[TowerTalk] right sizing strap for tower connections

[Jeff Blaine]

In the discussion of the ground connection, a mix of guys commented or sent 
pics of round conductors where others are using strap.  The general comment 
was that strap is better which I think means lower R & L for the run.

At the outset I was planning to use 3-gauge stranded insulated wire which I 
have a lot of on hand.  Wire would run from the tower leg clamp, over to the 
edge of the concrete and then down to a copper ring bus where the individual 
runners to the rest in-ground stuff was.

But for the conductor run from tower leg to ground system I am wondering 
what width of strap would be better than the 3 gauge stranded wire.  While I 
realize that wider is better on the strap width, I wonder what width of 
strap would approximate the 3-gauge wire?

73/jeff/ac0c
www.ac0c.com
alpha-charlie-zero-charlie

-----Original Message----- 
From: Clay Autery
Sent: Tuesday, October 17, 2017 7:32 AM
To: towertalk at contesting.com
Subject: Re: [TowerTalk] Fwd: Grounding connection to tower legs

On 10/16/2017 6:18 PM, jimlux wrote:
> On 10/16/17 3:44 PM, Clay Autery wrote:
>
> Just off the cuff, I think this would be overkill for *lightning 
> protection*, which is why you don't see this approach in the usual 
> commercial radio installation handbooks (e.g. R56)
>
> you don't worry so much about low resistance or contact area - if it's 
> reasonably close, the lightning current will arc from one to the other and 
> a high current spark is VERY low impedance.
>
> And with a long strap, if it does arc underneath, you've got somewhere for 
> pressure to build up.
>
> What *is* important is mechanical strength - as Jim K9YC pointed out,
Well...  For me?  When I have many thousands of dollars in equipment at
risk, there is no such thing as "overkill".  :)

Anything I can do to pump as much of the strike into the ground prior to
entry into the shack, and thence to reduce the step potential, I will
do.  :)
It doesn't take that much "extra" to do a job right.

Who said anything about a "long strap"?  I was responding to the man's
question about the clamp...
But since you bring it up.... yes...  a strap as wide as I can make
work, AND as short as possible and of sufficient mechanical strength to
stand up to the forces imparted. Apologize...  I assumed that those were
givens.  <big smile>

73,

______________________
Clay Autery, KY5G
MONTAC Enterprises
(318) 518-1389


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