This is true Revision F
The moving force behind this revision is Anchor Guard who manufacture cathodic
protection. I
don't know for sure, but I think they sell the grounding products they're
calling for in 222-F.
Could it be they aren't altruistic?
The problem is that you can severe corrosion on the anchor rod between the part
that's in
concrete and the part that's in soil. Likewise the part in soil if soil layers
vary in their pH.
Anchor Guard has an interesting monograph (7 pg) on the subject. Send me fax #
or
snail mail address and I'll pass it along. Send this to my work e-mail, please
<bobwanderer@polyphaser.com>
Aluminum, Galvanize, Tin are attacked by alkaline soil. This soil predominates
in the western
part of the US. Copper is attacked by acidic soil, common in the eastern states.
If the two dissimilar metals are far enough apart, there ought not be any
problem. Distance
would probably depend on the conductivity of the soil. I personally think there
are other
causes, although this particular scenario does probably occur often enough to
be of concern.
73,
Bob Wanderer AA0CY
Sr Appl Engr
PolyPhaser Corp.
----------
From: Frank Donovan[SMTP:donovanf@sgate.com]
Sent: Wednesday, April 23, 1997 1:20 PM
To: Bill Tippett; towertalk@contesting.com
Subject: Re: [TowerTalk] Verticals of Rohn 25
As a matter of interest to Towertalkians, the new version of EIA/TIA-222
specifies that copper wire SHALL NOT be used for ground wires, ground rods
or ground clamps. All new towers installed under EIA/TIA-222
specifications must use galvanized ground rods, galvanized steel wire (ie
guy wire!) for grounding conductors, and galvanized connectors or
exothermically welded connections. Tinned copper wire may be substituted
for galvanized steel wire when the conductor must be buried. Bare copper
is no longer allowed in any grounding application, either at the tower
base or at the guy anchors.
This change came about as a result of research that demonstrated that
copper ground rods in proximity to tower foundations and steel guy anchors
tended to accelerate the corrosion of the steel members, leading to sudden
catastrophic failure!
73
Frank
W3LPL
donovanf@sgate.com
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