# Isolated grounding?



## Axidias (Dec 3, 2009)

I've heard some talk about computers messing up lately and how an isolated ground will get rid of the noise and make everything run more smoothly. It sounds like something I should do but I'm not sure. We have a wireless antenna on the roof for internet and a router and the computer are all on one power strip.. Would I need to put the computer, router, internet antenna on different isolated outlets or would the power strip with everything on it, plugged into an isolated outlet be just as good? I guess I also wonder about how it works because the neutral of the outlet still goes to the main panel and still ties into the other neutrals and bonds to the main ground. Maybe I am thinking about it all wrong nline2long:


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## Grimlock (Aug 4, 2009)

IGs are used to lessen Harmonics that may be introduced from various sources such as fluorescent lighting. IGs require an IG receptacle and should only be used by the equipment you wish to be free of the distortions caused by the harmonics. The ground has to be terminated at the location of the source winding and requires a separate ground bus.


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## Axidias (Dec 3, 2009)

Grimlock said:


> The ground has to be terminated at the location of the source winding and requires a separate ground bus.


Can you clear that up a bit? From what I can figure out, you mean it goes from the grounding electrode rod to the outlet and nowhere else. But that separate ground bus bit is throwing me off..


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## Speedskater (Oct 2, 2009)

The following papers are about audio, but computers have the same noise problems.

The Bill Whitlock of Jensen Transformers Seminar paper
http://www.jensen-transformers.com/an/generic seminar.pdf

The Jim Brown of Audio Systems Group white paper
"Power and Grounding for Audio and Audio/Video Systems"
http://www.audiosystemsgroup.com/SurgeXPowerGround.pdf

"The TRUTH" from ExactPower of Middle Atlantic Products
http://www.exactpower.com/elite/wpapers.aspx

or a different version of the same paper

"Power White Paper" from Middle Atlantic.com
http://www.middleatlantic.com/power.htm


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## Grimlock (Aug 4, 2009)

Well, all of the IG's that I have installed have been on commercial projects and I have terminated the IG at the transformer. The separate bus is just a ground bar placed in the panel with insulated mounts to keep it isolated from the "Dirty" ground.

The term “source winding” refers to the origin of a separately derived system.

I’m not sure what the best termination point would be for a residential IG, anyone have any ideas?
EDIT: BTW I don't think terminating at the ground rod would be a good idea.


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## Toronto Sparky (Apr 12, 2009)

Any non-linear load on the IG circuit defeats it's purpose.


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## gardiner (Sep 25, 2007)

There are many schools of thought on whether an IG does anything beneficial or not. For the most part you will not be able to get a true IG circuit going in a residential situation, and if you truly wish to reduce potential problems there are a few simple steps you might want to try. Separate the computer CPU from all other devices on a separate circuit, this will reduce some potential conflicts, it might also be wise to place a surge protection device on this circuit as in residential settings that is more likely to be the problem then noise would be. If possible and not already done upgrade your router and wireless card in your computer to the highest level available.


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## Grimlock (Aug 4, 2009)

Try one of these first:

They claim to be "Noise filtering" which may solve your problem.

http://www.amazon.com/Leviton-Suppr...al-Specification/dp/B0006I33Y6/ref=pd_cp_hi_0

$27.61 Seems to be a good price too.


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## BuzzKill (Oct 27, 2008)

gardiner said:


> There are many schools of thought on whether an IG does anything beneficial or not. For the most part you will not be able to get a true IG circuit going in a residential situation, and if you truly wish to reduce potential problems there are a few simple steps you might want to try. Separate the computer CPU from all other devices on a separate circuit, this will reduce some potential conflicts, it might also be wise to place a surge protection device on this circuit as in residential settings that is more likely to be the problem then noise would be. If possible and not already done upgrade your router and wireless card in your computer to the highest level available.


 yeah totally seems impossible for resi work as you would have to run your own ground to the xfmr.


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## Mr. Sparkle (Jan 27, 2009)

If your using NM and plastic boxes in a residential setting and your branch circuit goes to the Main Panel, not a sub panel, that is an IG circuit.


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## BuzzKill (Oct 27, 2008)

Mr. Sparkle said:


> If your using NM and plastic boxes in a residential setting and your branch circuit goes to the Main Panel, not a sub panel, that is an IG circuit.


 supposedly..where's the difference? All of your grounds are tied together.


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## Old Spark (Nov 18, 2008)

The primary ground is at the Main Switch Board or Panel. If you have sub panels, and your computer circuit is from the sub panel, then you will need a second ground wire from the main panel (MSB) to the sub panel to ground an Isolated Ground Bar. This bar is isolated from the sub panel can and the other grounding. This is common in commercial, but not residential. It could be difficult to get the second ground wire to a sub panel if not installed during construction of the project. I think some of the suggestions made by others to you are good suggestions regarding surge protection strips and dedicated circuit.


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## drsparky (Nov 13, 2008)

What ever happened to electrical professionals only?


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## BuzzKill (Oct 27, 2008)

my thinking is to be properly isolated, the (IG) ground needs to return to it's host, it's "source winding": the xfmr, as stated by Grim; in resi, a circuit simply having it's own isolated ground wire returning to the panel doesn't quite do it for me, although I may be wrong. I have worked with true IG's only in commercial also, where the IG ground is isolated from the panel and run to the source, the xfmr.


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## TOOL_5150 (Aug 27, 2007)

Axidias said:


> I've heard some talk about computers messing up lately and how an isolated ground will get rid of the noise and make everything run more smoothly. It sounds like something I should do but I'm not sure. We have a wireless antenna on the roof for internet and a router and the computer are all on one power strip.. Would I need to put the computer, router, internet antenna on different isolated outlets or would the power strip with everything on it, plugged into an isolated outlet be just as good? I guess I also wonder about how it works because the neutral of the outlet still goes to the main panel and still ties into the other neutrals and bonds to the main ground. Maybe I am thinking about it all wrong nline2long:


Computers messing up have nothing to do with having or not having an IG... They couldnt care less. You probably have a virus or spyware. Stop looking at ****.

~Matt


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## BuzzKill (Oct 27, 2008)

TOOL_5150 said:


> Computers messing up have nothing to do with having or not having an IG... They couldnt care less. You probably have a virus or spyware. Stop looking at ****.
> 
> ~Matt


 Yeah it's God who is f*cking with your computer. :laughing:


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## eddy current (Feb 28, 2009)

I think IG's, cause more problems than solve any. Most buildings don't even have an isolated ground, they all go to the same ground bus and the buildings that do have isolated ground bars, in my experience, cause problems. I measured 65 volts from the regular ground bar to the isolated ground bar one time . For computers you should run a separate neutral to lower the harmonics. Meaning each circuit has it's own neutral instead of sharing one.

All the new projects we do run separate neutrals for every circuit, not isolated grounds. And all the panels have the neutral twice the size of the mains. For instance, a 100amp panel would have three #3's for phases A,B,C and two #3's for the neutral. You have to run bigger conduit but this is spec'd for the job.
We just did a big job for IBM and last year we did the new Adobe, both computer based companies. Not a single IG plug on either of those jobs.


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## Mr. Sparkle (Jan 27, 2009)

BuzzKill said:


> supposedly..where's the difference? All of your grounds are tied together.


I hear ya, I'm just saying that is as good as your gonna get in that situation. 

And I heard too much animal **** will cause the problem the OP is having.

And I agree with what Eddy said and find it interesting that there was not a single IG circuit in those projects, guess the money is in the neutral.


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## eddy current (Feb 28, 2009)

IG is old technology. I've removed more IG receptacles than installed them. You wouldn't believe the size of the box we have at the shop full of them.


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## Axidias (Dec 3, 2009)

What is this, a damn pissing match? I just heard people talking about them around here, I never said my computer was messing up. I never messed with an IG or learned about them. Thanks to the ones who actually taught me something! :thumbsup:


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## RIVETER (Sep 26, 2009)

*Isolated Ground*



Axidias said:


> What is this, a damn pissing match? I just heard people talking about them around here, I never said my computer was messing up. I never messed with an IG or learned about them. Thanks to the ones who actually taught me something! :thumbsup:


A ground, is a ground, is a ground. It is nothing else. It is a reference to earth. An EARTH ground ...or not...will not mess up a computer...unless you have other circumstances.


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## Grimlock (Aug 4, 2009)

RIVETER said:


> A ground, is a ground, is a ground. It is nothing else. It is a reference to earth. An EARTH ground ...or not...will not mess up a computer...unless you have other circumstances.


Depends on what you qualify as "messing up". We had a job where moniters where being distorted by close proximity to the metal surfaces of the cubicles they where stationed at. By adding an IG the problem went away. I was not directly involved in the project and there may have been more involved than was explained to me but my understanding is that an IG was the solution.


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## Old Spark (Nov 18, 2008)

I'm curious, did you try to figure out why there was 65 volts between regular and iso ground. It sounds like a high resistant short somewhere. I find it interesting about doubling the size of the neutral. A few years ago we stopped down sizing the neutral and running it full size, I'll bet doubling the size will be a smart thing to do. I'll have to talk with some engineers out here and see if they will start designing it in. All our jobs here still require isolated grounds in commercial work. It sounds like that needs to change. I like learning new stuff! I may be old, but you can't stop learning or you become stale.
David


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## Old Spark (Nov 18, 2008)

:001_huh:


David Channell said:


> I'm curious, did you try to figure out why there was 65 volts between regular and iso ground. It sounds like a high resistant short somewhere. I find it interesting about doubling the size of the neutral. A few years ago we stopped down sizing the neutral and running it full size, I'll bet doubling the size will be a smart thing to do. I'll have to talk with some engineers out here and see if they will start designing it in. All our jobs here still require isolated grounds in commercial work. It sounds like that needs to change. I like learning new stuff! I may be old, but you can't stop learning or you become stale.
> David


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## gardiner (Sep 25, 2007)

Grimlock said:


> Depends on what you qualify as "messing up". We had a job where moniters where being distorted by close proximity to the metal surfaces of the cubicles they where stationed at. By adding an IG the problem went away. I was not directly involved in the project and there may have been more involved than was explained to me but my understanding is that an IG was the solution.


This is a situation I have heard of many times in the past. Typically I have found one of two things had occurred. One was the furniture was designed to use the shared neutral system where the neutral was not oversized to handle the multiple loads. Or the furniture used the independent neutral system but was being fed by a shared neutral from the panel. In both cases the installation of IG receptacles in the furniture will help reduce the problem (notice reduce not solve).


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## Toronto Sparky (Apr 12, 2009)

I once went to a call at a bank where the computers that were plugged into the IGs were messing up alot.. I stuck one of those three lamp tester cubes in the outlet and all three lights came on.. 
Turns out that the main IG bus feed was run into a old electrical room and attached to the switchgear.. The said switch gear had been removed the week before ..
So all the IG plugs had the grounds all tied together but floating..


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## BuzzKill (Oct 27, 2008)

David Channell said:


> I'm curious, did you try to figure out why there was 65 volts between regular and iso ground. It sounds like a high resistant short somewhere. I find it interesting about doubling the size of the neutral. A few years ago we stopped down sizing the neutral and running it full size, I'll bet doubling the size will be a smart thing to do. I'll have to talk with some engineers out here and see if they will start designing it in. All our jobs here still require isolated grounds in commercial work. It sounds like that needs to change. I like learning new stuff! I may be old, but you can't stop learning or you become stale.
> David


 Yes, definately up size the neutral nowadays with all the increased harmonics in circuits.


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## Old Spark (Nov 18, 2008)

You've heard it said misery loves company. At least all the computers could share their problems. No real electrician would think that tieing all the grounds together, but not land them on a good ground would do the job. I just visited a gas station where all the conduits were run on top of the ground just before concrete. You know what happened when someone sawcut for a new trench. This was done over 15 years ago, so it did work long enough for the electrician and the inspector to be long gone.


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## eddy current (Feb 28, 2009)

David Channell said:


> I'm curious, did you try to figure out why there was 65 volts between regular and iso ground.David


I found the problem on a service call. Guy was complaining about noise coming from his radio in the office he was recently moved to. When I plugged the radio in a regular socket, the noise went away. In the panel is where I was reading the voltage from ground to isolated ground. I showed this to the property management company that looks after the building. They said they would look into it, I never heard back.
There was only two other IG circuits in the panel and both were not being used. I turned the power off to all three IG circuits and still had voltage from ground to ground.


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## drsparky (Nov 13, 2008)

All grounds may be created equal but all ground conductors are not.
Take 300 feet of #10 and ground one end, the other end will be above ground because of the resistance in the wire. Now put an air conditioner on the end of the wire, as the motor starts and stops it will induce current spikes into the ground conductor. The grounding conductor will bleed off the voltage but it must flow to ground first.
Now run another 300 feet of #10 and ground one end. The far end has a computer, it will not produce any spikes so its ground conductor will be "cleaner".
A more accurate term would be an _isolated ground conductor_. The goal of an isolated ground conductor is to separate noisy equipment from precision equipment. If we put a ground rod next to each piece of equipment it would accomplish the same thing but it is easier and cheaper to provide two paths to ground, one clean (isolated) and one dirty (normal).:thumbsup:


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## RIVETER (Sep 26, 2009)

*Isolated ground*



drsparky said:


> All grounds may be created equal but all ground conductors are not.
> Take 300 feet of #10 and ground one end, the other end will be above ground because of the resistance in the wire. Now put an air conditioner on the end of the wire, as the motor starts and stops it will induce current spikes into the ground conductor. The grounding conductor will bleed off the voltage but it must flow to ground first.
> Now run another 300 feet of #10 and ground one end. The far end has a computer, it will not produce any spikes so its ground conductor will be "cleaner".
> A more accurate term would be an _isolated ground conductor_. The goal of an isolated ground conductor is to separate noisy equipment from precision equipment. If we put a ground rod next to each piece of equipment it would accomplish the same thing but it is easier and cheaper to provide two paths to ground, one clean (isolated) and one dirty (normal).:thumbsup:


I am trying to follow this and some ...I agree with. I'm not sure why you are only grounding one end of the computer circuit. The GROUND is in reference to earth via an ELECTRODE in close contact with the earth. It should be grounded at the service and a continuous bond maintained throughout. In most cases I would think that the majority of problems would be in the CROSS-TALK between neutrals...but then I am not a computer person.


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