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20A GFCI on 15A circuit

23K views 35 replies 10 participants last post by  ScottR  
#1 ·
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?
 
#2 ·
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.)
 
#4 ·
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..
 
#7 ·
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.
 
#8 ·
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:
 
#21 ·
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
 
#30 · (Edited)
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
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)
 
#22 ·
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..:eek:
 
#23 · (Edited)
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)
 
#32 ·
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:)
 
#35 ·
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.
 
#33 ·
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.
 
#34 ·
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.