[TowerTalk] Tower Grounding Electrode System

[Jim]

Bottom line…

 

A GOOD grounding system is an investment. If you want to invest in a good grounding system then:

 

Use multiple 8 foot copper plated ground rods spaced at about 10 to 16 feet. (farther than the length of the rod).

The top of the rod must be below the frost line.

 

The more the rods the better. Use a radial system from the entrance location if needed.

 

UFER grounding is also desired with new construction where concrete is to be poured, and bond with exothermic to the grounding system you just properly installed.

 

Exothermically  weld #2 AWG solid tined copper to the top of each rod.

All underground connections shall be exothermically welded together.

 

Use the approved connection methods (UL and NFPA70) to ground bars, towers, etc.

 

Bond the building electrical grounding system to the new ground system you have just properly installed.

 

 

I also bonded #2AWG tined solid to my 100’ steel 8” well casing that was 5 feet from my new tower base with a UL listed clamp. I did not have a Cadweld mold to use on my well casing. Since the connection is above ground, an approved mechanical lug is acceptable.

 

If you want to use SOLID strap above ground, use the proper terminations and appropriate conductive grease. NEVER use braided strap (braid) for a grounding system.

 

The mold for #2 AWG to ground rod is about $70.00. A #2 AWG run to #2 AWG tap cadweld mold is about $90.00. A used mold handle was about $25.00 on Ebay.

Avoid used molds. They are most likely worn out. New ones are not that more expensive.

 

I have successfully used caldweld one shots in the past. My last go round with them was a disaster, so I switched to the re-usable molds! They work perfect, and are what the professionals use.

 

https://www.gmesupply.com/ Has all the tools, cadweld (exothermic) molds and safety equipment you could ever use on a tower or grounding project. Their prices are the best I have found, and they take small orders from individuals.

 

BTW, the new version (revision C) of the Motorola R56 Standards for Communications Sites is free from Motorola Solutions. Just create an account and download the 800 page manual for free!

 

 

73

Jim W7RY

Motorola Solutions R56 SME.

 

 

 

 

 

From: Mickey Baker [mailto:fishflorida at gmail.com] 
Sent: Sunday, October 7, 2018 10:14 PM
To: jimw7ry at gmail.com
Subject: Re: [TowerTalk] Grounding wire choices

 

I have one, about 3 years old, strap from the grounding system into my SPG on the entry wall. Not buried, used the Harger copper bearing grease. It's tight. But I see your point.

 

I've seen them with an X cut in the strap, pushed down over the ground rod and silver soldered. It was pretty, but I didn't want to spend the time on my knees with a torch, and there's #2 cadwelded to the top of this rod running to the service entrance bond.

 

Good luck.

 

Mickey Baker, N4MB
Palm Beach Gardens
“Tell me, and I will listen. Show me, and I will understand. Involve me, and I will learn.” Teton Lakota, American Indian Saying.

 

 

On Sun, Oct 7, 2018 at 11:05 PM Jim <jimw7ry at gmail.com <mailto:jimw7ry at gmail.com> > wrote:

Did you see my response on the Tower Talk list?

 

I said…

 

 

Not the best way. But fine...

 

They corrode

They loosen up, I was never able to get mine to tighten up without spinning on the rod.

They are not NFPA 70 approved (National Electric Code) They are not UL approved.

 

If you have information to the contrary, please supply.

 

Thanks

73

Jim W7RY

Motorola Solutions R56 SME

 

 

 

 

From: Mickey Baker [mailto:fishflorida at gmail.com <mailto:fishflorida at gmail.com> ] 
Sent: Sunday, October 7, 2018 9:56 PM
To: jimw7ry at gmail.com <mailto:jimw7ry at gmail.com> 
Subject: Re: [TowerTalk] Grounding wire choices

 

 


Jim

	9:56 PM (57 minutes ago)



John... How do you attach that 2" copper strap to ground rods? 73 Jim W7RY 

 

http://www.kf7p.com/KF7P/Ground_Rod_Clamps.html

 

73,

 

Mickey N4MB