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Feedback please: Homebrew grounding system


W3ESX
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Hello,

After having spoke with several seasoned hams about my setup, I've come to the conclusion that I need a grounding system for my rigs and antennas for safety purposes. For the past few days I've been doing some research and I've come up with a system that I think will work and will last, but I have some questions and I would like some feedback. Thanks in advance!

Summary

Basically, I want to:

  1. drive a new 8' long (5/8" diameter) ground rod on the side of my house,
  2. fasten a 1" width copper strap onto the rod (using a clamp) and run it up the siding of my house and into an enclosure (details to follow),
  3. fasten the copper strap to a grounding bar within the enclosure, which also has lightning arresters mounted to it
  4. mount the enclosure to the side of the house and run the coax into the enclosure, through the arresters, and then back out into my shack via a passthru panel

Enclosure

From my research, I think a simple AC disconnect box will serve as a great enclosure. I will of course rip out all of the guts that I don't need. I will use the existing punch-outs to create ingress/egress for the coax, with clamp-downs (my electrician terminology is weak, I know 😆) to hold the cables in place internally. I have some moldable non-adhesive sealant that will go around the ingress and egress points to waterproof them.

The grounding bar in the enclosure as-is is pretty small and the arresters are pretty bulky, so I think I will need to buy a new one. However, none that I've found on DX Engineering or HRO have been the right size (they are usually 10+" long and the box is 7" long). Any tips on a good one to purchase? I don't need a big one because at this QTH I will likely not be able to have more than the 2 antennas I already have (well, one operational, one planned).

Materials

This is pretty much everything I think I will need for the project:

Questions
I have the following questions:

  1. Which do you think would be a better setup: having the enclosure mounted high up near the antenna (shorter coax runs, longer ground strap runs) or low down near the grounding rod (longer coax runs, super short ground strap runs)? I'm leaning towards the latter because RG-8X is pretty cheap, and copper is expensive.
  2. What product(s) are recommended to serve as the "raceway" for the copper strap and/or coax from the enclosure to the grounding rod? Needs to be mountable to standard vinyl siding with minimal damage, and of course weather-resistant. Thinking D-channel, but haven't found any that is specifically listed as being outdoor-safe. Also has to be pretty wide diameter, as depending on the setup I may want to also run the coax through it along with the grounding strap.
    1. (Is it safe to run the grounding strap parallel to the coax? Is it safe to run the pre-arrester and post-arrester coax lines parallel to one another?)
  3. Any other red flags from reading my plan, either safety-wise or code-wise? I do not live in an HOA (thank goodness) but want to maintain code adherence wherever possible to avoid damaging value of home (and pissing off XYL).

😍👽😺 === Thanks!!! ===  😍👽😺 

I am open to any and all (constructive) feedback and am happy to engage in discussion or answer any clarifying questions.

73 DE W3ESX

 

 

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ELMER

Hi Jamison. Read the post, now I want to visualize and digest for a couple of hours. Minor first jump-off-the-page, I know you want to save, but you can do better than RG-8X and for this level of effort, I would. Another mini orange flag is your raceway. Careful not to build something that ultimately causes condensation. Weather-resistant yes, weather-proof, so to speak, no. My personal preference is to leave the copper exposed. As for the coax, if you get a good outdoor coax, as in the LMR-400 range, even the one that's meant for underground burial (Times Microwave LMR-400 Direct Burial Coaxial Cable - Black) or even the normal one, you won't need to protect it either. Maybe, just to give it a 'blending look' on the side of the house, you can get a long roll of 'house colored' heat shrink and camouflage it that way.

I hope I'm visualizing your setup correctly...

The real question, and it's a good one that deserves some thought, is the height of the box. I would mount it low, not to save on copper, but to have any current travel less distance to ground. I would not, however, allow for any parallel running. My setup has the ground wire moving away from the coax at 90-degrees in the hope that the current does not decide to travel along with the coax.

Last point about the box... I'm repeating what I said above... condensation!!! Make sure your box is very very very well vented.

Last little thought as per XYL and house value. One thing I had done for a friend is to build everything into runs of PVC pipe which were a couple of inches away from the wall of the house and simply fastened with three brackets (top/middle/bottom). We had then painted the PVC in the same color as the house. Basically invisible. Just a thought.

Hope this kinda/sorta helps.

Jim

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K3MRI, thank you for the detailed response!

Regarding the coax, I agree I could be doing better than 8X, but it's triple the price and I already have a ton of other stuff to buy...considering an incremental upgrade here, e.g. use the 8X I have now, and swap out for LMR-400 if I find a bunch on sale at a hamfest or some such. The advice of using higher-quality cable for the effort is heard and appreciated, though.

Sounds like you are recommending what I am calling Option B for the enclosure mounting, which is close to the ground. That's good, because that's the one I think I like better, too. Means longer coax runs and shorter ground strap runs. I'm OK with that, especially if it maximizes safety by shortening the path to ground.

I will have to do some thinking on the best way to route the cables down the siding and to the enclosure, especially because I also want to run a grounding wire from the passthru panel into the enclosure and, as you recommended, it should be orthogonal to the coax runs. PVC sounds like a great idea, I can get grey plastic conduit from Home Depot for nothing at all.

Thanks again for the idea vetting and advice. I will probably be doing up some diagrams shortly to aid in visualization, which I will post on this thread.

73 de W3ESX

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1176905403_GroundingSystemSketch-v1.jpeg.1f75d3517a27ed7d92569858d0c980bd.jpeg

Here is my initial diagram of the grounding system, mounted low to the ground as @K3MRI recommended. The diagram leaves a little to be desired, but it's a rough sketch so I'm OK with that.

The primary problem I'm struggling with at the moment is how to get a grounding strap from the passthru panel in the window down to the GND unit in the least-obvious way possible. I a) don't want it to drape over the window (the shutters are screwed to the house, so can't go behind them, sadly) and b) am worried about all the 90º turns that would have to be made to route it around all the windows and other items.

Any advice is welcome. I have started purchasing some of the parts for this that I know I will need, including a 40" mast that I am very excited to put up.

73 de W3ESX

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ELMER

Hi Jamison.

Oooops. Hold on.

First, great diagram. Would have been super helpful to better understand. My bad earlier.

Wrong approach... Don't shoot 😎

First a question which I should have asked earlier: HF or VHF/UHF? Also, in case I missed it, what type of coax? I ask these two because of signal loss. Based on this diagram, and the fact that you are upstairs, that ground unit has to go up up up and you have to run your grounding wire from upstairs to the ground. This will give you multiple benefits including much less coax.

I'll wait for your answer, but basically, I had not realized your shack was on the second floor.

😇

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No worries at all. Truthfully, I needed to write all that out in order to picture it in my head properly so as to create the diagram. So you are in the clear hi hi!

There will be two antennas run into this system: one dual-band UHF/VHF via a 10' Diamond vertical, the other a multi-band HF via a Chameleon EMCOMM III wire sloper. The coax lines for these two will run in parallel (the red and the blue in the diagram) first down to the grounding system, then back up to the passthru panel.

As for type of coax, I was originally going to try to use the RG-8X I had on hand, but I will likely need custom lengths anyways now that I have this diagram so I will most likely go ahead and make the jump to LMR-400 (as you recommended) for the better resiliency/signal quality.

The way I see it, I have two grounding solutions I need to figure out here:

  1. The coax lines from the antennas need to be run through lightning arresters contained in the box at ground level
  2. I need to run a grounding wire from the passthru panel down to the grounding box at ground level as well

I'm pretty confident on my solution for the former, but not as much so for the latter. Any advice welcome.

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ELMER

Here's my issue. A lightning arrester should be located as close as possible to the equipment that it is expected to protect. In large substations, for instance, arrestors are installed at take-off points of the lines and of the terminal apparatus. Also, it is good practice to have the arrester as close to the point of ingress of a coax into a building. Put those two together and being on the second floor, you have many good reasons to have the arrestors up high.

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Posted (edited)
10 minutes ago, K3MRI said:

Here's my issue. A lightning arrester should be located as close as possible to the equipment that it is expected to protect. In large substations, for instance, arrestors are installed at take-off points of the lines and of the terminal apparatus. Also, it is good practice to have the arrester as close to the point of ingress of a coax into a building. Put those two together and being on the second floor, you have many good reasons to have the arrestors up high.

Ah, I see! That could simplify the system a great deal, which would also save me some money.

So, based on this, I would put the lightning arresters directly on the passthru panel, i.e. with one side being fed by the coax from the antenna and the other side screwed directly into the coax ports on the passthru panel. I assume those ports are grounded to the GND terminal on the panel. (Is that a safe assumption?) All I would have to do then is bond the ground connections of the two lightning arresters to the ground strap coming out of the ground port, and then bond all of that down to the ground rod.

See below for reference of the passthru panel I am using:

image.png.3ae29c3c2f8ac4568266bd810beb81de.png

And here is the lightning arresters I intend to use:

image.png.c9eabf00126284c8d15ec386dc1fc9c3.png

Would all of this make for a better system? If I am understanding you correctly, this would save me a ton of coax, which can do nothing but good things for signal quality.

Edited by W3ESX
Add image of lightning arrester
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ELMER

My answer: ✌️😇

Yes to almost all. I'm going to say that it seems like a good idea to connect the arrester directly to the panel with a double barrel (male-male) but I've never done it. I've always added a very very short run of cable, as in inches. Why you ask? My lame excuse is because that's how my dad did it but frankly, why inject another few points of db loss in the connectors. Just make sure your barrel is of high quality and remember that there will be, ever so little of course, but there will be a little bit of 90-degree strain on that connection; which is why, I'm guessing, my dad added the little bit of cable. In his case, it was always today's equivalent of hardline. Again, not sure that it's necessary.

Looking forward to seeing photos of the finished project.

PS. Yes, safe assumption that the outer part of the SO is grounded to the chassis but, being stupidly overzealous, a nice little ohmmeter moment and beep would never hurt. But yes, they're connected (he says).

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15 minutes ago, K3MRI said:

My answer: ✌️😇

Yes to almost all. I'm going to say that it seems like a good idea to connect the arrester directly to the panel with a double barrel (male-male) but I've never done it. I've always added a very very short run of cable, as in inches. Why you ask? My lame excuse is because that's how my dad did it but frankly, why inject another few points of db loss in the connectors. Just make sure your barrel is of high quality and remember that there will be, ever so little of course, but there will be a little bit of 90-degree strain on that connection; which is why, I'm guessing, my dad added the little bit of cable. In his case, it was always today's equivalent of hardline. Again, not sure that it's necessary.

Looking forward to seeing photos of the finished project.

PS. Yes, safe assumption that the outer part of the SO is grounded to the chassis but, being stupidly overzealous, a nice little ohmmeter moment and beep would never hurt. But yes, they're connected (he says).

Excellent. I will get those orders placed for the passthru panel, the lightning arresters, some LMR-400, and some adapters and we will see where we stand.

Thanks for all the advice!

W3ESX OUT!

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ELMER
On 8/24/2021 at 2:18 PM, W3ESX said:

Excellent. I will get those orders placed for the pass-through panel, the lightning arresters, some LMR-400, and some adapters and we will see where we stand.

Thanks for all the advice!

W3ESX OUT!

Jameson W3ESX

First let me introduce myself and provide a little of my background. I'm retired out of over 45 years in the electrical craft. I spent a part of my career installing communications shelters from Tierra Del Fuego up to Alaska and from French Frigate Shoals to Tucson Arizona area. The number of shelters I managed the installation of is over 100. The most important part of the installations was usually the Grounding Electrode System. Many of the shelters which I oversaw were self contained and self powered. Since that doesn't bear on your project I'll leave it there.

A Ground Rod is a Grounding Electrode. Three Driven Rod Electrodes spaced 2X their length apart, bonded to each other, and then connected to a Ground Busbar or cable entry bulkhead is a Grounding Electrode System. This leads to several questions.

Were is your Electrical Meter and Service Equipment in Relation to the Antenna entry? Is it on the end of the house shown in the diagram or is it on the other end.

Is there any particular reason that you want to use a steel enclosure for your lightning arresters?

Will any other wire of any description enter your home through your grounding bulkhead. (That is the conductive metal panel of grounding busbar were you will be mounting your arresters.)

I ask these question because the answers have a large effect on the effectiveness of your grounding system.

--

Tom Horne W3TDH

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10 minutes ago, W3TDH said:

Jameson W3ESX

First let me introduce myself and provide a little of my background. I'm retired out of over 45 years in the electrical craft. I spent a part of my career installing communications shelters from Tierra Del Fuego up to Alaska and from French Frigate Shoals to Tucson Arizona area. The number of shelters I managed the installation of is over 100. The most important part of the installations was usually the Grounding Electrode System. Many of the shelters which I oversaw were self contained and self powered. Since that doesn't bear on your project I'll leave it there.

A Ground Rod is a Grounding Electrode. Three Driven Rod Electrodes spaced 2X their length apart, bonded to each other, and then connected to a Ground Busbar or cable entry bulkhead is a Grounding Electrode System. This leads to several questions.

Were is your Electrical Meter and Service Equipment in Relation to the Antenna entry? Is it on the end of the house shown in the diagram or is it on the other end.

Is there any particular reason that you want to use a steel enclosure for your lightning arresters?

Will any other wire of any description enter your home through your grounding bulkhead. (That is the conductive metal panel of grounding busbar were you will be mounting your arresters.)

I ask these question because the answers have a large effect on the effectiveness of your grounding system.

--

Tom Horne W3TDH

Tom,

We actually know each other! I was a member of MARC (you knew me then as KC3HKF) before I moved out to Baltimore and then to Detroit. We are back on the east coast now, and own a house up in Essex. I'm slightly out of the range of KV3B repeater, but that's one of the problems I'm hoping to correct by setting up this antenna.

Sadly, the electrical meter and service equipment is on the exact OPPOSITE side of the house as my shack. That is why I intended to drive another grounding bar. I hadn't originally thought that I would need to bond the two grounding bars together, but as I'm reading more of Grounding and Bonding for the Radio Amateur, it does appear that I should do that for safety's sake and to ensure common voltage.

As for the steel enclosure, no I had no particular reason for picking that other than that I saw a YouTube video with someone building a fully self-contained box with the lightning arresters and an internal ground bar and I quite liked the convenience and compactness of that design. This is the video. Are there any reasons NOT to use the steel enclosure that I am not considering? I will be the first to admit my electrical knowledge is lacking, but I am working to improve it.

As of this moment, the only wire that will be entering my home through the grounding system will be the coax. The coax will come down from the antenna, into the lightning arresters inside the box, and then coax coming out the other end of the arresters will go back up into my shack through a passthru panel. There is an additional "dedicated ground lug" on the passthru panel that I want to use that I will likely drop down from the panel and bond directly to the ground rod, but I'm taking it one step at a time.

Hopefully this clarifies some things.

Thanks,

Jamison W3ESX

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ELMER

FINALLY, a true expert in the field. @W3ESX you could not be in better hands than @W3TDH. I cede 😇

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