Do People Say "Insulated Ground" As Opposed To "Isolated Ground"

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shamsdebout

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Macon,GA
I saw something from a IEEE standard that discouraged the use of "isolated ground" or "isolated grounding receptacle", with the preferred terminology being "insulated ground" and insulated grounding receptacle". Now I know the NEC uses "isolated" and in some rare instances "insulated" to refer to grounding conductors. Have you ever heard anyone in industry use the IEEE preferred terminology? Does this preferred terminology really convey the same idea? When I think of an insulated grounding conductor, the thought it convey is to cover the bare conductor with insulation.
 

techelec

Member
Insulated ground and isolated ground are two different items. Insulated is a ground wire that has a covering of a material that is NEC approved and isolated ground deals with a separate grounding system than that of the equipment grounding system.
 

Hameedulla-Ekhlas

Senior Member
Location
AFG
Insulated grounding is a cable which contains a cover. I have seen it as a green cable cover cable and also it is used in grounding system. Suppose if we have four ground rods as a square these rods are connected with an other by bare cable. The cable between panel board and rods which connected by clamps is called insulated cable and it is a cover cable.

Isolated ground is a separate ground system. If you connect all equipment system to one ground system and one large equipment to other separate ground. This is called a isolated ground system.
 

charlie b

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Location
Lockport, IL
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Semi-Retired Electrical Engineer
Insulated ground and isolated ground are two different items.
Insulated grounding is a cable which contains a cover.
You two are not reading the question carefully. The OP said essentially the same thing. But it's not as simple as that.


For starters, if you really intend to run an "isolated ground," then the wire you use has to be "insulated," or it will not be able to do its intended job. So if and IEEE standard chooses to use the phrase "insulated ground," to describe the situation in which two separate EGCs run from a receptacle to the panel (one connected to the receptacle's ground pin, the other to the receptacle's yoke), then that is their prerogative. There is some sense in the use of that phrase. But not enough sense for my tastes. I think it leads to confusion.

To answer your specific question, I have not encountered the use of ?isolated ground? in this context. What is the IEEE source in which you saw it used?
 

shamsdebout

Senior Member
Location
Macon,GA
You two are not reading the question carefully. The OP said essentially the same thing. But it's not as simple as that.

For starters, if you really intend to run an "isolated ground," then the wire you use has to be "insulated," or it will not be able to do its intended job. So if and IEEE standard chooses to use the phrase "insulated ground," to describe the situation in which two separate EGCs run from a receptacle to the panel (one connected to the receptacle's ground pin, the other to the receptacle's yoke), then that is their prerogative. There is some sense in the use of that phrase. But not enough sense for my tastes. I think it leads to confusion.

To answer your specific question, I have not encountered the use of ?isolated ground? in this context. What is the IEEE source in which you saw it used?

Thanks Charlie, it is from the IEEE 1100 Standard
Here is an exerpt from 4.8.5.1 Single-point grounding:
There has been a lot confusion about ?isolated grounds? and single-point grounding. The purpose of SPG is
to minimize interference problems caused by circulating current in ground loops. This is accomplished by using insulated EGC to control where the ground connections are made to the NEC-required grounding system. The insulated EGC originates at the ground pin of a special receptacle that has the ground pin isolated from the mounting yoke, hence the original name isolated grounding receptacle. It can also originate on an equipment grounding terminal block in the electronic equipment. The insulated EGC
terminates at the point where neutral and ground are bonded at the power source or a separately derived source. To some people, the term isolated ground implied that this receptacle was not connected to the building
grounding system, and some manufacturer?s literature specified a separate ground for their equipment. To eliminate this confusion, this standard discourages the use of isolated ground and isolated grounding
receptacle. The preferred terminology is insulated ground (IG) and insulated grounding receptacle (IGR).
 

steve66

Senior Member
Location
Illinois
Occupation
Engineer
I also prefer the term "insulated ground". To me, an isolated ground receptacle is one that is fed through an isolating transformer, like the ones that serve operating rooms. They are truely isolated. (I once watched a service tech lick his fingers, and then grab the line and the ground with opposite hands.)

Steve
 

shamsdebout

Senior Member
Location
Macon,GA
I also prefer the term "insulated ground". To me, an isolated ground receptacle is one that is fed through an isolating transformer, like the ones that serve operating rooms. They are truely isolated. (I once watched a service tech lick his fingers, and then grab the line and the ground with opposite hands.)

Steve

What went through your head as you watched him do that?
 

steve66

Senior Member
Location
Illinois
Occupation
Engineer
What went through your head as you watched him do that?


I was familiar with the isolated power supplies, so I knew it wouldn't shock him.

I was mostly just hoping someone didn't see him do that, and try the same thing with both line terminals!!
 

dereckbc

Moderator
Staff member
Location
Plano, TX
Well I know the guy who co-authored the IEEE Emerald Book. I sleep with him every night, and have to look at his ugly face every time I look in the mirror. :grin:

IG or insulated ground is the term used to identify an Isolated Single Point Ground Plane. A very special grounding topology used in communication equipment like Telephone Switches.

IGR or Isolated receptacle ground is what most electricians are familiar with in the NEC.
 
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