Sinking the ground rod several inches below the bottom of the foundation
hole and only running copper wire out the bottom of the concrete is no
problem. If house foundations use copper wire for Ufer grounds, then it
sounds safe to assume that copper embedded in concrete does not eventually
corrode away.
I figured that putting the copper rod below the foundation would increase
the sphere of influence (I think that is the correct term) compared to
putting a copper rod at the surface. A friend in the tower business
suggested that I should consider 1" diameter copper pipe sunk 20' into the
ground and I may consider doing that as well. I can pound in 8' ground rods
with a regular hammer here, so I suspect that with a little thought, I can
probably get 20' rods installed. I typically find water about 8-10 feet
below the surface here since I live on a lake, although I don't know if that
will improve the grounding at all. At the very least I'll also install
several 8' ground rods away from the tower base. Here in Western
Washington, we rarely get lightning and I've never heard of a local ham
being struck by lightning, but I might as well be safe.
73,
Clay W7CE
----- Original Message -----
From: "David Gilbert" <xdavid@cis-broadband.com>
To: <towertalk@contesting.com>
Sent: Thursday, September 13, 2007 1:07 PM
Subject: Re: [TowerTalk] Ufer ground using copper wire
>
> I assume you mean the top end of the copper clad steel ground rod
> shouldn't be embedded in the concrete, and that is true. But if he
> buries the Cadweld joint (wire to ground rod) in the dirt below the
> bottom of the hole, with only the copper wire entering the concrete, I
> can't see where there would be an issue (discounting the urban legends
> about exploding concrete, of course). Ufer grounds for house
> foundations have the copper wire exit the concrete below grade all of
> the time without worry about corrosion.
>
> 73,
> Dave AB7E
>
>
>
> Gary Schafer wrote:
>> You don't want anything sticking out of the concrete below grade. It will
>> corrode and work its way into the concrete.
>>
>> 73
>> Gary K4FMX
>>
>>
>>> -----Original Message-----
>>> From: towertalk-bounces@contesting.com [mailto:towertalk-
>>> bounces@contesting.com] On Behalf Of W7CE
>>> Sent: Thursday, September 13, 2007 10:43 AM
>>> To: towertalk@contesting.com
>>> Subject: [TowerTalk] Ufer ground using copper wire
>>>
>>> I'm planning on an Ufer ground in my new tower base. I've seen several
>>> sites recommending 20' or more of #2 or larger copper wire wrapped
>>> around
>>> the outside of the rebar cage. Are there any chemical reactions that
>>> make
>>> using copper a bad idea? I seem to recall reading something about that
>>> a
>>> while back, but now I can't find any mention of it.
>>>
>>> If copper is ok, I'm thinking about putting a pounding a copper ground
>>> rod
>>> into the bottom of the foundation hole. The copper wire will be
>>> attached
>>> to
>>> it and then wrap around the rebar cage and come out the top of the pad.
>>> Comments or suggestions anyone?
>>>
>>> 73,
>>> Clay W7CE
>>>
>>>
>>> _______________________________________________
>>>
>>>
>>>
>>> _______________________________________________
>>> TowerTalk mailing list
>>> TowerTalk@contesting.com
>>> http://lists.contesting.com/mailman/listinfo/towertalk
>>>
>>
>>
>> _______________________________________________
>>
>>
>>
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>>
>>
> _______________________________________________
>
>
>
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