Grounding new shack..Ques/Advice

[osros]

I have read some of the other grounding threads but I have some simple questions and like to keep it simple as possible.

I will have a shack outside of the house in a barn, will start with a simple 20-30 foot mast all my equipment now is receive only HF and scanners, I plan to have surge protection and multicouplers, I'm not so much concerned about a strike but I want a good ground to lessen the noise. Here are my questions or concerns.

The shack will be grounded by electrician so assume he will use a ground rod (will instruct and make sure) Can i use this ground rod for all my grounding needs or do my own for Antenna and equipment ground rods?

If I go with a different rod should equipment and antenna ground be the same rod?
any benefit to using separate rods or needs to be the same? Or ground is ground it don't matter?

Does it matter what wire I use to ground with? wide stranded strap type or solid wire with cover? any recommendations?

I'm looking in the net all sorts of ground configs and wire setups photos, some cool looking some not so but the end result is the same, ground with a copper rod in the ground after that anything goes, preference.

Any links on ground rod accessorizes, clamps, plates, etc. Thinking of using some sort of plastic junction box with metal plate as central point for all surge protection, antenna connections with grounding.

 

[mmckenna]

I have read some of the other grounding threads but I have some simple questions and like to keep it simple as possible.

I will have a shack outside of the house in a barn, will start with a simple 20-30 foot mast all my equipment now is receive only HF and scanners, I plan to have surge protection and multicouplers, I'm not so much concerned about a strike but I want a good ground to lessen the noise. Here are my questions or concerns.

The shack will be grounded by electrician so assume he will use a ground rod (will instruct and make sure) Can i use this ground rod for all my grounding needs or do my own for Antenna and equipment ground rods?….
If I go with a different rod should equipment and antenna ground be the same rod?
any benefit to using separate rods or needs to be the same? Or ground is ground it don't matter?

Yes. National Electric Code says all your ground rods should be bonded together. You can add your own (or have the electrician install one at your shack, but it will be bonded to the one used for the electric entrance.

Does it matter what wire I use to ground with? wide stranded strap type or solid wire with cover? any recommendations?

Probably should use a minimum #6 for your main ground connection. Bare or insulated copper, doesn't matter. Straps work well, lower impedance. If the distance from your shack to your rod is short, then you probably won't need strap for RX ground.

I'm looking in the net all sorts of ground configs and wire setups photos, some cool looking some not so but the end result is the same, ground with a copper rod in the ground after that anything goes, preference.

Keep your grounds short as possible. Use proper lugs/connectors. For your mast ground, keep the run as straight as possible, short as possible, too. If you do have to make any turns, use gentle sweeping turns. Make it neat.

Any links on ground rod accessorizes, clamps, plates, etc. Thinking of using some sort of plastic junction box with metal plate as central point for all surge protection, antenna connections with grounding.

https://www.tessco.com/products/productHierarchy.do?tabId=32170
Harger Lightning &amp Grounding

Also, read the Motorola R56 document.

Alway assume your antenna/support will take a lightning strike. Lightning will do a lot of damage, even if it's not a direct strike. A fraction of an inch of insulation won't stop it. Remember, those lightning strikes travel thousands of feet to find ground. Your coax/radio won't even slow it down.

 

[AC9KH]

Well, equipment grounds, lightning grounds and RF grounds are three separate systems. As an example for RF ground, consider a quarter-wave vertical ground plane antenna. One wire of the feedline connects to the base of the antenna, and the other connects to ground. The connection to ground has to have a low RF resistance, or you'll burn up all your power heating the ground. A few radials will provide a decent low loss RF ground. A ground rod will do very little so RF resistance will be high, resulting in quite a bit of loss.

Another example for RF grounding is where balanced feedlines are used on multi-band dipoles with an antenna tuner and balun. At some frequencies there will be high standing waves on the feedline with thousands of volts and in some situations you can get "RF in the shack". The grounds on your equipment cases should in that case go to a ground rod and not be "daisy chained". But this is not an RF ground - it is an equipment ground.

Safety grounds for electrical equipment are covered by NEC or local electrical codes.

Lightning grounding is much more involved than the other two and not even the experts agree on what method should be used.

 

[osros]

Thanks!

A little bit more confused than before from the two posts on grounding together or not but will read over until I get it.

 

[jim202]

Thanks!

A little bit more confused than before from the two posts on grounding together or not but will read over until I get it.

Now that you have heard from all the self taught experts, you should really start back at ground zero. The first place that you should contact is your home owner's insurance company. Have them provide you with their requirements on grounding of antennas. They are the ones that will or will not pay for damage of a lightning strike.

Then try to obtain some information on what the NEC (National Electrical Code) says about grounding. There are several sections that deal with how grounding will be done. There is one section that deals with telecommunication sites and home antennas. The simple understanding is that you can add additional grounds, but that the other grounds need to be connected back to the electrical meter ground rod. Not all local electrical inspectors support this one section of the electrical code.

The big picture to look at is everything should be tied together (bonded) so if you do take a lightning strike, it all stays at the same potential. Damage occurs when you have a difference of potential (voltage) between different pieces of equipment (radios, antenna surge protectors, electrical surge protectors) and metallic objects.

You will read that you can't survive a direct strike from lightning. That is bull. Having come from over 20 years in the cellular and public radio field, if that was the case, every cellular company and public safety radio system around today would be off the air. You can strike proof your system, but it takes a big effort to make that happen.

Just grounding the metal pieces together isn't enough. It also takes installing a good electrical surge protection on the power coming in. You then add the surge protection on all the telephone lines. Don't forget that all the coax cables have to have their own surge protector.

The resistance of the ground system you put in needs to be as low as you can obtain. This takes multiple ground rods and good solid wire connecting it all together. You need to space your ground rods apart that is twice their length. This takes into account the cone of influence around each rod.

Grounding is a science and something that not that many people really understand. If you happen to be near a tower that just took a lightning strike, you will see the tower steam in the rain from the high current that just went through the tower legs. I have been there and then gone inside the equipment shelter and all the equipment is just humming away like it was before the strike. Yes it can survive a strike.

 

[prcguy]

Friends of mine in the insurance industry (manager of home claims for many states) say they have never denied a lightning claim due to home owner grounding additions or probmens. Its not on their radar and they don't really know what to look for.
prcguy

Now that you have heard from all the self taught experts, you should really start back at ground zero. The first place that you should contact is your home owner's insurance company. Have them provide you with their requirements on grounding of antennas. They are the ones that will or will not pay for damage of a lightning strike.

Then try to obtain some information on what the NEC (National Electrical Code) says about grounding. There are several sections that deal with how grounding will be done. There is one section that deals with telecommunication sites and home antennas. The simple understanding is that you can add additional grounds, but that the other grounds need to be connected back to the electrical meter ground rod. Not all local electrical inspectors support this one section of the electrical code.

The big picture to look at is everything should be tied together (bonded) so if you do take a lightning strike, it all stays at the same potential. Damage occurs when you have a difference of potential (voltage) between different pieces of equipment (radios, antenna surge protectors, electrical surge protectors) and metallic objects.

You will read that you can't survive a direct strike from lightning. That is bull. Having come from over 20 years in the cellular and public radio field, if that was the case, every cellular company and public safety radio system around today would be off the air. You can strike proof your system, but it takes a big effort to make that happen.

Just grounding the metal pieces together isn't enough. It also takes installing a good electrical surge protection on the power coming in. You then add the surge protection on all the telephone lines. Don't forget that all the coax cables have to have their own surge protector.

The resistance of the ground system you put in needs to be as low as you can obtain. This takes multiple ground rods and good solid wire connecting it all together. You need to space your ground rods apart that is twice their length. This takes into account the cone of influence around each rod.

Grounding is a science and something that not that many people really understand. If you happen to be near a tower that just took a lightning strike, you will see the tower steam in the rain from the high current that just went through the tower legs. I have been there and then gone inside the equipment shelter and all the equipment is just humming away like it was before the strike. Yes it can survive a strike.

 

[AC9KH]

The big picture to look at is everything should be tied together (bonded) so if you do take a lightning strike, it all stays at the same potential. Damage occurs when you have a difference of potential (voltage) between different pieces of equipment (radios, antenna surge protectors, electrical surge protectors) and metallic objects.

You might be able to survive close proximity or nearby strikes with consistent results. But direct strikes are a crap shoot, no matter what you do.

We got a wind turbine here on a 90 foot tower and that frickin thing gets hit, on average, twice a year. The tower (Rohn SSV) has elaborate ground rod and radial system that's supposed to dissipate the energy from a strike, but it don't dissipate all of it. Every single time it's been hit it blows the three-phase rectifier right out of the box, despite having the best lightning SPD's on the line that money can buy. The EA (Energy Absorption) on those SPD's is 4320 J with one on each line of the three-phase service coming from the turbine generator. The SPD's have an I peak of 100 kA and clamp is 1.29 kV. And the strike is never right on the stator windings in the generator - the leg current is produced by the EMF from the strike. Those SPD's will clamp it good enough so it only blows the rectifier and doesn't make it thru to the controller electronics. But there is only one way to insure no damage to your equipment from a direct strike, and that's to disconnect it from the feedline.

I've had the best people in the business here on lightning protection on that wind turbine, and no two of them have ever agreed on how to do it. And our insurance company don't even want to hear about it anymore when it gets hit.