[Syrah]

I've always comtemplated the idea of installing a second ground rod, as studios do.  My yard has very rocky soil, so i was thinking of a horizontal chemical ground.

Then i remembered that I have a 20 foot deep well that was dug for gardening water.  I don't use it because apparently the water is saline.

Would a copper rod sunk into a saline water well not make a good second ground?

It's not soil.  Do people living on the ocean use the ocean as a ground?

My thinking is to bond that second ground to my main earth ground, which is an exposed copper pipe sticking out of one corner of my driveway.

Thanks for any help.

[Syrah]

Sorry, a follow up.  Does one test the quality of a ground by using a voltmeter and measuring the hot to ground voltage?  Is the higher that voltage the lower the ground resistance?   If so, the answer to my last question would be easy for me to test.

Thanks again!

[paul79]

You have to connect secondary ground rods to the main. No choice there.

As for using the high saline content earth as ground, I am not sure about. I'm sure more in the know will be around shortly.

[S Clark]

Saline water is like having a copper wire directly to the center of the earth... just doesn't get much better.  Now, it may eat up your copper in 5-10 years, but 20 feet of Romex is cheap. 

[Folsom]

Why do you want to do this?

[jea48]

For added lightning protection?

[Syrah]

To Folsom's question, my wife's answer is, "because he's insane".

My answer is more along the lines of this paper,

http://www.equitech.com/support/techgrnd.html

Better grounding (i.e. lower impedence path to ground) = lower system noise, at least in theory, I think.

I stewed about how to do this for 6 years, then it suddenly dawned on my that I have an unused salt water well 20 feet away from my exposed grounding rod, it seems like a reasonably cheap and easy experiment.

It's safe (I think) my earth ground will be undisturbed.

[jea48]

To Folsom's question, my wife's answer is, "because he's insane".

My answer is more along the lines of this paper,

http://www.equitech.com/support/techgrnd.html

Better grounding (i.e. lower impedence path to ground) = lower system noise, at least in theory, I think.

I stewed about how to do this for 6 years, then it suddenly dawned on my that I have an unused salt water well 20 feet away from my exposed grounding rod, it seems like a reasonably cheap and easy experiment.

It's safe (I think) my earth ground will be undisturbed.

The earth connection of an electrical service is for lightning protection and to limit high voltage from a fault on the high voltage side of the utility transformer to the secondary side of the utility transformer, from entering on the electrical wiring system inside the premise.

The service entrance neutral conductor is connected to earth. By connecting the service entrance neutral conductor to earth the AC power system becomes a "Grounded AC Power System".

The safety equipment grounding conductor's purpose is to provide a low resistive path for ground fault current to return to the source, the service entrance neutral conductor. The actual source is the utility transformer.

The earth does not possess some magical mystical power that sucks nastys from an audio system.

[Syrah]

Thanks jea48.

So is Equitech's notion that, by lowering the impedence of the earth ground (with a second grounding post, a chemical ground, etc), one could lower system noise, wrong?

[jea48]

Thanks jea48.

So is Equitech's notion that, by lowering the impedence of the earth ground (with a second grounding post, a chemical ground, etc), one could lower system noise, wrong?

YES. 

This thing does not have a mother earth connection.
https://www.youtube.com/watch?v=P30Jf6bN2EA

[Folsom]

Better ground can mean lower noise, but it's more about not sharing it with other things. The impedance only really matters until the panel for breakers. The ground noise earth rod that connects in breaker box doesn't matter too much.

This is NOT where I'd look to spend money. Consider some JPS in wall wire first. (could cost $1200 or so)

[jea48]

Thanks jea48.

So is Equitech's notion that, by lowering the impedence of the earth ground (with a second grounding post, a chemical ground, etc), one could lower system noise, wrong?

Quote from Link below:


 Grounding Myths

 From Henry W. Ott’s big new book "Electromagnetic Compatibility Engineering"

 3.1.7 Grounding Myths

 More myths exist relating to the field of grounding than any other area of electrical engineering. The more common of these are as follows:

 1. The earth is a low-impedance path for ground current. False, the impedance of the earth is orders of magnitude greater than the impedance of a copper conductor.

 2. The earth is an equipotential. False, this is clearly not true by the result of (1 above).

 3. The impedance of a conductor is determined by its resistance. False, what happened to the concept of inductive reactance?

4. To operate with low noise, a circuit or system must be connected to an earth ground. False, because airplanes, satellites, cars and battery powered laptop computers all operate fine without a ground connection. As a mater of fact, an earth ground is more likely to be the cause of noise problem. More electronic system noise problems are resolved by removing (or isolating) a circuit from earth ground than by connecting it to earth ground.

5. To reduce noise, an electronic system should be connected to a separate “quiet ground” by using a separate, isolated ground rod. False, in addition to being untrue, this approach is dangerous and violates the requirements of the NEC (electrical code/rules).

 6. An earth ground is unidirectional, with current only flowing into the ground. False, because current must flow in loops, any current that flows into the ground must also flow out of the ground somewhere else.

7. An isolated AC power receptacle is not grounded. False, the term “isolated” refers only to the method by which a receptacle is grounded, not if it is grounded.

 8. A system designer can name ground conductors by the type of the current that they should carry (i.e., signal, power, lightning, digital, analog, quiet, noisy, etc.), and the electrons will comply and only flow in the appropriately designated conductors. Obviously false."

 Henry W. Ott


Henry Ott,  "Electromagnetic Compatibility Engineering"
 

http://www.audiocircle.com/index.php?topic=109237.msg1139788#msg1139788

[Speedskater]

It matter not how many times the experts like Henry Ott, Ralph Morrison, Neil Muncy, Jim Brown, Bill Whitlock and the list goes on & on, write that the connection to Planet Earth has nothing to do with AC power quality on a day-to-day basis the mis-understanding continues. This electrical mis-understanding has been around for a century and it's not going to disappear.

[jea48]

Sorry, a follow up.  Does one test the quality of a ground by using a voltmeter and measuring the hot to ground voltage?  Is the higher that voltage the lower the ground resistance?   If so, the answer to my last question would be easy for me to test.

Thanks again!

You cannot test for Soil Resistivity using a volt meter.

It takes special testing equipment that is specifically designed to test the resistivity of the soil of the earth.

I do not want to leave you with the impression that the importance of a low soil resistance is not essential for good power quality of a Grounded AC Power System. A low earth ground resistance is very important in the event of a nearby lightning strike to the earth, or, a nearby lightning strike to overhead power lines. The lower the ground resistance the better. Simple ohms Law.... I believe the IEEE Emerald Book recommends for commercial and industrial Grounded AC Power Systems the earth ground resistance should be between 1 to 5 ohms max. Preferably 2 ohms or less.

For what it's worth I have never heard of a residential electrical contractor ever testing soil resistance for the grounding electrode system of a residential electrical service. I doubt you could find one that even own the test equipment.

 Probably everything you ever wanted to know about the subject you will find here.
http://support.fluke.com/find-sales/Download/Asset/2633834_6115_ENG_A_W.PDF

http://www.fluke.com/fluke/iden/products/categoryegt.htm


Here are a couple of other articles for you to read on the subject. (Note: I am not indorsing the GEM grounding enhancement system one way or the other.
http://www.erico.com/catalog/literature/E1081C-NAEN.pdf

Here is an older article that you may find interesting.
http://www.cpccorp.com/deep.htm

IF you have lost audio or video equipment, or appliances with microprocessors,  in your home due to a near by thunderstorm lightning strike/s then you might want to have the main grounding system of the electrical service checked.

(The technical name for the grounding system of the electrical service is called the Grounding Electrode System. The earth connection/s is called the Grounding Electrode. 

[FullRangeMan]

Sorry, a follow up.  Does one test the quality of a ground by using a voltmeter and measuring the hot to ground voltage?  Is the higher that voltage the lower the ground resistance?   If so, the answer to my last question would be easy for me to test.

Thanks again!

A suitable ground measure is the resistance, a good value is under 1 ohm, although after some months of winter the resistance it will no more be this good due oxidation.

[Speedskater]

To measure soil resistance requires a $2500 meter and maybe 1/2 hour's work.
The alternative? Just drive in a second ground rod.

To get under a 5 Ohm soil resistance might cost as much as an engineer's annual salary. And maintaining it adds to the cost.

[jea48]

To measure soil resistance requires a $2500 meter and maybe 1/2 hour's work.
The alternative? Just drive in a second ground rod.

To get under a 5 Ohm soil resistance might cost as much as an engineer's annual salary. And maintaining it adds to the cost.

Soil moisture maps for the USA

As you can see it depends on what part of the country you live in.

You might have one 5/8" x 8' ground rod where the soil resistance might measure on average through the year of 100 ohms. Driving a second rod might only drop the resistance to 50 ohms. Then what happens during the dry season?

You might find it is better to drive three coupled 5/8" x 10' ground rods 30' deep into the earth than drive three 5/8" x 10' ground rods individually into the earth. Like I said it depends on what part of the country and the type of soil involved. One size does not fit all.

There's a Firestone Tire Plant in my state, the Midwest, that has a single 50' deep (5 - 10' coupled ground rods), that has an electrode to earth resistance of 1 ohm.
It is checked 4 times a year. The 4 seasons.

[Speedskater]

A tire factory is one big building! Maybe a million square feet, or about 23 acres.

[FullRangeMan]

To measure soil resistance requires a $2500 meter and maybe 1/2 hour's work.
The alternative? Just drive in a second ground rod.

To get under a 5 Ohm soil resistance might cost as much as an engineer's annual salary. And maintaining it adds to the cost.

Sorry to ear it, also a 5 ohm resistance is useless to electronic equip, a good one is under 1 ohm. In a large industry where I work we measure the ground R w/a regular Fluke hand meter and the precision was good.

[jea48]

FullRangeMan  said:
In a large industry where I work we measure the ground R w/a regular Fluke hand meter and the precision was good.

Just to be clear, by "regular" you mean a clamp on meter like this Fluke.
http://www.fluke.com/fluke/iden/Earth-Ground/Fluke-1630.htm?PID=56021

>>>
A common power quality grounding issue that always seems to come up at Power Quality Seminars is the use of an isolated dedicated earth ground rod for a piece of sensitive electronic equipment.

The manufacture of the equipment says in the specs for the equipment it must have it's own dedicated earth ground connected to the supplied equipment ground terminal/lug. The specs also say the branch circuit equipment grounding conductor shall not be connected to the equipment. Then it says something like this, failure to follow the manufacture's equipment grounding instructions will void the equipment warrantee.
How many times have you seen that where you work? Talk about problems, down time, and lost production.

I see what the design EE of the equipment is trying to accomplish. He is trying to establish a low impedance ground plane around his sensitive equipment.
The correct way to wire the equipment, imo, would first be to spec the branch circuit conductors minimum size used based on a chart shown on the spec sheet for the distance, length, of the conductors from the electrical panelboard they will be fed from. As the distances increases, as shown on the cart, so does the size of the conductors. As for the equipment grounding conductor it shall be sized the same as the current carrying branch circuit conductors.

The branch circuit equipment grounding conductor shall connect to the metal frame/enclosure, of the equipment. Period!

If the EE designer of the equipment is still hell bent on the added earth connection, ground rod, then per NEC code he can add an auxiliary grounding electrode to supplement the branch circuit equipment grounding conductor that is connected, bonded, to his equipment.

And we wonder where an audio enthusiast gets the wild idea that a dedicated isolated ground rod will improve the sound of his audio system. Where would they get such an idea?