# Can I protect a two wire circuit with a GFCI?



## nitro71 (Sep 17, 2009)

I'm trying to figure out if it's compliant to protect a two wire 15-20 amp circuit with a GFCI breaker and install three wire receptacles on the circuit.

406.3(D)(C)(3) seems to say I can protect a two wire circuit with a GFCI. Replace the two wire receptacles with three wire and label accordingly.


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## MDShunk (Jan 7, 2007)

Yep. It's just required that you place the "no equipment ground" sticker on each of those receptacles. I'm out and about, so I have no code citation for you. 

Extending that circuit, by chance? That's a no-go, if memory serves.


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## BBQ (Nov 16, 2010)

nitro71 said:


> I'm trying to figure out if it's compliant to protect a two wire 15-20 amp circuit with a GFCI breaker and install three wire receptacles on the circuit.


Yes 406.3(D)(3)(c)



> (c) A non–grounding-type receptacle(s) shall be permitted
> to be replaced with a grounding-type receptacle(s)
> where supplied through a ground-fault circuit interrupter.
> Grounding-type receptacles supplied through the groundfault
> ...



250.114 may limit what you are allowed to plug into the receptacle.


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## 480sparky (Sep 20, 2007)

406.3(d)(3).


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## Rockyd (Apr 22, 2007)

Curses...I was to slow with the book (NEC)...what the above say...


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## nitro71 (Sep 17, 2009)

BBQ said:


> Yes 406.3(D)(3)(c)
> 
> 
> 250.114 may limit what you are allowed to plug into the receptacle.


Thanks for help on this basic question. I just perused 250.114. So it says "likely to become energized". What's that mean? Does that mean every refrigerator is likely to become energized. Or is it unlikely that those appliances would become energized? My vote is unlikely.


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## nitro71 (Sep 17, 2009)

No extension of the circuit. I'm not a huge old work, resi guy, but ran into some two wire receptacles today. Have a concientious seeming customer so seeing if I can upsell some GFCI protection.


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## MDShunk (Jan 7, 2007)

nitro71 said:


> No extension of the circuit. I'm not a huge old work, resi guy, but ran into some two wire receptacles today. Have a concientious seeming customer so seeing if I can upsell some GFCI protection.


Yes, you can. 250.114 just has a list of things that are required to have a "real" ground. That doesn't really effect what you're doing, in all likelihood, unless one of them is (for instance) behind the refrigerator. Doubtful, though, since even houses with 2-prong recs very often had 3-prongers in the kitchen. You're installing receptacles. How they use them is up to the homeowner.


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## BBQ (Nov 16, 2010)

nitro71 said:


> Thanks for help on this basic question. I just perused 250.114. So it says "likely to become energized". What's that mean? Does that mean every refrigerator is likely to become energized. Or is it unlikely that those appliances would become energized? My vote is unlikely.


Basically if the appliance has a grounding conductor in the cord it must be connected to a grounding means at the receptacle.

OSHA will enforce this at a place of business.


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## nitro71 (Sep 17, 2009)

How does a GFCI protect down stream receptacles in a two wire circuit? Since it can't sense a fault to ground on the down stream receptacles? Am I missing something here?


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## nitro71 (Sep 17, 2009)

BBQ said:


> Basically if the appliance has a grounding conductor in the cord it must be connected to a grounding means at the receptacle.
> 
> OSHA will enforce this at a place of business.


 
This is a residence so perhaps not enforced but still good to know.


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## MDShunk (Jan 7, 2007)

nitro71 said:


> How does a GFCI protect down stream receptacles in a two wire circuit? Since it can't sense a fault to ground on the down stream receptacles? Am I missing something here?


If everything that's "leaving" on the hot doesn't "return" on the neutral, it's assumed to be going someplace it shouldn't. If that hot and neutral current imbalance exceeds roughly 4-5ma, it trips.


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## nitro71 (Sep 17, 2009)

Just so I'm crystal clear on this; a GFCI breaker feeding a two wire circuit with multiple three wire outlets(labeled) is compliant. And is this a real benefit to the customer?


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## MDShunk (Jan 7, 2007)

nitro71 said:


> Just so I'm crystal clear on this; a GFCI breaker feeding a two wire circuit with multiple three wire outlets(labeled) is compliant. And is this a real benefit to the customer?


The "real" benefit is the installation of new receptacles that hold the prongs of an attachment cord better. This can be accomplished with new 2-prong receptacles. I have a hard time selling any real benefit from GFCI protection. If you're doing breakers, think about upselling combination GFCI- AFCI's instead.


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## nitro71 (Sep 17, 2009)

MDShunk said:


> The "real" benefit is the installation of new receptacles that hold the prongs of an attachment cord better.


LOL! That's funny. How about a explainable reason to not use those cheater plugs that allow you to plug in a three wire device into a two wire outlet? 

Seems that there would be a benefit should a three wire device become energized. That the GFCI would trip and protect the user.


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## MDShunk (Jan 7, 2007)

nitro71 said:


> LOL! That's funny. How about a explainable reason to not use those cheater plugs that allow you to plug in a three wire device into a two wire outlet?
> 
> Seems that there would be a benefit should a three wire device become energized. That the GFCI would trip and protect the user.


Oh, you're right. It's just that so few things you ordinarily plug in around the house have 3-prong cords. The few things that do probably require a "real" grounded receptacle.


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## BBQ (Nov 16, 2010)

nitro71 said:


> How about a explainable reason to not use those cheater plugs that allow you to plug in a three wire device into a two wire outlet?


Well those are supposed to be grounded. :laughing:


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## nitro71 (Sep 17, 2009)

I'm emailing my customer some information. It's expensive for them if they want to make any real changes. If it were me I wouldn't worry about it but I don't think that's a good professional opinion. Of course the panel is a QO panel ($$ for a GFCI breaker). Suppose that opinion might change if had kids or a wife around those three wire appliances.. hmm.


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## MDShunk (Jan 7, 2007)

nitro71 said:


> Of course the panel is a QO panel ($$ for a GFCI breaker).


Considering that many of these old 2-wire circuits were wired "octopus style", the GFCI breaker is very often a cost savings over the multiple point of use GFCI receptacles you'd otherwise have to use to protect the whole circuit. You never really know until you start to tackle each circuit and get an idea if they were daisy chained or just jumped off here and there.


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## nitro71 (Sep 17, 2009)

Thanks for GFCI school today:thumbup:


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## Jim Port (Oct 1, 2007)

Using the GFI breaker also avoids trying to find the upstream receptacle or trying to fit a GFI receptacle into a small box with the cloth covered conductors and the huge splice.


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## Frasbee (Apr 7, 2008)

So can you simply replace the 2 prong with a GFCI and then 3 prongs thereafter without replacing any wiring? 



> An equipment grounding
> conductor shall not be connected between the groundingtype
> receptacles.


Would that also mean the GFCI itself does not require a ground either to the device box or fuse box?


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## NolaTigaBait (Oct 19, 2008)

Frasbee said:


> So can you simply replace the 2 prong with a GFCI and then 3 prongs thereafter without replacing any wiring?
> 
> 
> Would that also mean the GFCI itself does not require a ground either to the device box or fuse box?


Pretty much...You just can't extend the circuit. The GFI doesn't need a ground connected to it.


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## Speedskater (Oct 2, 2009)

Leviton now lists a smaller dual GFCI receptacle to fit in old boxes.

http://www.leviton.com/OA_HTML/ibeCCtpSctDspRte.jsp?section=33474&minisite=10021


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## Salvatoreg02 (Feb 26, 2011)

Let's clarify something here are we talking about a i12/2 or 14/2 romex with no ground ?


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## nitro71 (Sep 17, 2009)

Salvatoreg02 said:


> Let's clarify something here are we talking about a i12/2 or 14/2 romex with no ground ?


That's correct. Older wiring that doesn't have a ground.


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