# 20A GFCI on 15A circuit



## ScottR (Oct 6, 2008)

> What are the ramications of having a GFCI rated higher than the circuit?


AFAIK it can't hurt, and will still provide protection.



> I've already told my wife she's not allowed to plug a blow dryer into the GFCI.


Ugh. I grew up in a house like that.. if my mom & sister used blow dryers @ the same time, half the 2nd floor would go out. :huh:

(And the bathroom receptacles were integrated into the light fixtures.. double ugh.)


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## jerryh3 (Dec 10, 2007)

jheavner said:


> My bathroom has a 20A GFCI on a 15A circuit. I understand that code says I need 20A and nothing else can share the circuit but that's not the case. I have several bedrooms on this same 15A circuit. Running a 20A circuit to the bathroom is in the planning stages but it's not going to happen immediately. In the meantime should I replace the 20A GFCI with a 15A GFCI? Does it really matter? I understand there's a lot of evil, what's the lesser of the evils here?
> 
> Please don't just recite code to me. I've got thousands of dollars worth of electrical problems that need fixed and unfortunately, some of this is going to be code unfriendly for a bit. I've already told my wife she's not allowed to plug a blow dryer into the GFCI. What are the ramications of having a GFCI rated higher than the circuit?


Why wouldn't she be allowed to use the blow dryer on the GFCI?


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## ScottR (Oct 6, 2008)

jheavner said:


> I've already told my wife she's not allowed to plug a blow dryer into the GFCI.





jerryh3 said:


> Why wouldn't she be allowed to use the blow dryer on the GFCI?


Ah, I think I misunderstood the reason for telling her not to plug it in there..

It would be safe for her to use the dryer on the 20A receptacle / 15A circuit.. I thought the concern was that because many things are on that circuit, she'd be tripping the breaker..


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## jheavner (Sep 1, 2008)

jerryh3 said:


> Why wouldn't she be allowed to use the blow dryer on the GFCI?


I think some of the leaf blowers disguised as blow dryers can pull more than 15A. My thinking is that the circuit trips at 15A and I have to run to the basement to restore power to our upstairs. I don't want to have to set the times on all our various clocks after a reset.


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## Termite (Apr 13, 2008)

A 20amp receptacle can be installed and used on a 15amp circuit with no hazard and no need to correct. It isn't a problem. The receptacle is rated for 20amps, and the breaker on this particular circuit will not supply more than 15amps.


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## handyman78 (Dec 29, 2007)

jheavner said:


> I understand that code says I need 20A and nothing else can share the circuit but that's not the case. I have several bedrooms on this same 15A circuit.


That may be the current code but many homes (including mine) are wired that way and will stay that way unless renovated. Is it out of code? Sure by today's standards but if that were the case every home having knob and tube or aluminum wiring might need to be fully rewired. A good idea but not unless major construction is involved.
Safe vs current code becomes the issue.


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## Termite (Apr 13, 2008)

The hair dryer alone won't trip it, but combined with the lighting, fart fan, and miscellaneous use load in the other rooms...Well, you know. 

I've been where you are for sure! I've had to shower or go #2 in the dark a number of times after our overloaded circuit would trip. Now that I have a dedicated receptacle circuit for my wife's bathroom, the hairdryer is no problem. :thumbsup:


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## jheavner (Sep 1, 2008)

handyman78 said:


> That may be the current code but many homes (including mine) are wired that way and will stay that way unless renovated. Is it out of code? Sure by today's standards but if that were the case every home having knob and tube or aluminum wiring might need to be fully rewired. A good idea but not unless major construction is involved.
> Safe vs current code becomes the issue.


Yeah, but unfortunately for me, this bathroom was renovated and therefore needed to be brought up to code at that time and that didn't happen. I'm assuming that puts me on the hook to correct if I ever plan to sell the house.


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## jheavner (Sep 1, 2008)

thekctermite said:


> A 20amp receptacle can be installed and used on a 15amp circuit with no hazard and no need to correct. It isn't a problem. The receptacle is rated for 20amps, and the breaker on this particular circuit will not supply more than 15amps.


Excellent, that was the answer I was searching for. Out of curiosity, what happens if I plug something in with the "T" that only fits in a 20A receptacle? Will it work? I don't have any plans to do so but I wonder about things like that.


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## jbfan (Jul 1, 2004)

jheavner said:


> Excellent, that was the answer I was searching for. Out of curiosity, what happens if I plug something in with the "T" that only fits in a 20A receptacle? Will it work? I don't have any plans to do so but I wonder about things like that.


If it pulls more than 15 amps, then you trip a breaker.
You will find very fews things to be used in a home with a 20 amp plug.


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## rgsgww (Jul 5, 2008)

jbfan said:


> You will find very fews things to be used in a home with a 20 amp plug.


Defiantly, the only thing ive ever used that has a t plug (i guess nema 5-20p is more accurate) is my computer, and it will never use that many amps anyways.


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## Speedy Petey (Feb 1, 2004)

thekctermite said:


> A 20amp receptacle can be installed and used on a 15amp circuit with no hazard and no need to correct. It isn't a problem. The receptacle is rated for 20amps, and the breaker on this particular circuit will not supply more than 15amps.


Actually is IS a violation to install a 20A receptacle on a 15A circuit. 

That said, the other replies here are true. Even thought it is a technical violation there is no danger in this situation.


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## chris75 (Aug 25, 2007)

Speedy Petey said:


> Actually is IS a violation to install a 20A receptacle on a 15A circuit.
> 
> That said, the other replies here are true. Even thought it is a technical violation there is no danger in this situation.


This is only true if it is two or more receptacles. :thumbup:


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## HouseHelper (Mar 20, 2007)

chris75 said:


> This is only true if it is two or more receptacles. :thumbup:


I believe you are confused. You can put a 15A receptacle on a 20A circuit if you have two or more, but you cannot put a 20A receptacle on a 15A circuit, no matter how many you have.

But as others have said, in this case, you can live with it until the correction is made.


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## chris75 (Aug 25, 2007)

HouseHelper said:


> I believe you are confused. You can put a 15A receptacle on a 20A circuit if you have two or more, but you cannot put a 20A receptacle on a 15A circuit, no matter how many you have.
> 
> But as others have said, in this case, you can live with it until the correction is made.


 
Nope, not confused brother, I can easily install a 20 amp *single* receptacle on a individual 15 amp circuit.

Check out 210.21(B)(1) and read it about 20 times... Bawhahahah...:thumbsup:


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## Termite (Apr 13, 2008)

I've been accused of being unreasonable from time to time on inspections, but that's one thing I'd never turn somebody down for (20 amp rated receptacles on 15 amp circuits). 

I just have a hard time figuring out the hazard.


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## handyman78 (Dec 29, 2007)

jbfan said:


> You will find very fews things to be used in a home with a 20 amp plug.


Correct and certainly not one to plug in a bathroom! :wink:
I'm thinking of compressors, air conditioners, high draw items.


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## chris75 (Aug 25, 2007)

thekctermite said:


> I've been accused of being unreasonable from time to time on inspections, but that's one thing I'd never turn somebody down for (20 amp rated receptacles on 15 amp circuits).
> 
> I just have a hard time figuring out the hazard.


Its not a hazard, but lets play fair, a violation is a violation.


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## HouseHelper (Mar 20, 2007)

chris75 said:


> Nope, not confused brother, I can easily install a 20 amp *single* receptacle on a individual 15 amp circuit.
> 
> Check out 210.21(B)(1) and read it about 20 times... Bawhahahah...:thumbsup:


 It only took once. I'll blame it on a senior moment.:icon_redface:


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## Speedy Petey (Feb 1, 2004)

Sorry Chris, you are wrong on this one. 

Go back and re-read the two charts very closely.
The first column in Table 210.21(B)(2) is the *circuit* rating, not the receptacle rating.

Synopsis:

Total Cord-and-Plug-Connected Load
Table 210.21(B)(2)
*Circuit* rating: 15 or 20, *Receptacle* rating: 15A, maximum c&p connected load:12A

Receptacle Ratings
Table 210.21(B)(3)
*Circuit* Rating: 15A, *Receptacle* Rating: NOT OVER 15A
*Circuit* Rating: 20A, *Receptacle* Rating: 15A or 20A


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## ScottR (Oct 6, 2008)

I'm looking at the code (2008), and the text of 210.21(B)(3) says "Where connected to a branch circuit supplying two or more receptacles or outlets, receptacle ratings shall conform to the values listed in Table 210.21(B)(3) [...]"

So wouldn't that imply that if it were 1 receptacle on 1 circuit, the table is irrelevant, and 20A recep. on a 15A circuit is OK?

I'm confused anyway because 210.21(B)(3) allows a 50A recep. on a 40A circuit, but not a 20A on 15A circuit. But it allows a 15A recep. on a 20A circuit, which is counter intuitive..


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## Speedy Petey (Feb 1, 2004)

Yes, a GFI is "more than one receptacle". It is TWO receptacles outlets in one device. 

This is why a SINGLE, or simplex, receptacle is dual slotted for 15 & 20 amps. Both 120v and 240v come like this. NEC 210.21(B)(1)


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## ScottR (Oct 6, 2008)

> Are you sure. The code says a single receptacle must have an ampacity not less than the rating of OPD.


If the receptacle is 20A and the OCPD is 15A, then it would be OK according to the above..


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## Speedy Petey (Feb 1, 2004)

Scott, there was just a post there by Jerry @9:51pm that disappeared. Creepy.


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## jerryh3 (Dec 10, 2007)

Speedy Petey said:


> Scott, there was just a post there by Jerry @9:51pm that disappeared. Creepy.


Jerry learned how to read and corrected his post.


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## ScottR (Oct 6, 2008)

Me said:


> So wouldn't that imply that if it were 1 receptacle on 1 circuit, the table is irrelevant, and 20A recep. on a 15A circuit is OK?





Speedy said:


> Yes, a GFI is "more than one receptacle". It is TWO receptacles outlets in one device.


I retract my previous statement... :icon_redface:


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## ScottR (Oct 6, 2008)

> Scott, there was just a post there by Jerry @9:51pm that disappeared. Creepy.


I saw it, but I guess Jerry's solved the mystery.. I thought that was weird too.


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## chris75 (Aug 25, 2007)

okay, what did I miss? All I am saying was that if I install a 20 amp *single *receptacle on a 15 amp *individual *circuit, that it meets code, 210.21 (B)(1) allows this. You dont need to read anything else BUT 210.21 (B)(1) because the other sections do not apply.


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## chris75 (Aug 25, 2007)

Speedy Petey said:


> Sorry Chris, you are wrong on this one.
> 
> Go back and re-read the two charts very closely.
> The first column in Table 210.21(B)(2) is the *circuit* rating, not the receptacle rating.
> ...


I'm not wrong and I can prove it.  First off, why are you even looking at tables (B)(2) and (3) ? Read (B)(1)


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## chris75 (Aug 25, 2007)

Probably never have even mentioned it anyhow, just going to add confusion since most DIY's dont understand the difference between a single receptacle and a duplex receptacle. Sorry for the game delay, play on!


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## ScottR (Oct 6, 2008)

> Probably never have even mentioned it anyhow, just going to add confusion since most DIY's dont understand the difference between a single receptacle and a duplex receptacle.


Ah, but now we do, so it was all worth it.. 

(BTW - I've been receptacle device shopping often enough that I knew the diff, I just didn't realize the NEC was so picky. :jester: And does this mean I have to call them "receptacle device" in all my postings from now on when I mean the unit, regardless of single, duplex or triplex??? :jester


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## Speedy Petey (Feb 1, 2004)

Holy crap. Sorry Chris. 
I totally spaced on the fact that you are talking about a single receptacle. I was concentrating on the fact that the OP has a GFI, which is why I concentrated on tables (B)(2) and (3). :icon_redface:

Sorry about that bud.


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## chris75 (Aug 25, 2007)

Speedy Petey said:


> Holy crap. Sorry Chris.
> I totally spaced on the fact that you are talking about a single receptacle. I was concentrating on the fact that the OP has a GFI, which is why I concentrated on tables (B)(2) and (3). :icon_redface:
> 
> Sorry about that bud.


 
No biggie, its a DIY site, I know I think a little differently when reading some of the posts.


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## chris75 (Aug 25, 2007)

ScottR said:


> Ah, but now we do, so it was all worth it..
> 
> (BTW - I've been receptacle device shopping often enough that I knew the diff, I just didn't realize the NEC was so picky. :jester: And does this mean I have to call them "receptacle device" in all my postings from now on when I mean the unit, regardless of single, duplex or triplex??? :jester


 

If you really wanna learn some quick stuff, read thru the Art. 100 Definitions, it will help greatly. Its exactly why some things can be so confusing sometimes.


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## ScottR (Oct 6, 2008)

> If you really wanna learn some quick stuff, read thru the Art. 100 Definitions


That's where I went right before I posted "I retract my previous statement". Wanted to make sure I was wrong..


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