Has anoyone ever heard of an isolated ground receptacle that has both an isolated ground screw and a regular ground screw on the receptacle? And if so where can one be found? I have never come accross one I can't find any reference to one and have an engineer insisting they are used.
Isolated Ground Receptacle
- Thread starter gardiner
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RICK NAPIER
Senior Member
- Location
- New Jersey
If the isolated ground goes out to the receptacle ground to feed the appliance what would the other ground bond to? Why are you looking for this?
I have documentation that was done by an engineer that shows this configuration and he insists it exists. I want the documentation changed to reflect what I consider a typical IG receptacle which has one ground screw. However if this does exist I would like to know about it, if this does not exist then I would like to set the documentation straight.
LarryFine
Master Electrician Electric Contractor Richmond VA
- Location
- Henrico County, VA
- Occupation
- Electrical Contractor
Ask for a manufacturer and model.
I've never seen one, but the only thing the second screw could possibly do is bond the yoke (mounting strap), which is usually accomplished by its being mounted to a metal box.
That strap-to-box contact is the reason for the construction of the IG receptacle in the first place. Without it, such as when using NM and plastic boxes, all receptacles are IG.
Believe me the first thing II asked about was who made it, didn?t get an answer except for I saw one once. That?s the reason I asked the question just in case there is or was one out there at one time. I have no desire to commit career suicide, so I wish to cover as many bases as possible, before starting something.
K8MHZ
Senior Member
- Occupation
- Electrician
I am just guessing, but one grounding screw may be on the yoke, the one with the clip to make a good connection to the enclosure. The second would be the green screw, which is not connected to the yoke, making two grounding screws total.
LarryFine
Master Electrician Electric Contractor Richmond VA
- Location
- Henrico County, VA
- Occupation
- Electrical Contractor
Ah, the "we don't need no stinkin' bonding jumper" clip on one mounting 6-32.
Actually, I do remember seeing receptacles that had two EGC terminals, both on the yoke, but they wouldn't be legal to use nowadays, and "aren't the receptacles you're looking for."
LarryFine
Master Electrician Electric Contractor Richmond VA
- Location
- Henrico County, VA
- Occupation
- Electrical Contractor
You might ask what the purpose of the second screw would be.
Plakerio
Member
- Location
- Metro D.C.
250.146 (D) also read the FPN, this is where your second ground comes in. I've installed them a couple of times. Make sure to identify your ground wire or but a roll with a yellow stripe running down the insulation. the receptacles should have an orange triangle on the face of them if I remember correctly.
Mgraw
Senior Member
- Location
- Opelousas, Louisiana
- Occupation
- Electrician
I don't get the need for a second screw either. All the isolated ground receptacles I have seen have a self-grounding yoke. As long as the metal box(if it is metal) has a seperate means of bonding to ground (EMT,AC,etc.) or a second ground wire(MC) the yoke would be bonded to ground.
I should say a second ground on MC is not needed if the MC armor is listed for grounding
I should say a second ground on MC is not needed if the MC armor is listed for grounding
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Do you have any idea who makes them, or if they are even available anymore? I'd really like to see one. Personally I really don't see why you would ever use them seems like a bigger waste of time and effort then installing the IG in the first place.
mivey
Senior Member
The only ones I've seen lately are the ones with the grounding clip on the yoke in addition to the IG screw.
I can't remember what we used back in the 70's but I bet I have a few in the shop somewhere. It has been too long for me to picture the receptacle but I just don't remember the clips on the yoke way back when. Of course, I probably wasn't paying close attention back then either as I was just doing what I was told.
LarryFine
Master Electrician Electric Contractor Richmond VA
- Location
- Henrico County, VA
- Occupation
- Electrical Contractor
If the wiring method is metallic, the non-IG metallic parts are already bonded. If it isn't, there's no need for the IG.
mivey
Senior Member
Doesn't the yoke have to be bonded with a listed means as well or use plastic screws and covers?
Plakerio
Member
- Location
- Metro D.C.
I actually never seen one with two screws on the receptacle. I have seen them with a tail that was the IG and a screw on the yoke. But it servers the same purpose as having two ground screws without trying to confuse anyone with actually having two ground screws
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the times I have seen an IG used was for the government. they wanted a "clean" power outlet for the computers and such, then a "dirty" power outlet next to that for the lighting and everything else. As to who carries them every electrical supplier in my area carries them or can have them within the week. should be the same for your neighborhood.
Whoever the EE is that wants two ground screws on the same device is asking for trouble when it comes to actually installing. the dumber the better, at least for me that is.
.the times I have seen an IG used was for the government. they wanted a "clean" power outlet for the computers and such, then a "dirty" power outlet next to that for the lighting and everything else. As to who carries them every electrical supplier in my area carries them or can have them within the week. should be the same for your neighborhood.
Whoever the EE is that wants two ground screws on the same device is asking for trouble when it comes to actually installing. the dumber the better, at least for me that is.
Thanks for all your responses. My regular suppliers have all come back with a negative on finding the IG receptacle with two screws. Which putting what I learned here and what they are saying I should have enough ammunition to change the work orders to a more conventional receptacle and save everyone a big headache.
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