How do I add lightning protection for me feed lines

[Anthony Rizzolo]

I am adding Lightning protection for my feed lines.  Here is currently what I am doing:

 

1. I went to Home Depot and purchased an 8′ grounding rod (that seems so long when you have to put it into the ground!)

2. I went to HRO and purchased a bracket to attach to the rod and the ground suppressor.

Here are some questions I am wondering about:

So now I need to put the rod into the ground.  Is there any hard and fast rule about how close to the house I should place the rod?  Can I put it under my deck.

I believe that I need to seal the wires against water but I was also told that I need to be able to disconnect the wire outside the house.  What is the best method to do this.

The place where my antenna comes into the house is on the opposite side from the ground that the electric company has for the electricity.  How important is it that I connect to the common ground.

Also, the ground for the radio would need to be in the front of the house since I don’t want that going the 100′ that the feedline takes to get to the shack?  How important is that ground?

 

[Nashua Area Radio Society]

Hi Tony,

Where was this question last month, when I was doing mine.

 

I put put my ground rod about 3-4 feet away from my house.  To sink the ground rod I used a water drill which worked really well and is very easily constructed for less tha $20.  Here is essentially the model I used.

http://youtu.be/-kpI8PFNYl4

Attached to the ground rod I have a Z  bracket (the thing you got at HRO) with two lightening arrestors, one for my vhf, and one for my hf antennas, I also have my #6 solid copper wire which I have run to the ground bar of the AC panel inside the house.  Like you my AC main ground is a long way from the shack entrance.  It is important to ground your lightening protection to your AC main ground otherwise one day you touch something and you become the element that completes the circuit- not a good outcome.

For RF grounding, I use separate 1/2 inch braided copper to  a 4′ length of 3/4″ copper pipe from each of my components attached with hose clamps.  Then 3/4 inch copper braid also attached with hose clamp to just before the exit of my house where I have joined it to #2 heavy gauge stranded copper out through the wall and to the ground rod.

I will upload pictures when I get home this weekend.

Like you at the Tech Night, I struggle with disconnecting the feed lines outside of the house, how do I keep my coax from getting wet?  I waterproofed the connections the best I could at install with the rubberized coax tape and electrical tape, which completely covers the attachments on both sides of my lightening arrestors, hoping this would be a somewhat permanent connection.  I don’t relish the idea of doing this everyday.  I do however unplug the feed lines from my gear inside the shack.

The correct answer, of course,  is to unplug outside, but I wonder how many folks really do that?  I would welcome comments on that point with the full understanding and acknowledgement that this is merely an expression of what others do, and in no way advice on how I should proceed!

I mostly followed Fred’s  (AB1OC) article when planning, any errors in implementation were mine…

73

Greg

 

[Fred Kemmerer]

Hi Tony,

If you can use the same ground rod for your feeling and your radio, then having the rod close to you house so that the ground connection between the rod and your radio is as short as possible.

I would suggest putting a small water pale over the top of the rod/suppressor to protect the connection that you can disconnect. If you disconnect your feed line and separate it a bit from your ground when not in use, then its not as critical to bond your radio ground to your electrical service ground. What you are trying to prevent here is a situation where lightening hits your antenna, follows the coax to your ground and then to your radio. Once the lightening gets to your radio, it will find a path through it and your house to the electrical service ground. The energy in lightening is very intense and it would  certainly destroy your radio in this situation and could easily start a fire in your home.

So what we need to prevent is the lightening from coming into your house through the coax or the radio ground. There are two ways to do this:

1) Disconnect your feed line on the antenna side of the arrestor and more the disconnected coax WELL AWAY from your house or

2) Properly bind the radio/coax ground rod to the electrical system ground at your meter

 

Doing #2 is difficult because the path that you create via binding must be so much better than the one through your radio/house that lightening will not go there. When I did mine, I used buried 00 gauge cable, avoided any sharp bends, and drop 10 ft ground rods every 6 feet or so and connected those to the bonding cable a it made its way from my radio/coax ground to the house electrical ground.

For a basic station like your, I think that #1 is much easier.

Also, you should properly seal all of your outside connections with coax wrap + electrical tape except the one that you will need to disconnect.

I hope that this helps.

[David Merchant]

Greg,

I completely agree with Fred. However, I will add that you must be very disciplined if you go with option #1. Speaking from experience, it’s very easy to forget to disconnect the antenna feedline. Also, there may be times that you intentionally leave it connected thinking there won’t be any storms. For example, you may think you’re safe during the winter months, but you can still get thunder snow.

I have a weatherproof enclosure outside my house which contains my lightning arrestors. DX Engineering carries one here:

http://www.dxengineering.com/search/product-line/dx-engineering-utility-enclosure-kits?autoview=SKU&keyword=Enclosure&sortby=BestKeywordMatch&sortorder=Ascending

I have a similar enclosure and ran copper strap between the enclosure and my service entrance.

Being on the top of a hill, my house also has lightning rods and a perimeter / halo ground system. This is bonded to my service entrance as well. Even with all of this, I’ve experienced lightning damage 5-times in 9-years to various systems in the house. Luckily, I’ve never had a problem with any of my radio equipment.

If you’d like to do some reading om the topic, here are a few articles and publications:

(1) http://k9yc.com/GroundingAndAudio.pdf
(2) The holy grail on grounding

“MIL-HDBK-419A “Grounding, Bonding, and Shielding for Electronic Equipments and Facilities”   9.6 MB PDF file dated 29-DEC-1987
This is the big military handbook on grounding. It is large, in two volumes totaling about 812 pages. Volume one is 396 pages of theory, volume two is 394 pages of practice. This download is the complete 2 volume set in one PDF file, and volume 2 starts on page 419 of the PDF file. This book covers grounding for safety, lightning, nuclear blast and most everything else. A very good read and a real eye opener. This handbook is approved for public release and distribution is unlimited.
At one point (Feb 1999), the hardcopy (including postage) was FREE if you ordered it from:
Commanding Officer
Naval Publication and Forms Center
5801 Taylor Avenue
Philladelphia PA 19120″

73,

Dave
K1DLM

[Anthony Rizzolo]

Thank You Greg, David and Fred…I will check out those posts…

Fred, I assume that I want the actual rod as close to the house as possible so the there is not that much length or is 3-4 ft away a good distance.    By well away from the house are we talking a couple of feet?  Also, what keeps the lightning from hitting the ground rod and going through the wire that is still coming into the house or can that just not happen…

I’ll probably try to get this in the next couple of weeks…I have all the pieces now (the grounding rod from Home Depot and the lightning arrestor and clamp from HRO so its just a matter of find the time to install it.

Thanks to everyone for all the comments and sorry it took so long for me to get back to the forum to respond.
Anthony

[Fred Kemmerer]

Hi Tony,

Driving the rod into the ground 2 – 3 ft from the house is a good distance. When you disconnect you coax, you’ll want to get the end well away from the rod as you suggest.

[Nashua Area Radio Society]

Along the same vein of conversation:

Greg, I looked up the Alpha-Delta arresters you use: They allow DC voltage through. In Fred’s blog, the PolyPhase ones block DC. So my question is which is the better investment? Like all things, I am betting the answer is “it depends”, but I’m looking for the caveats following that statement.

The only thing I could think regarding why you want to allow DC through is if one has some antenna switching setup that sends a control voltage to the outside box to switch the ports. I don’t know if that is typical in practice to encounter, however.

The price point between the Alpha-Delta and PolyPhase isn’t enormous, so I’m really just curious about which ones seems best for just getting started. As a sidenote which may be helpful, I may have 3 antennas (maybe 4) by the end of the summer.

Thanks for all help and 73,

Brian

[Nashua Area Radio Society]

Along the same vein of conversation:

Greg, I looked up the Alpha-Delta arresters you use: They allow DC voltage through. In Fred’s blog, the PolyPhase ones block DC. So my question is which is the better investment? Like all things, I am betting the answer is “it depends”, but I’m looking for the caveats following that statement.

The only thing I could think regarding why you want to allow DC through is if one has some antenna switching setup that sends a control voltage to the outside box to switch the ports. I don’t know if that is typical in practice to encounter, however.

The price point between the Alpha-Delta and PolyPhase isn’t enormous, so I’m really just curious about which ones seems best for just getting started. As a sidenote which may be helpful, I may have 3 antennas (maybe 4) by the end of the summer.

Thanks for all help and 73,

Brian (AB1ZO)

[Benjamin Martin]

Hello all,
I searched through many forum posts and haven’t found answers per se:

I’m in the process of building my lightning protection system (and feedline entry) and have two lightning arresters in a waterproof enclosure at my feed entry (which is conveniently located next to house electrical feedpoint/service meter, etc.) – one for VHF/UHF antenna and one for HF vertical.

Two questions:
1) The MFJ lightning arrester I’m using is too small to take the gauge of solid copper wire I was planning to use to connect to the ground rod. I want to say it was #6 or #8 (have to check), so I’m wondering what AWG is really necessary for the arresters if the crimp connection is smaller than #6 (or #8 – again, have to check on which size wire I have).

2) The electrical outlet I’m plugging my radio into (or rather I’ll be plugging my radio into a surge protector plugged into that wall outlet) is grounded, and is a 20 amp 12 ga house electrical wiring circuit. In addition to this electrical connection being grounded, I was planning to run a wire from my radio ground (ground screw on back of radio) to a common ground outside where I will have the house ground and lightning arrester-attached ground rod connected together. I was planning to use something simple like 12 AWG stranded copper wire between my radio ground and this common ground (in effort to connect as many things to ground as possible) but is 12 AWG heavy enough for this specific ground wire?

Thanks and 73,
Ben – W1BPM

[Benjamin Martin]

Hello,

I’m in the process of building my lightning protection system (and feedline entry) and have two lightning arresters in a waterproof enclosure at my feed entry (which is conveniently located next to house electrical feedpoint/service meter, etc.) – one for VHF/UHF antenna and one for HF vertical.

I have two questions:
1) The MFJ lightning arrester I’m using is too small to take the gauge of solid copper wire I was planning to use to connect to the ground rod. I want to say it was #6 or #8 (have to check), so I’m wondering what AWG is really necessary for the arresters if the crimp connection is smaller than #6 (or #8 – again, have to check on which size wire I have).

2) The electrical outlet I’m plugging my radio into (or rather I’ll be plugging my radio into a surge protector plugged into that wall outlet) is grounded, and is a 20 amp 12 ga house electrical wiring circuit. In addition to this electrical connection being grounded, I was planning to run a wire from my radio ground (ground screw on back of radio) to a common ground outside where I will have the house ground and lightning arrester-attached ground rod connected together. I was planning to use something simple like 12 AWG stranded copper wire between my radio ground and this common ground (in effort to connect as many things to ground as possible) but is 12 AWG heavy enough for this specific ground wire?

Thanks and 73,
Ben – W1BPM

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