Isolated Ground causes ground hum.


Hi Experienced Goner.
I am adding the isolated ground into my music system and when I connected the ground wire into my existing system and it hums badly.
Did I do st wrong?
 Thanks 
Calvin
dangcaonguyen
I only connected it to the ground post on my Shindo Aurieges preamp.
Post removed 
What do you mean "isolated ground?"


I hammered three copper rods under the ground then linked them together with a solid 4 awg copper wire and through the exterior wall into my music room.
When i touched that wire to the ground post on the preamp, hum occurred. Thanks 
@dangcaonguyen

By law, you MUST bond them to the house ground.  You can't just create a new ground field, and run a copper wire to your outlets and call it ground.

Best,
E
@erik_squires 
Thank you,
and that was what I did. My outlet is still keeping as normal, 1 ot, 1 neutral, and 1 ground. I only added the extra isolated ground bond the the chassis of the preamp. Is it the same as I bond it to the common ground of the Edison?
Please let me know if what I an thinking is right?

I figured out where the problem is. It is on the Conrad Johnson amplifier. When I plugged it into the outlet out of my dedicated line network, or when I used the cheat plug, the hum was gone.
Now, anyone has any idea of how to fix it will be much appreciated.
 Thanks 
I'm not an electrician, but I have two ground rods installed to my house.
  There is an earth ground attached to your service panel (circuit box) which is the ground for all circuits in your house. 
  If you have a dedicated AC line, it is also grounded to your house. You may attach a ground rod to this line which has an isolated hot and neutral to your system. 

There can only be one ground for the entire house and your components must share this ground.

I stand under correction but i Have found that if all are common ground with good rca cables that should sort it unless one of your devices has a switch mode power supply, that can cause chaos!
colin, assuming there is a common ground, in theory there should be no grounding issues using RCA cables. But not all components use the same grounding scheme, so there may be a difference in ground potential which cause ground faults. Also some RCA cables use a ground connection, some don’t. In these situations there may be hum or noise introduced.

With a SMPS the issue is noise. These power supplies can bleed noise or interference back down their power cord into the mains thus contaminating the entire system.
Some modern components are using high quality internal SMPS’s. It’s the wall-warts that add noise and are not as effective as a linear power supply.

Hi Experienced Goner.
I am adding the isolated ground into my music system and when I connected the ground wire into my existing system and it hums badly.
Did I do st wrong?
Thanks
Calvin
dangcaonguyen12-19-2018 7:34pm

dangcaonguyen OP113 posts12-19-2018 9:43pm

I hammered three copper rods under the ground then linked them together with a solid 4 awg copper wire and through the exterior wall into my music room.


dangcaonguyen OP113 posts12-19-2018 9:45pm

When i touched that wire to the ground post on the preamp, hum occurred. Thanks

You got the hum because there is a difference of potential, voltage, between the new isolated earth connection and your homes main electrical service earth connection.

An isolated earth connection is great for lightning frying your audio equipment. A high voltage lightning transient could enter on your new earth ground connection, travel through your audio equipment, travel out through the equipment grounding conductor at the wall outlet through the equipment grounding conductor of the branch circuit wiring, back to the main electrical panel main service neutral/equipment ground, and then back to earth through the earth ground connection for the electrical service.... Oh and in less than a blink of an eye the event takes place. The lightning high voltage transient may jump across to other branch circuit wiring and fry other equipment and appliances on it way back to mother earth.

An isolated earth connection does nothing for improving the sound of an audio system. Mother earth does no possess some mystical magical power that sucks nasties from an audio system. If anything in your case it adds noise.



dangcaonguyen OP113 posts12-19-2018 11:29pm

I figured out where the problem is. It is on the Conrad Johnson amplifier. When I plugged it into the outlet out of my dedicated line network, or when I used the cheat plug, the hum was gone.
Now, anyone has any idea of how to fix it will be much appreciated.
Thanks

Yeah, ditch the isolated ground electrode. ( New ground rods).If you think you need a lower resistance earth connection then connect your 3 new ground rods to the main earth grounding system of the electrical service. A minimum #6awg copper wire is required by code. Use Approved grounding clamps.

Here is some great reading material on grounding.
https://centralindianaaes.files.wordpress.com/2012/09/indy-aes-2012-seminar-w-notes-v1-0.pdf

Jim
@jea48 
Thank you for the paper, it helps a lot. 
What do you think about the use of Isolated Ground Receptacle in this case.
Thanks
What do you think about the use of Isolated Ground Receptacle in this case.
Thanks
First, what is an IG, (Isolated Ground) receptacle?
A receptacle where the female equipment ground contact is isolated electrically from the receptacle supporting back strap.

What is the intended use of an IG receptacle?
To provide a connection to the equipment ground contact of the receptacle using an insulated equipment grounding conductor run with the branch circuit wiring back the the electrical panel the branch circuit is fed from. The insulated equipment grounding conductor connects to the ground bar in the electrical panel. (Exception: NEC allows the insulated equipment grounding conductor to pass through a sub panel and connect to the ground bar in the Main electrical service panel)

IG receptacles are used in commercial and industrial occupancies where metallic electrical conduit is used for branch circuit wiring. The idea is noise maybe traveling on the metallic conduit. The IG receptacle equipment ground contact is isolated from the metallic conduit. IG receptacles were popular in the 1970s, 1980s, maybe 1990s, but not so much in the last several years.

Two equipment grounding conductors are required when using an IG receptacle. One (insulated) for the ground terminal/ground contact of the receptacle and the other to ground the receptacle supporting back strap. Metallic conduit is an approved equipment grounding conductor per NEC Code. Where the conduit is not to be used as the equipment grounding conductor a separated equipment grounding conductor is pulled in the conduit and bonded, connected to the metal receptacle rough in box.

IG receptacle Connected to a Romex branch circuit?
Serves no purpose. If the Romex is terminated in a metal box Code says the equipment grounding conductor in the Romex must be bonded, connect, to the box. A grounding pigtail is also connected to the Romex equipment grounding conductor and connected to the IG receptacle equipment grounding terminal. If a plastic box is used NEC allows an IG receptacle but requires a non conductive receptacle cover plate shall be used.
Jim
OK, so yes, you just created your own ground loop. :)

What you can do: 

Add more ground rods.
Bond them to house ground rod farmRun 1 ground wire directly to the ground rods, and use that for your outlets.

Then run phono grounds like normal, from device to device.
@ erik_squires
Add more ground rods.
Bond them to house ground rod farm. Run 1 ground wire directly to the ground rods, and use that for your outlets.

Not sure what you are recommending to the OP. Would you please expand.
NEC requires the equipment grounding conductor to be installed in the same raceway or part of the same cable assembly, (Example Romex).
NEC does allow an Auxiliary Grounding Electrode. NEC 250.54...  I wouldn’t recommend it. It supplies a path for lightning to enter the OPs home.

2008 NEC—250.54

Auxiliary Grounding Electrodes.

One or more grounding electrodes shall be permitted to be connected to the equipment grounding conductors specified in 250.118 and shall not be required to comply with the electrode bonding requirements of 250.50 or 250.53(C) or the resistance requirements of 250.56, but the earth shall not be used as an effective ground-fault current path as specified in 250.4(A)(5) and 250.4(B)(4).

https://www.ecmag.com/section/codes-standards/significant-changes-nec-2008-0
The Aux grounding Electrode Shall connect to the branch circuit equipment grounding conductor. Lightning loves an Aux grounding electrode.

.

https://www.youtube.com/watch?v=WlnFNTay-9Q
Jim

I would think long and hard about adding the ground rods.  If you did get hit by lightning or gave an electrical fire, it’s a sure bet your homeowners insurance may be quite reluctant to cover the loss.  To be sure, I would have a local certified and licensed electrician check out your wiring set up. 
@JEA48

As far as I know, the NEC does not specificity a maximum number of ground rods, so long as they are all bonded together. That's what I am referring to.

Best,
E
@ erik_squires

Thank you for the clarification.

Yes you are correct there is no limit to the number of earth ground rods as long as they are all tied together. They then become one electrode. One ground wire is extended and then connected to the service entrance neutral conductor in the main electrical service equipment/panel.
Jim
Check out the Ground Master box from Puritan Audio. It will cost you $165 you will just need to connect your ground wire to it. You can read Paul Rikby’s review.
Please don’t add any ground rods yourself. 
Have a licensed sparky do it. I’m sure it won’t improve your current sq situation. 
Don't understand why you would want to add ground.
If you live in the USA your household 120V power has a ground wire for protection from isolation failures as to make the breaker pop.
The neutral is connected the center-tap on the 240V transformer on the pole outside your house. 
The neutral carreies only current when a load is connected and will have a voltage potential to the ground in the outlet equal to the resistance dropout from the load current. 
This protection scheme can sometime cause trouble, and is one of the reasons balanced audio is used to explicitly avoid ground loops.
Leakage currents in high voltage transformers can also be a problem, and may leak into other windings on the same transformer.
You could try an ultraisolation transformer to isolate your neutral from the house neutral/ground.
I have 2000va Topaz transformer for this.
Adding ground rods nilly willy is not a good idea.
The problem is not the CJ amplifier, it's the extra ground. The earth is a poor conductor and that results in steady state potential in the ground -- which is the source of your humming.

An extra ground is not a good idea. Lightning surges isn't the only problem -- transient spikes occur all the time, such as utilities switching  capacitor banks and on-site generating facilities switching loads from utility to generators, any of which can produce transients to fry your electronics connected on a grounding system with a potential across it.
Hi everyone,
The humming problem is solved. I want to report back on what I have done to it.
1) Connected the ground to the conduit metal outlet box.
2) Connected the Isolated Ground (from my ground post) to the ground pin of the IGR receptacle.
3) The hot and neutral are connected as normal.
I changed the 4awg solid copper bare wire to 6awg insulated strained wire to match with the NEC code.
Result: The sound has improved by not a small margin. In all directions, soundstage, bass, image... you name it.
The only concern I have for now is how to protect my system from the lightning as Jim mentioned.
$100.00 well spent.
Calvin

2) Connected the Isolated Ground (from my ground post) to the ground pin of the IGR receptacle.
Dangerous and against Code. In the event of a hot to chassis ground fault event, of a piece of audio equipment plugged into the IG receptacle, there is not a low resistive path for the ground fault current to travel back to the source, the electrical panel. The breaker that feeds the branch circuit will never trip open. In fact there is a good chance the chassis of the piece of equipment would be Hot, energized, with respect to any other grounded item that is connected to the main electrical service equipment ground. An electrical shock, or worse, electrocution hazard.

I also suggest you reread erik-squires and gs5556 posts.

Again.... The earth does not posses some mystical magical power that sucks nasties from audio equipment. If anything it can add noise. You won’t find any well respected EE that will tell you otherwise.

3)
I changed the 4awg solid copper bare wire to 6awg insulated strained wire to match with the NEC code.
#6 is bare minimum. You can use larger.

Did you click on the Link with the video I supplied in an earlier post?
https://www.youtube.com/watch?v=WlnFNTay-9Q

That guy talking helps write NEC Code.

Thank you everyone,
I will remove the isolated ground system and put my music system back as before.
One last question:
Do I have to remove all the ground rods I already planted is in the ground? Is there any issue if I keep them there? Its kind of hard to remove those rods now.
Thank you all for your help.
Calvin
dangcaonguyen
Do I have to remove all the ground rods I already planted is in the ground?
No, you could bond them together with your other existing ground rods.
Do I have to remove all the ground rods I already planted is in the ground? Is there any issue if I keep them there? Its kind of hard to remove those rods now.
No problem with leaving them there. I would remove the ground wire from the rods from the inside of the house. Cut it off outside the house or bury it in the ground outside the house.
One major thing I've learned over the years of reading the Audiogon Forums is you never can go wrong following the advice of jea48, gs556 and several others that I have not mentioned. Thank you to all those prefessionals...
"I only connected it to the ground post on my Shindo Aurieges preamp. "

Isn't the purpose of that grounding lug as a place to ground your turntable or phono preamp?  I assume the chassis of the preamp is already grounded.
lak,

Thank you for the kind words.
Jim
I put my system back to normal. Thank you for talking me out of the dangerous isolated ground gentlemen.
Calvin