and outlets.

hope that covers what you were asking.

What is the earthing arrangement?

Simon

--
------------------------------------------------------------------------
"Well, an engineer is not concerned with the truth; that is left to
philosophers and theologians: the prime concern of an engineer is
the utility of the final product."
Lectures on the Electrical Properties of Materials, L.Solymar, D.Walsh