View Single Post
  #9   Report Post  
Old September 24th 09, 07:42 PM posted to rec.radio.amateur.antenna
Dave Platt Dave Platt is offline
external usenet poster
 
First recorded activity by RadioBanter: Jul 2006
Posts: 464
Default Aluminum as a ground system

In article ,
Michael Coslo wrote:

Only concern I would have is that the electrical connections are
properly made. AL's talent for oxidizing has been a problem in the past
with house wiring.


A good point.

The National Electric Code has some fairly specific requirements for
how grounding system connections must be made. Soldering is not
permitted, as the high temperatures which can occur at such
connections during a lighting strike can blow the soldered connection
apart. Strong mechanical connections, or welding (e.g. "CadWeld"
thermite-type welding) is required.

I just ran across the following:

http://www.homeinspector.org/resourc...-Grounding.pdf

It indicates that the NEC forbids the use of aluminum conductors for
grounding "where in direct contact with masonry or earth. Aluminum
conductors require 18 inches of clearance from earth." (NEC
paragraphs 250-91a and 250-92a are cited).

There's also a note on the citation: "ATJ note: we have field
reports of complete failure of uninsulated bare aluminum grounding
conductor wire when it was not properly protected from corrosion - for
example where left touching a masonry foundation wall."

It sounds to me as using aluminum wire as a lightning ground system
is a poor idea.

--
Dave Platt AE6EO
Friends of Jade Warrior home page: http://www.radagast.org/jade-warrior
I do _not_ wish to receive unsolicited commercial email, and I will
boycott any company which has the gall to send me such ads!