Isolated Ground w/ GFI receptacle

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boater bill

boater bill

Senior Member
Location
Cape Coral, Fl.
Has anyone ever seen, spec'd or installed a GFI receptacle on an isolated ground circuit?
It is for a computer circuit and there is a sink in the vicinity that requires it to be GFI.
It appears the GFI receptacle should operate correctly but want to make sure.
Of course the sink and computer have some compatability issues also.:wink:
 
I frequently see references to "isolated" ground circuits. I assume you mean there is a dedicated insulated ground wire going back to the main panel.

Isn't the correct term for this an "insulated" ground?

I'm not trying to split hairs, but when someone says "isolated" ground I think of the isolation transformers that are normally used in operating rooms.

If it is the insulated ground wire (and not the isolated transformer) circuit, I don't see any problem with a using a GFCI receptacle.

Steve
 
boater bill said:
It is for a computer circuit and there is a sink in the vicinity that requires it to be GFI.
Click to expand...
Bill, your in Fl on the 05. If this is not a dwelling, no GFCI required unless speced.
 
benaround said:
Do they make IG GFCI recpts. ? if not both EGC will connect at the box via

the yoke, right?
Click to expand...
If it is a metal box, yes... plastic, no. :roll:

...and I've never seen an ig-gfci receptacle.
 
steve66 said:
I frequently see references to "isolated" ground circuits. I assume you mean there is a dedicated insulated ground wire going back to the main panel.

Isn't the correct term for this an "insulated" ground?

I'm not trying to split hairs, but when someone says "isolated" ground I think of the isolation transformers that are normally used in operating rooms.

If it is the insulated ground wire (and not the isolated transformer) circuit, I don't see any problem with a using a GFCI receptacle.

Steve
Click to expand...

IG in my expierence = isolated ground.

http://ecmweb.com/mag/electric_demystifying_isolated_grounding/
 
I've never seen one specified that way, but I agree, you will need an IG receptacle with an upstream GFCI branch breaker, since I don't think they make an IG & GFCI receptacle.
 
Just got off the phone with the supply house - ordered three IG/GFCI receptacles for a doctors office we're finishing up. Will be in on Tuesday - Guess they do make them.
 
steve66 said:
I frequently see references to "isolated" ground circuits. I assume you mean there is a dedicated insulated ground wire going back to the main panel.

Isn't the correct term for this an "insulated" ground?

I'm not trying to split hairs, but when someone says "isolated" ground I think of the isolation transformers that are normally used in operating rooms.

If it is the insulated ground wire (and not the isolated transformer) circuit, I don't see any problem with a using a GFCI receptacle.

Steve
Click to expand...

The way I remember being taught about an isolated ground is that the IG is an insulated grounding conductor separate from the EGC. The IG only connects to the IG terminal of the IG receptacle and that terminal is isolated from the device strap. This is to keep the equipment plugged into the IG system isolated from the EG to prevent interference, stray currents, etc. So for a 120v IG circuit there would be the IGC, EGC, grounded, and non-grounded conductors. Granted it has been 12 years since I learned this stuff and I've actually never had to mess with an IG system so feel free to correct me if I'm off.
 
The GFI recep was specd as was it being an isolated gound.
Our supply house will be getting a call this morning for a couple of the combo units if they are cheaper than a GFI breaker in the panel.
Thanks for the replies.
 
Could you let me know the model number and manufacturer for the IG GFI receptacle. I always had to use a IG receptacle and GFI breaker because I couldn't find a combination one.
 
Supply House screwed up - just found out, when I went to pick them up, that they don't make a ig/gfci - so yes, we will have to use gfci breakers with ig receptacles. Think I need to look for a more knowledgeable supply house.
Again sorry.
 
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