On 1/19/2015 8:55 PM, Jim Brown wrote:
On Mon,1/19/2015 5:29 PM, Brian Carling wrote:
The advice varies about this considerably. This week is the first
time I've even heard of UF ER or conductive concrete!
The professional experts that I know recommend putting a 20 to 30
foot ground rod into the ground at each corner of your house and
connecting heavy gauge copper conductors up to lightning rodsup on
the roof.
You and your "experts" are only 70 years behind. :)
Well, not quite 70 years but for a very long time.. It was developed 70
years ago, but it became generally known with the paper published in
1963 (52 years ago) and with the NEC adoption in 1968, but that's still
a long, long time and before many hams were born. OTOH I'm surprised
that any "old timers, or experts" would be unaware of it.
Jim has enclosed a link to this entry. It is well worth reading for any
ham. I included a clip from the history with credits which should be
permissible.
Although I was well aware of the UFER ground, named after its creator, I
was not aware of its exceptional effectiveness. Although the ground
system I have is very effective, with the price of copper, ground rods,
and CadWeld oneShots, it would be prohibitively expensive today.
Concrete is expensive, but in 2000 I could have saved considerably using
a UFER ground compared to 32, or 33 8' ground rods CadWelded to over 600
feet of bare #2 as Copper is not recommended in the UFER ground due to
the very high PH of concrete. That high PH is also why Aluminum towers
should never be imbedded in concrete as a high PH corrodes Aluminum
readily eating away at the material. That large network also renders a
large portion of my back yard unsuitable for anything other than growing
grass and shrubs. so a garden is out. OTOH at our age it is unlikely
the yard will be use for anything else.
Instead of copper, steel (plain old rerod) is recommended to be the
imbedded material because the high PH concrete may cause the Copper to
flake, reducing its conductivity to the concrete
Incidentally, my wife has informed me that she is NOT going to tend to a
garden again! <:-)) Her last garden was finished when we move here in
1984. (Approaching 31 years ago)
Ufer ground
From Wikipedia, the free encyclopedia
(Redirected from Ufer Ground
<https://en.wikipedia.org/w/index.php?title=Ufer_Ground&redirect=no>)
The *Ufer Ground* is an electrical earth grounding
<https://en.wikipedia.org/wiki/Ground_%28electricity%29>
The UFER ground was developed during WWII. his results were published in
a paper presented at the IEEE Western Appliance Technical Conference in
1963.^[1] <https://en.wikipedia.org/wiki/Ufer_ground#cite_note-1> The
use of concrete enclosed grounding conductors was added to the U.S.
National Electrical Code
<https://en.wikipedia.org/wiki/National_Electrical_Code> (NEC) in 1968.
It was not required to be used if a water pipe or other grounding
electrode was present. In 1978, the NEC required rebar to be used as a
grounding electrode if present. The NEC refers to this type of ground as
a "Concrete Encased Electrode" (CEE) instead of using the name Ufer ground.
https://en.wikipedia.org/wiki/Ufer_ground Wikipedia
http://en.wikipedia.org/wiki/Ufer_ground
The Ufer ground is VERY well known among the Electrical Engineers who
design power systems for all sorts of buildings.
73, Jim K9YC
-- 73 Roger (K8RI)
---
This email has been checked for viruses by Avast antivirus software.
http://www.avast.com
_______________________________________________
_______________________________________________
TowerTalk mailing list
TowerTalk@contesting.com
http://lists.contesting.com/mailman/listinfo/towertalk
|