# Pass-through outlets on 20A circuit



## NJMike (Dec 11, 2016)

Hi all,

Kitchens are pretty typically wired with a 20A circuit having a row of 15A outlets, maybe with a 20A GFCI at the beginning of the run sometimes. 

Are 15A outlets *always* ok to run in series on a 20A circuit? Is there any way to check? They are not going to overheat if your toaster oven and blender combine to 17A? 

Leaving aside the safety concern raised by Toasting While Intoxicated.


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## readydave8 (Sep 20, 2009)

NJMike said:


> Hi all,
> 
> Kitchens are pretty typically wired with a 20A circuit having a row of 15A outlets, maybe with a 20A GFCI at the beginning of the run sometimes.
> 
> ...


I don't think you know enough to ask these questions, study up and try again.


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## readydave8 (Sep 20, 2009)

whoops that might have been rude, I was thinking DIY but see you are a HI, sorry


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## PlugsAndLights (Jan 19, 2016)

What you're describing is not allowed in Canada and I doubt it's allowed there 
either. Every receptacle on a 20A cct must be rated for 20A. Commonly known 
as T-slots and more correctly id'd as 5-20R. 
The locations where GFI's are required varies based on local code. Up here every 
receptacle within 1.5m of sink lip must be GFI or GFI protected. 
There's also a max # of 2 outlets per cct for kitchen counters, as per the CEC.
Don't know if NEC is the same. 
P&L


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## PlugsAndLights (Jan 19, 2016)

One other thought: It's reasonably easy to know if it meets todays code. More
difficult to know if met the code that applied when the work was done. Upgrading 
everything to current standards would not be practical.
P&L


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## LGLS (Nov 10, 2007)

PlugsAndLights said:


> What you're describing is not allowed in Canada and I doubt it's allowed there
> either. Every receptacle on a 20A cct must be rated for 20A. Commonly known
> as T-slots and more correctly id'd as 5-20R.


That is not true in the States. 15a rated receptacles are permitted on 20a circuits in the kitchen on the SABC as well as anywhere else in the residence. The only time a 20a rated receptacle with the T slot is required is if it's a singlex receptacle on a dedicated 20a circuit, typically used for window or through-wall a/c units. 

The washer/dryer (if gas) would also demand the same treatment, though I've seen 15a duplexes used in those instances far more often than singlex 20a devices.

The NEC recognizes that whether a device is stamped 15a or 20a, it refers to the NEMA configuration and not the internals of the device, which is the same whether rated for 15 or 20 amps.


> The locations where GFI's are required varies based on local code. Up here every
> receptacle within 1.5m of sink lip must be GFI or GFI protected.
> There's also a max # of 2 outlets per cct for kitchen counters, as per the CEC.
> Don't know if NEC is the same.
> P&L


No we differ there to. Two 20 amp SABC (small appliance branch circuits) are all that's required to satisfy the code, and those 2 may cover the entire kitchen regardless of the quantity of receptacles, as well as feed the dining room, dinette, breakfast nook, "eat-in area" and pantry. No 15a receptacle circuits are allowed except a single dedicated 15a circuit may be ran for the refrigerator only IF you desire.

Our code is simply reflecting the fact that whether your kitchen is 100 sq. ft. or 500 sq. ft, isn't going to change how much coffee you brew, how much toast you eat, or how many smoothies you blend.

So to sum up, 15a duplexes in the kitchen on a 20a circuit are just fine. 2 20a SABCS have been in our code since the early 60's. GFCI protection within 6' of the sink came into being in the mid 80's, that was extended to all kitchen receptacles sometime since then.


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## PlugsAndLights (Jan 19, 2016)

Thanks LGLS. Some of your rules make more sense to me than some 
of ours. Too bad I can't pick and choose. 
P&L


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## MechanicalDVR (Dec 29, 2007)

PlugsAndLights said:


> Thanks LGLS. Some of your rules make more sense to me than some
> of ours. *Too bad I can't pick and choose*.
> P&L


In a perfect world.


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## NJMike (Dec 11, 2016)

Hey Dave, that's OK, you correctly identified me as not knowing enough to be an electrician, which is exactly right. I agree it's not a good idea to give advice to DIYers on these sort of things. 

I feel pretty justified as an HI to come on here and bug you guys, since it may help to reduce the number of homeowners who accost you with dumb recommendations from HIs! 

So it looks like: In the USA it is ok to have 15A outlets on a 20A circuit. This appears to be a very common setup anyway and I should not flag it as a defect. 

Meanwhile I sort of like the Canadian rule better... our setup means you could potentially run more than 15A through a 15A outlet if enough load is plugged in downstream. I don't know if that is really a true concern or not, but it doesn't seem right.

I will be avoiding use of the word "code" with clients for the reason P&L mentions: It only needs to be up to code when the place was built, but then again there are several exceptions, and then on top of that who knows what the local municipal inspector is going to say. In effect whatever that guy chooses to enforce is really "code".


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## macmikeman (Jan 23, 2007)

Even though it is not really code, most local inspectors here will request you use a twenty amp commercial grade outlet on commercial jobs, and it is one of the more common specifications I see on commercial job prints anyway. Same thing for switches, if you use a 15 amp resi grade switch on a commercial buildout you probably are going to be told to replace it with a 20 amp commercial grade device before any final inspection is passed and closed out. 

Its something I wouldn't even bother to argue with an inspector over. Code or no code.


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## don_resqcapt19 (Jul 18, 2010)

NJMike said:


> ...
> So it looks like: In the USA it is ok to have 15A outlets on a 20A circuit. This appears to be a very common setup anyway and I should not flag it as a defect.
> 
> Meanwhile I sort of like the Canadian rule better... our setup means you could potentially run more than 15A through a 15A outlet if enough load is plugged in downstream. I don't know if that is really a true concern or not, but it doesn't seem right.
> ...".


All listed 15 amp receptacles are listed for use on 20 amp circuits and are listed for "feed through" on 20 amp circuits. The internal conductive parts of 15 and 20 amp receptacles are identical. Only the face is different.


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## readydave8 (Sep 20, 2009)

NJMike said:


> Hey Dave, that's OK, you correctly identified me as not knowing enough to be an electrician, which is exactly right. I agree it's not a good idea to give advice to DIYers on these sort of things.
> 
> I feel pretty justified as an HI to come on here and bug you guys, since it may help to reduce the number of homeowners who accost you with dumb recommendations from HIs!
> 
> ...


Thanks for how you handled my response

So I'm thinking about a 20 amp circuit with 20 amp receptacles, plug in a space heater or two and coffee maker and toaster oven, not any different then if they had been 15 amp receptacles which, as Don said, are designed for 20 amp feed through


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## Speedy Petey (Jan 10, 2007)

PlugsAndLights said:


> Thanks LGLS. Some of your rules make more sense to me than some
> of ours. *Too bad I can't pick and choose. *
> P&L


Ha! Some inspectors do. 
Mac's reply above is proof.


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## readydave8 (Sep 20, 2009)

When we change out old fuse boxes it is not unusual to find 30 amp screw-in glass fuses protecting 14 guage wire, obviously we use 15 amp breaker in new panel

So a few years ago, customer called the day after changeout, said a circuit was tripping breaker. I asked him which circuit:

"The one with 2 freezers, refrig, and window unit air cond."


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## splatz (May 23, 2015)

Don't forget about these 










but what are you going to do, install these?


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## Bird dog (Oct 27, 2015)

FWIW the better install IMO is to pigtail the receptacles too.


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## NJMike (Dec 11, 2016)

Well if 15A receptacles are always ok for 20A pass through, with identical interior parts, then it's really never an issue. Now I could have a problem if I get hired to inspect homes in Quebec but I figure that's not too likely...

Although, I wonder what it's like to go through one of those apartment buildings in Quebec City that was built in the 1600's....


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## chknkatsu (Aug 3, 2008)

if you pigtail outlets even if there is more than 15A on the neut the outlet wont see it. but i know most houses are NOT pigtailed


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## Rodger (Jan 3, 2017)

chknkatsu said:


> if you pigtail outlets even if there is more than 15A on the neut the outlet wont see it. but i know most houses are NOT pigtailed



It's been standard practice at both the companies I've worked for to pigtail 20A circuits (unless it's an AFCI or GFCI receptacle protecting other devices down stream.) But I can't say I never serviced a 20A circuit that wasn't pigtailed.


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## swimmer (Mar 19, 2011)

NJMike said:


> Hi all,
> 
> Kitchens are pretty typically wired with a 20A circuit having a row of 15A outlets, maybe with a 20A GFCI at the beginning of the run sometimes.
> 
> ...


I think the code article is Table 210.21(B)(3)
Receptacle Ratings. 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)

I'm not sure whether Table 210.21(B)(2) applies to the load plugged into the receptacle or the current that passes through it on the way to other receptacle(s), or both.

If you pigtail, you can avoid passing current though the receptacle.


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