6mm2 main earth? What service conductor size would that typically be used with?
Ragnar,
That would be used with a 16mm² phase conductor, note that this only applies to single phase 230V installations.
Anything poly-phase would have a minimum earthing lead size of 10mm².
Here, while larger conductors are often specified, the largest wire we're ever REQUIRED to run to a ground rod is #6, which is (seat-of-pants guess here) perhaps 12mm2.
A lot has been written on the topic, but it all boils down to this question: Just what doest the ground rod do? Whatever else it does, it certainly does not help to clear faults.
John,
#6 is equivalent to 10mm².
Believe me, I've seen some pretty weird things offered up as an Earth Electrode in my time, it seems to be the further you get out in the rural areas here, the more bizarre they become.
One old guy once tried to convince me that wrapping the Earthing Lead around an old axle off of a tractor (with the wheels and tyres still on it) and burying it, "should comply with the most stringent of electricity regulations".
