JC:
I (and most others here on TowerTalk) would advise against placing copper
tubing in intimate contact with galvanized steel. So that would eliminate your
first suggested alternative.
I use Harger 222T connectors to fasten my #2 solid tinned copper ground
wires to the legs of my Trylon tower (at factory-drilled holes.) I also use
Harger #213T connectors to connect these same #2 wires to other places on the
tower steel, like at the coax ground points at the top and bottom of the tower.
These conenctors meet all the lightning specs you site in UL96. They provide
1.5 sqin of surface area in contact with the tower steel; they have two
channels that can firmly grasp two ground wires for the spec'd 1.5 inch length;
and they include a sharp point in each channel that pierces each ground wire to
hold it in place. The connectors also include sets of grooves on the contact
portion of the connector to permit drainage of rainwater away from the surface
underneath the clamp.
I suggest you look into using either of these connector assemblies,
including the <T> version - electroplated tin - to connect your TINNED copper
tubing to the tower legs. Or you can squeeze the flattened copper tubing
against a piece of stainless steel, which is held against the tower galvanized
surface with a SS hose clamp. But this is a bit more complicated thatn the
staightforward Harger clamps that are made for this purpose. Just make sure
your tubing is at least #2 gauge in size - the minimum for Harger clamps.
73 de
Gene Smar AD3F
-------------- Original message ----------------------
From: "JC Smith" <jc-smith@comcast.net>
> I'm using copper tubing, run inside garden hose while above ground, for my
> tower grounding "straps." I usually do the same thing (flatten the ends and
> make large terminal lugs out of them), but where corrosion might be a
> problem, like on battery busses, I've been tinning the copper "terminals"
> with tin/lead solder. I'm wondering if this will be good for connection to
> the tower? I know there are terminals (bonding lugs) designed to make this
> connection. Looking at some of the catalogs it appears they are made of all
> sorts of metals. I see bronze, electro tin plated bronze, and aluminum
> (which is probably intended for aluminum wire). There are also
> electroplated tinned copper lugs and unplated copper flat strap clamps,
> which are designated as tower grounding components (Harger catalog). Banjo
> clamps of tinned bronze are also shown specifically for attachment to
> lattice towers. Surface area in contact with the tower and in contact with
> the conductor appears to be a primary consideration. UL 96 Standard for
> Lightning Protection Components says a minimum of 1.5 in. of conductor must
> be secured within the connector, and also that 1.5 in. of surface contact
> between conductor and ground rod is required. Obviously, bonding surface
> area between the lug and the tower is important but I didn't see a minimum
> specified.
>
> It wouldn't be too difficult to fold and crimp the ends of the copper tube
> so that it would fit inside these commercial terminals just like a heavy
> gauge wire would, but it seems to be a better connection to the tower if the
> intermediate piece (the lug) was eliminated and the ground strap (the copper
> tube) secured directly to the tower (better continuous conductor surface
> area and fewer mechanical connections). What does the collective wisdom
> here think? Attach the bare copper strap directly to the galvanized tower,
> attach the tinned strap directly to the tower, or use some sort of
> intermediate lug?
>
> Thanks & 73 - JC, K0HPS
>
>
> -----Original Message-----
> From: towertalk-bounces@contesting.com
> [mailto:towertalk-bounces@contesting.com]On Behalf Of Cqtestk4xs@aol.com
> Sent: Thursday, July 20, 2006 4:08 AM
> To: TOWERTALK@contesting.com
> Subject: Re: [TowerTalk] Grounding the tower..alternatives
>
> You need not go to the bother of flattening the hardline. You have the same
> surface area with it round or flattened...........................K4FMX
> ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>
> The flattening of the hardline was only on the ends. This made it easier
> to
> put flat against the tower (with a thin layer of stainless to prevent
> corrosion) and against the ground rod.
>
> Bill K4XS
> _______________________________________________
>
>
>
> _______________________________________________
> TowerTalk mailing list
> TowerTalk@contesting.com
> http://lists.contesting.com/mailman/listinfo/towertalk
>
> _______________________________________________
>
>
>
> _______________________________________________
> TowerTalk mailing list
> TowerTalk@contesting.com
> http://lists.contesting.com/mailman/listinfo/towertalk
_______________________________________________
_______________________________________________
TowerTalk mailing list
TowerTalk@contesting.com
http://lists.contesting.com/mailman/listinfo/towertalk
|