"Michael Coslo" wrote in message
...
Ed wrote:
I am only interested in the long term reliability of an aluminum ground
system in comparison to the more common copper system. This is for
lightning suppression only, I am not addressing RF issues. I am
wondering if aluminum can handle the potential surge currents that copper
can... and how well does its ground conductivity work when buried, when
compared to copper.


For surge currents only, Al would need to be thicker than Cu of equal
handling capacity. If you are stressing things to the max, Al has a lower
melting point.

It would work for RF ground also. The oxide layer would not affect the
performance. Lots of us use insulated copper wire for ground radials.



The OP referred to a 'vault ground ring', not radials.

Furze is a major supplier of lightning protection products in the UK and
they don't favour aluminium for earth connections:
http://www.furse.com/elp/earprod.htm. I understand copper and
copper-plated-steel is still used for neutral earth connections by UK
electric power supply companies as well - the oxide layer on aluminium and
its alloys, if present, must have some value of breakdown voltage and
anything that elevates neutral above earth that can be avoided has to be a
bad thing.

Chris