Topband: Radial Plate Designs - dual hole compression lugs

[Bill Wichers]

Panduit makes these type of lugs too. Some wholesale electric supply houses have them but you want the copper ones, not the aluminum kind. They are both plated and look the same, but the copper ones are noticeably heavier. You need a hydraulic compression tool to install them and the correct die for each lug (dieless crimpers aren't as good). The hydraulic tools show up on eBay for $200+, dies are about $60-100 each. 

We use these in the telecom industry for grounding and dc power cable. The silicon bronze hardware used to be required. It was used for corrosion resistance and because it doesn't react with battery fumes in power rooms. Stainless hardware is now also acceptable. You should not use galvanized hardware with these lugs except indoors and then it should be grade 5 by code. You use a flat washer on either side and a split lock washer with the nut. Best practice is to use the brown "no-ox" as a film between the lug and whatever you attach it too. Done this way the connection will last forever. Note that you need one crimp between each set of colored bands on the lug for a proper installation. 

Check out c-taps and h-taps too. These and cadweld shots are the only "right" way to do a proper ground system for high currents. 

All that said, I just solder my own radials :-) I do use the compression lugs and c-taps for my lightning ground ring. At work I always spec these for anything critical (dc plant, ups, generator, etc.). They cost more than mechanical (Allen screw) lugs but they're maintenance free and last forever when installed correctly. 

If anyone does want to use these be aware that some of the lugs have minor differences in their  hole spacings but major price differences. I know from my own experience that the two-hole 750kcmil lug with 1" hole spacing is around $40 each but the same thing with 1.75" spacing is about $17 each. I think the price differences are due to market volume differences but for ham purposes it is worth finding which is the cheapest hole arrangement and then designing around that. NEMA standard spacing is 1.75" for most of the larger lug sizes. 

-Bill

Sent from my iPad

> On Feb 4, 2015, at 8:48 PM, m.r. <mrc02 at kinderteacher.com> wrote:
> 
> http://ecat.burndy.com/Comergent/burndy/search/YA*FX*
> 
> this is just the top line manufacturer of compression lugs, the link should take you to the page for dual hole lugs
> 
> Similar products are available from a number of suppliers. All the major communications hardware suppliers have a variety - Talley, Tessco, SitePro1, to name just a few
> 
> Be prepared for sticker shock,  These are NOT your surplus or swap meet lugs
> 
> Sitepro probably has them at the lowest price in small (or large ) quantity
> 
> http://www.sitepro1.com/store/cart.php?m=product_list&c=15     this list shows both single and double hole, long and short shank
> 
> They also have galvanized bolts and nuts - and stainless - to bolt it all together with. Fanatics use silicon bronze bolts, nuts, washers when making a ground system  - usually for surge/lightening reduction grounding systems, but they will work just fine for a radial system.
> 
> Robin
> WA6CDR
> 
> ----- Original Message ----- From: "Gary Smith" <Gary at ka1j.com>
> To: <Topband at contesting.com>
> Sent: Wednesday, February 04, 2015 10:57
> Subject: Re: Topband: Radial Plate Designs
> 
> 
>> I've never seen the dual hole lugs but they certainly would stop the
>> attachments from moving. I like the idea.
>> 
>> I made my own radial plate from a 18" x 18" x 3/16" SS plate with a
>> square hole cut in the center for a butternut to be placed. I have 20
>> 1/4" holes cut in per side. I used SS bolts, split ring "keepers" on
>> each side of the plate, washers & nuts. I used Penatrox on both sides
>> of the plate & inbetwixt all connections. For solder to the radials I
>> used non-lead plumbing solder and assembled this 4 or 5 years ago. It
>> rests on a bog on a salt water marsh, one that was under salt water
>> thanks to Hurricane Sandy (My Ameritron RCS-8V used to select which
>> antenna wire to use was just barely above the water and spared
>> damage).
>> 
>> This fall I went down to check the connections and remove the debris
>> that accumulates on the plate, it was totally covered by dirt and
>> organic material. In these rather harsh conditions I can say there
>> was no visible oxidation whatsoever on the solder, had I used lead,
>> it would have been significant. The 60 or so 130' radials were firmly
>> attached albeit several nuts did turn a bit as I tightened them down.
>> The Penetrox was still obviously present and the only sign of damage
>> was oxidation to the exposed copper braids at the end of all coax
>> leading to the 5 different antenna. I replaced the coax and all is
>> good for another year. How I get my wires over the trees you can see
>> at the bottom of my QRZ page.
>> 
>> In summary;
>> 
>> - In Salt Marsh/Salt water conditions SS plate is ideal as long as
>> the hardware also is SS.
>> 
>> - Leadless plumbing solder is an excellent choice for durability and
>> secure attachment to the radials.
>> 
>> - Not sure if the use of split ring "keepers" are necessary but due
>> to the slipperiness of the Penatrox I decided to use them to gain a
>> better purchase while tightening the bolts. Essentially, the
>> connections have remained secure for the last 4-5 years.
>> 
>> 73,
>> 
>> Gary KA1J
>> 
>> ---
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