I'm going to put my radio bench in my workshop.  It has a small breaker panel and is fed from the main house panel by #3 wire I think.  I started looking today and there is no ground stake outside nor is there a ground wire aside from the one bundled with the main supply.

I guess I need to put a ground rod outside on the corner and wire it to the ground bar in the panel?  All this was here when I built the house.

You should always refer to your local codes for an external building. But generally a ground rod is required for a sub panel in an external building. And the neutral and ground bars should not be bonded in a sub panel


Not an electrician.

NEMA codes are for safety, but a ground lightning strike will build a potential between two bonded but widely separated rods.

I’m not a radio buff but is it safe to assume that transients are your enemy?

Multiple grounds are more transient friendly (in 7th and 13th wave if I remember correctly).

Personally I’m a fan of duel grounds within feet of each other and bonded at the rods (single ground wire).

So if your in an area where code is enforced it’s best to ask a local electrician.
If your in da boonies we do what makes sense. (theoretically of course)

I would agree with this .
I have heard mixed reviews on this. I personally will not run separate ground rod for shed.
Electrical energy always wants to return to the SOURCE. Not ground. It will use ground to return to the source (not necessarily good).
There are videos on this.

I'm in a rural area so it's the state codes that apply.

I was going to put in a grounding bar for the radios so I guess I'll run a ground wire to the bar in the panel?

Do you have four wires coming into the sub panel or three?

If it's four you should unbond the ground and neutrals. Otherwise power can return to the main panel on the ground wire. Add at least one ground rod outside and connect to the ground bus in the sub panel. Code says two ground rods separated by 8 feet but it's not really clear to me why that's necessary

Also not an electrician

This video does a good job of explaining 'why':

In before people come in and say they never ground anything.

https://www.w8ji.com/house_ground_layouts.htm

I grounded my station equipment to copper bus bar near where my coax comes into the house, then ran a fat copper wire from the bus bar to the outside and put that on an 8' ground rod driven into the ground, then ran more fat copper wire (with more ground rods along the way to where the power went into my house and tied to the ground in the main breaker panel (a licensed electrician made that last connection for insurance purposes).

Where my coax comes into the house, I have a "lightning arrestor" it passes through that is also grounded to the 8' ground rod.

I looked at the sub panel and there are four wires coming in.  I don't see anything connecting the ground bar with the neutral bar.  Or is that something I'd find in the main panel?

There are 3 different grounds you have to consider and it gets more complicated with more than one building.
Electrical
Lightning
RF


Electrical:
Your seperate building needs a ground rod at the panel connected to the ground bus. Inside the panel the ground and neutral should not be connected. Usually it is what is called a bonding screw on the neutral bus. There should be no bonding screw. Your main house panel should be using the bonding screw to connect neutral and ground. This main panel is the only panel that should be neutral bonded. It would be nice if house and outbuilding panel ground rods were connected with 2AWG wire.  Doing this to achieve as little  ground potential difference as possible. Lightning acts like an amplifier of sorts. A small potential difference in grounds becomes a huge potential difference during a lightning event.  

Lightning:
You need to instal a ground rod where you intend for the coax to enter the building. This is where you will install you lightning protection devices. I am a huge Morgan fanboy. Reason why is they are DC grounded devices and do help eliminate some noise from static build up and crashes. For a simple antenna system you can simply mount your devices directly to the ground rod.
Excellent source of quality equipment to do the job:
https://www.kf7p.com/KF7P/Products.html
This ground rod should be tied to the building panel ground with 2AWG wire.  For the same reason as above.

RF:
Each piece of equipment in the shack should be chassis bonded to a common ground point. Do not daisy chain chassis grounds. Each item should have its own ground to a common point. This common point should be connected to the Lightning ground rod. Again it should be heavy gage wire. No braided wire grounds. They can become inductive.  


What I have described is for a simple system that might be used with a single mast mounted antenna or wire antennas. With towers and large metal structures it becomes more complicated.


2 Ground Rods Spaced 8 feet Apart:
The reason some code departments require 2 ground rods mounted 8 feet apart is because poor ground conductivity in the local area. You can consider a ground rod as a semi sphere of conductivity. If it is an 8 foot ground rod is fully installed in the ground it forms a semi sphere with an 8 foot radius below ground level. So in areas with low ground conductivity they say 2 8 foot ground rods spaced 8 feet apart. This overlaps and expands the ground conductivity area. They can actually be spaced 16 feet apart but they will not achieve as much ground conductivity.

Lightning is not a DC event. It is AC and is looking for low impedance to ground. Ground systems should be low inductance and capacitance so that the increased charge voltage can be quickly and as soon as possible directed to ground.

It should ONLY be in the main panel. Never bond neutral anywhere else.

Usually a green bonding screw inside the panel.


The second 8’ ground rod was added as some soils don’t have enough conductivity to dissipate what the engineers wanted.   There is a machine to test that conductivity but it is stupid expensive.   Using it and verifying the ground’s adequacy you can do just one rod.....or just install a second $12 rod and a continuous loop of bare copper connecting them and the panel.  

Not an expert by any means.  I was going round and round on this in a second structure, my new garage whether to be bonded in that box or not.  


normally you have pole, house meter and run out to second building from the house panel.

Mine is pole with my shutoff meter on it which is considered my main, then my service runs a tenth of a mile to my last pole and my house and garage are each drops from my pole.  Basically like farm building or a commercial multi building complex electrical drops.  I had sparkys argue with each other whether my garage gets the green bonding screw or not.

So lets get this correct. You have you meter base and a panel with nothing but mains breaker in it feeding both house and outbuilding. I assume each in also on it own breaker in that same panel? If that is the case then the ground and neutral must be bonded in that panel and the panel in the house and outbuilding, the neutral should NOT be bonded to ground. First panel after leaving utility drop or pole.

ETA, I did not fully catch all the aspects of your question.  To clarify, no the cut off switch in the panel at the meter by the road feeds one common overhead line, basically I run my own overhead power service line is how the po co lineman described it.  The two structures although are served by the same meter are like individual structure owner drops.  

(Partially) Correct, just off the road the service line comes down my first pole the a meter and locked main switch and back up the pole, goes in the air three more poles up my hill.   At the top of that pole, there is one run that goes underground to the house and another underground about 8’ from the pole added later to the garage.  

House was built around 2005, garage was added around 2013.  


IIRC my bonding screw is laying in the bottom of my garage panel unused.  I would have to pull the panel cover off the house panel to check that one.   Maybe I misremember,....maybe they as such had them both bonded.   I have what appears to be three wire service on my poles, two hots, one neutral.    



ETA, may not be a breaker at the road, it may be a shut off only.

Yeah that strange for sure. Wonders why meter wasn't mounted to the house. I for sure would be calling someone before ever digging close to where the runs are.

Lots of info to consider there.  I live in a very rocky area so getting a 8 foot rod in the ground is going to be fun.  I tried it in a different spot in the yard (several years ago) and I only got down about three feet.

Then you will need more rods. Go buy a cheap demolition hammer drill from harbor freight. Find appropriate ground rod driving bit that fits your drill. Beats the hell out of a sledgehammer.

easy answer,.....responsibility.

The power company didn’t wish to own the poles from the road to the house.  Then they would have to maintain it before the meter.   I own at least three poles, maybe the fourth with the road shutoff affixed to it too.

I made my own driver for my bigger corded SpS+ hammer drill.  Harbor fright cheap SPS demo bit set, cut off one of the chisels just for the shaft slipped on a piece of power steering hose and secured it with a small hose clamp.   Slip ground rod in open end of hose and the cut off shaft inside hammers it.  Drive a rod in soil in about thirty to forty seconds,.....if you don’t have big rocks or bed rock to stop you.  You can prospect around to find a way past big rocks, if it’s nothing but bed rock it’s time to angle the rod sideways.   Certainly not as good as a deep set rod.  I got about four or five feet of dirt before hitting shale with bands of limestone.  Pulled them back out and searched out the deepest angle I could get the whole 8’ sunk.

I rented a big nasty one from Home Depot. $75 for the day. Had the cup end for ground rods. I sunk 3 ground rods in almost no time at all.

You can also put them in horizontally. Can't remember the depth but they still have to be 8' apart

I had to do that at my last shop. There was a layer of hard pan about 3' down that was like cement, even a large rotohammer with a rod driver couldn't get through it. Dug a trench ~8' long and drove one rod one way and another the opposite

The duplex I'm working on currently is set up like that. 200A main breaker right under each meter base (both on the side of the building) then there are traditional panels inside for distribution that are really sub panels. The neutral and grounds were bonded but they shouldn't be

Haven't seen a good explanation for why it was done like that. The building is almost 100 years old and has had many changes over the years

Nevermind - already answered.

Ok, I'll be working on the ground rod, either vertical or horizontal.

I  know that solid copper wire is used for that connection, where is the braided copper used?  Between the radio and grounding point?  I have a grounding bar that will mount to the wall behind the desk for all the equipment to be grounded to.  No daisy chaining here.

With a bolt or near bolt, the DC-RF will go into the ground ,if like you say, the impedance to ground is lower than any other path to ground.

The problem arises when the ground tries to absorb the strike or near strike, the energy feeds into the ground and since the energy is enormous and very fast the ground around the ground rod acts like a capacitor and builds a stored charge as the energy can not dissipate in the ground as fast as it gets dumped into the ground rod, and then when it is no longer the lowest impedance to ground, it finds another path and jumps to that path.

That is why it normally takes an acre of ground rods spaced at 16 feet apart all connected with large wire / pipe to dissipate a direct strike. That is how much ground is needed to dissipate a direct strike and still keep the ground system at the lowest impedance path to ground.

6awg stranded or 6 awg solid copper is acceptible for connecting the rod but as far as I have been told the stranded has more surface area and can let E flow better.  

inside between the radio and the bar I have coated copper braid straps.  It is what I could find but bare copper flat straps is best recommendation.

Since you brought it up, I will add to what I posted earlier. This will be focused entirely on lightning protection and grounds. Most of what I posted earlier was about building structures. What you posted is correct. Lightning field decay time can be very long when compared to rise time. To dissipate lightning quick enough does require a lot of ground space. Basic rule to follow is the height of the structure is the radius on the ground to be the ground system. Tall antenna structures such as ground mounted mast that are taller than existing structures and tower require some serious grounding. Typical tower systems require a minimum of 3 ground runs the length of the tower height with 8 foot ground rods spaced 8-10 feet apart with each run connected to a leg of the structure. A ground ring around the base of the tower connecting the 3 runs. One of the 3 runs must be tied to the main or sub panel ground if using separate building structures.

Some may say an ufer ground is sufficient as that is what power companies do at the base of power poles that have mounted transformers. I am not going to agree or disagree with that as I am not that knowledgeable on Ufer grounds. I will say that if you wish to bury a coil of copper wire in the ground under the tower base, go for it. It isn't going to hurt. I prefer to bury it in the ground and run it so that it is outside the concrete base not thru it.

There is some disagreement about running grounds thru concrete. Some say it will causes the moisture in the concrete to heat and crack the concrete. Others say it causes no problem. I say don't do it because the concrete will corrode the copper and you will lose the effectiveness of the grounding. Concrete is hungry for copper minerals. You have a big hole, so coil the copper wire, cover with dirt, and notch the hole so you can pour the concrete so that the copper doesn't touch concrete.

With all that said, do most amateur radio operators follow those guidelines? Certainly not! Does not doing this way work? Yes but you are playing the lottery. Eventually there will be that one lightning scratch off that wins you the jackpot of burnt junk.

For RF grounds, while there is a difference in inductance between copper strap and a braided grounding strap of similar dimensions, it is not a very big difference, and the braided strap is so much easier to work with. I recommend you get some 1" braided strap and a whole bunch of mechanical lugs like this:

Attached File


Roll up each end of the strap, jam it in the lug, and Bob's your uncle.

Attach the other end to a long piece of drilled and tapped copper grounding bar, or make your own bar out of some copper plumbing pipe.

For safety grounds, or lower performing RF grounds, 6AWG insulated stranded is easier to work with than solid, and even easier still is 6AWG "welding cable", which has a very high strand count so that it's very flexible. Again, the mechanical lugs make terminating these connections so very simple.

My entire station lives in 7 foot tall rack with a full height copper grounding bar. Every single component that can be is grounded to that bar with braid except for some of the smaller stuff like Ethernet switches or whatnot, those just get some 10AWG stranded.

I have to admit my game is a little weak after that. I use 6AWG welding cable to go from the copper bar to a ground rod outside about 15 feet away. I probably should use strap. But my antenna lightning protection is good: Morgan arrestors mounted on a Morgan bracket directly to the top of that rod.

I do not bond that RF/lightning protection system to my main electrical service ground. It's just too far a run, something like 150 ft. If I ever get to design a new QTH I will be certain to plan for that. But mostly I just wanted a really good RF/lightning protection setup. As a result the number of ferrites and other RF control band-aids in my station is zero except on one Ethernet line, which I am currently working to replace with fiber. I have lost two Morgan units to lightning in the last 10 years. I'm sure nothing will stop a direct strike, I don't live in a metal building built to the Motorola R56 standard (so few of us do! )

Yes the Godfather of station design manual. R56 is great source of information. Most of it is a 1000 times overkill for stations like an average ham. There is a some great information in it that can be applied to building a station.

Another great source of information is a book on grounding and bonding as it applies to ham radio:
http://www.arrl.org/shop/Grounding-and-Bonding-for-the-Radio-Amateur-2nd-Edition/

This is all great info guys!  Now if the temps would get above freezing.... LOL

This is incorrect.  Two ground rods 8' long spaced 8' apart will have overlapping ground coverage i.e. the area of the overlapping 8' diameter circles.  Two 8' ground rods spaced 16' apart will each have two non-overlapping circles of 8' diameter each.  No overlapping = greater ground conductivity.

Braided copper should only be used in interior spaces, not out in the elements.  I'll find a QRZ thread discussing this shortly and post it here with more discussion and pics.



ETA:  Here is the QRZ thread discussing this very topic:  https://forums.qrz.com/index.php?threads/grounding-braid.796937/

Great, thanks!

Which HF SDS hammer drill?  The $109 or the $199 and up versions?  The ones I've seen used on YT are pretty big units.