# Isolated Grounds



## Bob Badger (Apr 19, 2009)

gardiner said:


> I have been asked if there a code in the NEC or the CEC prohibiting the use of an Isolated Ground receptacle when there is no IG system present? The only thing I can think of (and this maybe because its close to quitting time on Friday) you would be using the receptalce in a manner it is not listed for. Any others?


There is an inspector in my area that says that, IMO they are wrong.


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## gardiner (Sep 25, 2007)

There is also an inspector in California and one in Ontario that says it too. I'm not 100% sure I agree or disagree on it myself as realy I am not a believer in IG's to start with. But I have been asked to find out just what codes in the two countries the practice of placing IG receptacles in Office furniture is breaking.


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## MDShunk (Jan 7, 2007)

gardiner said:


> I have been asked if there a code in the NEC or the CEC prohibiting the use of an Isolated Ground receptacle when there is no IG system present? The only thing I can think of (and this maybe because its close to quitting time on Friday) you would be using the receptalce in a manner it is not listed for. Any others?


It certainly would not be using the receptacle to its fullest potential, but it would be a stretch to say that you're misusing the receptacle. As long as both grounds are connected, what's the big deal.


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## raider1 (Jan 22, 2007)

MDShunk said:


> It certainly would not be using the receptacle to its fullest potential, but it would be a stretch to say that you're misusing the receptacle. As long as both grounds are connected, what's the big deal.


I agree.

Chris


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## ampman (Apr 2, 2009)

MDShunk said:


> It certainly would not be using the receptacle to its fullest potential, but it would be a stretch to say that you're misusing the receptacle. As long as both grounds are connected, what's the big deal.


 thats what i would think


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## Toronto Sparky (Apr 12, 2009)

An IG connected with a insulated ground right back to the panel is not much different than a true isolated ground..


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## gardiner (Sep 25, 2007)

Personally I don't see much reason for the isolated ground receptacle in the first place, but that is a whole other matter. The question was for codes, personal opinion means nothing. I have had inspectors in California and in Ontario refuse to pass an installation where they found an IG receptacle in some furniture. 

Now I don't get to talk to the inspector or even finding out what code reference they are using the word "fail" comes down marketing pays to change whatever the inspector says right away. 

So if there is a code I want to know it, I'm willing to learn.


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## manchestersparky (Mar 25, 2007)

I would be willing to bet the inspectors are looking at 406.2(D)(1) and 250.146(D).

The OP did not clarify what he meant by " No IG System Present".
Is he is referring to using an IG receptacle on a standard circuit that does not contain the insulated equipment grounding conductor that is attached to the grounding terminal on the receptacle ONLY plus have another grounding means for the box ? 
According to article 250.146 (D) the insulated equipment grounding conductor ,for an IG , is to be ran to the grounding terminal of the applicable derived system ( transformer) or service. This does not mean a subpanel off another panel.


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## Bob Badger (Apr 19, 2009)

manchestersparky said:


> I would be willing to bet the inspectors are looking at 406.2(D)(1) and 250.146(D).


250.146(D) is full of 'may' and 'permitted' not so many 'shall'.


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## manchestersparky (Mar 25, 2007)

Bob Badger said:


> 250.146(D) is full of 'may' and 'permitted' not so many 'shall'.


In reality section 250.146(D) Has the words "shall" in it 4 times, "permitted" 2 times and "may" 0 times 
The first sentence of the section says that it's allowed ( shall be permitted) to use a receptacle that has the grounding terminal insulated from the yoke.
The second sentence tells us that the insulated grounding terminal must (Shall) be connected to an insulated conductor. 
The third sentence says that This insulated conductor is allowed ( shall be permitted)to be run with the circuit conductors AND to pass through panelboards WITHOUT terminating in them as allowed ( permitted) 408.40. The insulated grounding conductor is allowed to pass through numerous panelboards without attaching to them in route to the applicable derived system or servcie.
Sentence four tells is that that insulated conductor is allowed ( shall be permitted) to pass through various wireways, boxes, or other enclosures without connecting to them, in order to reach the applicable derived system or service.
Basically I read it as saying that an IG is to be run back to the service or derived system. It is allowed to be run with the circuit conductors and if they do not originate at the service (or at the derived system) then the IG is allowed to be run through various other boxes, panelboards, wireways, in order to reach the service. When passing through these boxes, wireways, panels, it is not to be terminated to any of them.


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## gardiner (Sep 25, 2007)

manchestersparky said:


> I would be willing to bet the inspectors are looking at 406.2(D)(1) and 250.146(D).
> 
> The OP did not clarify what he meant by " No IG System Present".
> Is he is referring to using an IG receptacle on a standard circuit that does not contain the insulated equipment grounding conductor that is attached to the grounding terminal on the receptacle ONLY plus have another grounding means for the box ?
> According to article 250.146 (D) the insulated equipment grounding conductor ,for an IG , is to be ran to the grounding terminal of the applicable derived system ( transformer) or service. This does not mean a subpanel off another panel.


Your right I did not clarify this properly IG receptacle connected to an insulated ground the tied to a bare ground to travel back to the panel.

Thanks for the responses this gives me a little work with now any Canadian Electricians out there no of anything in the CEC?


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