A Ground Isn't Just Rods

[Kingrex]

I think lot of people have a misconception about grounding. They seem to think you add ground rods and that is grounding. What they don't recognize is grounding is a system. You have to get the ground from a receptacle to earth. And what is earth. Technically earth is also the utility neutral. If you walk the power lines at your house, you will see a transformer serves about 7 to 10 houses. Then the phase power wires are cut and tapes on the ends and hanging in the air. You will also notice the neutral/ground remains intact. They never break it. At every transformer you will see a solid copper #4 from the neutral/ground/transformer can to a rod at the base of the pole. In essence, all the rods in the entire utility distribution create a massive ground plane that is 0 ohms. Or very close. My clamp on resistance tester is designed around this. It injects a signal and in one direction knows the resistance is 0. That is the utility. In the other direction is the consumers ground and a math formula calculates what of that signal is getting into the earth in that direction.




So, back to you home. Your cold water pipe or Ufer is important for a number of reasons. But more important is how the connected wiring, the system wiring, from the receptacle gets back to where your cold water pipe and the utility ground are bonded. That is the magic. I had a customer with a very solid system ground from his receptacle to the utility, accidently break his house earth ground wire. And he heard no difference. I surmise the reason is the system is still seeing a very good 0 ohm ground in the utility system. I would not advise doing this as you're much less protected from surges and lightening anomalies. But your electrical distribution is still grounded.

I bring it up as I see people possibly hearing anomalies or not feeling they are at peak performance, and they think improving their grounding will help. Well, I agree, improving your grounding will help, but its not necessarily about adding grounds. Its more about assessing how your connected to your grounds.

To add a little bit of confusion to the equation, some grounds are better than other grounds at certain jobs. Rods, Ufer, Plates, Pipes, they react to voltage/ampacity/ frequency in different ways. Lightening, utility surges, motor induced surges and RF might shunt better to particular types of grounds. If you put a true lightening arresting system on a building, if the conducting wire from the antenna to earth turns parallel to earth for more than a few feet, or turn up, even slightly, the bolt will leave the wire and keep heading down through a different path. It will leave the wire. The wire is more a suggestion for the lightening. Its a set of sign post. But it is not the road. That lighting is going to go where it wants if it decides too. Its very unpredictable. I have been told RF acts a little like lightening. If you have a long run, parallel to earth or goes up and down and all over, you might pick up more noise than you shed.

Anyhow, its something I see people struggling with. And they may be getting misinformation on how to address it. Thanks for listening.

 

[Ron Resnick]

In a dry climate like Southern California with problematically dry soil what resistance to ground do you aim for?

 

[Kingrex]

Code is 25 ohms. Ideal is 5 ohms.

The only way to really know if your going to get there is a 4 point fall of potential test over many tracks of your property. The tool measures the resistance of the soil. The data from the tool is sent to a lab and the lab creates a grounding scheme that is guaranteed to get to some measure under 25 ohms you find acceptable. Maybe 2 chemical ground rods bedded in bentonite connected with 2/0 copper get you to 12 ohm. To get to 5 ohms takes 4 rods. To save money and fit the array on your land you settle on 2. 12 is still very good. 25 is still very acceptable.

My perception at these ohm levels is the way the wire is routed and managed from the duplex through any subpanels to the main disconnect/meter is more impactful than shaving a few ohms.

If your earth resistance is persistent at 300 to 800 ohms, you want to do something about that. But even then, bringing it down to 25 may not be a large sonic gain. Its definitely best practice. But you might not hear it in your stereo. I bet many people could lift the ground at their home and you may not hear anything change. But you are at more risk for surge events damaging equipment.

 

[microstrip]

In a dry climate like Southern California with problematically dry soil what resistance to ground do you aim for?

Ron,

IMHO it depends on too many aspects to have a formal answer. The first unknown is your system, the second is what type of mains ground wiring you have in your house, the third is the number and characteristics of appliances you have and the fourth is your mains noise.

Unfortunately the only parameter that is usually referred is ground resistance, that is relevant for safety and reliability issues. Ground impedance is the elephant in the room concerning high-end, but is never addressed.

 

[Ron Resnick]

Code is 25 ohms. Ideal is 5 ohms.

The only way to really know if your going to get there is a 4 point fall of potential test over many tracks of your property. The tool measures the resistance of the soil. The data from the tool is sent to a lab and the lab creates a grounding scheme that is guaranteed to get to some measure under 25 ohms you find acceptable. Maybe 2 chemical ground rods bedded in bentonite connected with 2/0 copper get you to 12 ohm. To get to 5 ohms takes 4 rods. To save money and fit the array on your land you settle on 2. 12 is still very good. 25 is still very acceptable.

My perception at these ohm levels is the way the wire is routed and managed from the duplex through any subpanels to the main disconnect/meter is more impactful than shaving a few ohms.

If your earth resistance is persistent at 300 to 800 ohms, you want to do something about that. But even then, bringing it down to 25 may not be a large sonic gain. Its definitely best practice. But you might not hear it in your stereo. I bet many people could lift the ground at their home and you may not hear anything change. But you are at more risk for surge events damaging equipment.

Thank you.

 

[Kingrex]

Microstrip said about the same thing I did. He just used more technical terms.
Its all about the wiring, the noise from the utility, the noise from your house.

If you have all that right, it is my belief the actual ground resistance is is less important.
If something is wrong, parasitic noise (stray voltage on the ground/neutral) may not shunt to earth as easily and the ground resistance may matter more.

I'm pretty confident you wired very well during your remodel. I have not seen it, but from what you have told me, it does not have glaring issues. You would probably get more gain by eliminating all aluminum in your system. I am confident you have some around. Its maybe a small amount, but you can definitely hear aluminum as a more closed in, slightly muffled presentation. If you have a very bright system, this might be something you like. If you have an articulate system you want to sound as natural and alive as can be, you have to get rid of the aluminum. You have to focus on pure copper, effectively bonded wiring materials. If you have horns, we need to talk about branch circuit conductor materials.

 

[DonH50]

Grounding can be tricky. Just adding a ground rod or five might not help your system, and may even make it worse. Your system cares about the local ground potential and limiting ground loops (which adding extra rods can actually create, making it worse). If all the components are at the same "ground" potential you are usually fine as everything "moves together". Obviously if the potential is too high that is a problem, both for noise and safety, but that is rare IME. Adding a low-ground potential at one point in the system may force all ground currents to flow that way, which can "unbalance" the ground potentials of your components and cause more noise.

Example: Once upon a time after a lot of troubleshooting I added a couple of ground wires to a system, basically chassis-to-chassis heavy copper braids, that eliminated a ground loop and helped resolve an interference (noise) problem. The wires connected some components in my rack, like preamp, TT, and processor (analog EQ), without touching the power amp that was off in a corner. Later I decided the thing to do was to add a nice "earth" ground rod outside and connect it to the system. I purchased and installed a good 8' (~2.5 m) rod outside the room, running a heavy wire through a wall channel hidden in the corner connected to the power amp that was right there. The ground buzz came back with a vengeance, as now the carefully routed local ground scheme in my rack was subverted by the new lower-impedance path through the interconnects to the power amp and out to the rod instead of the wall outlet's safety ground. Oops. Disconnected the rod and all was well again. Running the wire over to the rack worked in the sense that it did not cause noise, but nothing I heard or measured indicated it helped anything, either. I pulled the rod and relocated it to my Ham radio station and antenna tower where, if it didn't help much, at least it did no harm. Hopefully it provided a lower-impedance ground for the lightning arrestor on the tower.

FWIWFM - Don

 

[Kingrex]

Grounding can be tricky. Just adding a ground rod or five might not help your system, and may even make it worse. Your system cares about the local ground potential and limiting ground loops (which adding extra rods can actually create, making it worse).

True

If all the components are at the same "ground" potential you are usually fine as everything "moves together". Obviously if the potential is too high that is a problem, both for noise and safety, but that is rare IME. Adding a low-ground potential at one point in the system may force all ground currents to flow that way, which can "unbalance" the ground potentials of your components and cause more noise.

True

Example: Once upon a time after a lot of troubleshooting I added a couple of ground wires to a system, basically chassis-to-chassis heavy copper braids, that eliminated a ground loop and helped resolve an interference (noise) problem. The wires connected some components in my rack, like preamp, TT, and processor (analog EQ), without touching the power amp that was off in a corner. Later I decided the thing to do was to add a nice "earth" ground rod outside and connect it to the system. I purchased and installed a good 8' (~2.5 m) rod outside the room, running a heavy wire through a wall channel hidden in the corner connected to the power amp that was right there. The ground buzz came back with a vengeance, as now the carefully routed local ground scheme in my rack was subverted by the new lower-impedance path through the interconnects to the power amp and out to the rod instead of the wall outlet's safety ground. Oops. Disconnected the rod and all was well again. Running the wire over to the rack worked in the sense that it did not cause noise, but nothing I heard or measured indicated it helped anything, either. I pulled the rod and relocated it to my Ham radio station and antenna tower where, if it didn't help much, at least it did no harm. Hopefully it provided a lower-impedance ground for the lightning arrestor on the tower.

You need to be careful here. 2 grounds bonded at 2 different points in your electrical system as you have seen with audio can cause issue. It also means a lightning bolt to earth near your home is going up 2 ground sets to 2 different points in your electrical distribution and its at different voltages. This can create a strange swirl of hundreds of thousands of volts through the ground system of your home. You want these systems isolated from each other. I am not sure how to do this since there is 1 service. Unless your battery with the radio, and the charging power cord is unplugged during lightning events. The last ham radio I did I brought a #2 from a 1/4" x 2 x 8 bar at the radio station to the ground system in the main panel.

 

[Atmasphere]

@Kingrex The real issue here is how the audio system is affected. If the components in the system are designed properly (IOW how well their internal grounding scheme is designed) then the house grounding system really won't have any effect other than safety and storm issues.

Remember that amp you sent to me to get rid on the buzz and hum it had? That was all about fixing its grounding scheme. There are of course limits to what you can do to fix obvious mistakes made in things like that; if you start from scratch and get the grounding done properly from the ground up (if you see what I did there) then the house electrical ground will have almost no effect on the system at all. Plus those 'grounding boxes' that you read about won't have any effect either. Its weird that here in the 21st century grounding is still the Wild West in high end audio.

 

[Kingrex]

@Kingrex The real issue here is how the audio system is affected. If the components in the system are designed properly (IOW how well their internal grounding scheme is designed) then the house grounding system really won't have any effect other than safety and storm issues.

Remember that amp you sent to me to get rid on the buzz and hum it had? That was all about fixing its grounding scheme. There are of course limits to what you can do to fix obvious mistakes made in things like that; if you start from scratch and get the grounding done properly from the ground up (if you see what I did there) then the house electrical ground will have almost no effect on the system at all. Plus those 'grounding boxes' that you read about won't have any effect either. Its weird that here in the 21st century grounding is still the Wild West in high end audio.

I agree to a point. The ground in the earth being lifted might result in 0 audible change.
But, the way the grounds and neutrals of everything in the electrical infrastructure from the service, feeders, branch circuits, how those are adressed can have a profound influence on what you hear. And I am not taking just size.
Its a way overlooked aspect.

The ground in the earth is very necessary for safety. And as far as I know, is very important to your surge protective devices to work properly.

 

[Atmasphere]

But, the way the grounds and neutrals of everything in the electrical infrastructure from the service, feeders, branch circuits, how those are adressed can have a profound influence on what you hear.

Again, that's only if the internal grounding scheme of your equipment is compromised in some fashion. The fact you hear that is telling you something!

 

[Alrainbow]

Ralph ur both right , but most devices benifit from good grounding power anyway

next the issue beyond fixing internal grounding is the variables from and to each device and there varying ground potential

why , who and little use of input transformers for signal
Your around forever. when and why did this stop or rally used now ?

 

[Kingrex]

Again, that's only if the internal grounding scheme of your equipment is compromised in some fashion. The fact you hear that is telling you something!

Thats not my experience over many system. Especially when you consider the neutral. That is a very active component in the power chain.

And I can measure clear voltage potential differences in a circuit when the circuits tied to audio are optimized.

I can measure voltage potential differences around the neutral and ground bus in most all loadcentsrs.

Here is a very typical panel I see all the time. I see a few issues that if changed, will generally result in a felt calm and better integration of drivers. If you only want to talk technical, it will measure lower impedance and have less rectification. Rectification is usually caused by dissimilar metals such as aluminum / copper junctions which then rectify the RF in the air and add the resulting modulation voltage to the power line. These are measurable events that as a best practice should be eliminated from the power delivery system.

 

[Atmasphere]

Thats not my experience over many system.

How did you know that the internal grounding scheme of all the equipment in those systems was correct? If just one piece gets it wrong all bets are off.

 

[Kingrex]

I dont know how well equipment I have been in front of this last week is built. I assume its good. Yeaterday I moved a neutral feeder on the bus from a location that had 9.8mV of potential between it and the utility neutral. In the process I removed the neutrals reliance on aluminum as a contact.. I asked everyone to be honest in their perceptionof any change, if any at all. I need to know the truth. Everyone heard it. Including myself. It impacted all 3 system I heard. It actually made it much more comfortable to have the music as background while we talked. It flowed. It was tighter and more controlled, but relaxed.

 

[Kingrex]

I have been out of state looking at infrastructure this week. This is very typical of what I see on multi million houses with $500k and up systems.

 

[MarkusBarkus]

...and you know the connections and terminals in that meter are an abomination too. Sobering pics for audio folks with expensive systems, cables and "ground boxes."

 

[Alrainbow]

Most think grounding good or bad is related to only hum
what you do shows how the sound itself becomes more musical

as an example a server befits from grounding it does not hum but it sure kills the music of issues are around it.

some audiophiles look to isolate the streamer to the dac
but how it’s done and if it needs to be is more complex then a optical cable
good grounding is a must first

then try alt methods

 

[Atmasphere]

I dont know how well equipment is built.

Well now you have a metric. If you hear changes doing things like you are, its a tell that the internal grounding scheme of some piece in your system isn't up to the task.

 

[Kingrex]

Well now you have a metric. If you hear changes doing things like you are, its a tell that the internal grounding scheme of some piece in your system isn't up to the task.

Being so adamant about the neutral and ground having no bearing on sonics if the equipment is built well, what is your take on music sounding better when all equipment is on the same phase? Is this an equipment power supply issue.