# 15 amp receptacles on a 20 amp circuit?



## Gary Arthurs (Dec 22, 2015)

NEC Table 210.24 allows a 15 amp receptacle to be installed on a 20 amp circuit. How is this ok?


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## Meadow (Jan 14, 2011)

20amp feed through rating on both 15 and 20amp versions.


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## 480sparky (Sep 20, 2007)

How many appliances do you own that have 20a cord ends?


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## sbrn33 (Mar 15, 2007)

480sparky said:


> How many appliances do you own that have 20a cord ends?


I own a few


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## RePhase277 (Feb 5, 2008)

Gary Arthurs said:


> NEC Table 210.24 allows a 15 amp receptacle to be installed on a 20 amp circuit. How is this ok?


For one, the appliance that you use on the circuit has a plug on it that is rated in amps. Why would a manufacturer put a 15 amp plug on an appliance that draws 18 amps?

Another thing is, a 15 amp receptacle is rated for 20 amp feedthrough, so that the portion of the circuit downstream from a receptacle can still deliver 20 amps.

In other words, the code is relying on the idea that appliances with 15 amp plugs won't use over 15 amps in the application it was intended for.


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## telsa (May 22, 2015)

Gary Arthurs said:


> NEC Table 210.24 allows a 15 amp receptacle to be installed on a 20 amp circuit. How is this ok?


Because the 15A receptacle is engineered to take// pass// tolerate 20A anyway.

The only NEMA difference between them is pattern -- the plastic opening and the conductor body underneath.

The NEC is oriented towards safety... not 'logical purity.' ( however defined )

&&&

You can trudge through old threads here at ET.

And find this issue utterly beaten to death.


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## oliquir (Jan 13, 2011)

in the cec you cant, with a power strip you can easliy put 20 amp of load on a 15 amp receptacle


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## Dennis Alwon (May 9, 2009)

oliquir said:


> in the cec you cant, with a power strip you can easliy put 20 amp of load on a 15 amp receptacle


The guts of a 15 and 20 amp receptacle are the same . The difference is the slot on the 20 amp receptacle.

Remember if this is a single receptacle being fed from an individual 20 amp circuit then the single receptacle must be 20 amp.



> 210.21 (B) Receptacles.
> (1) Single Receptacle on an Individual Branch Circuit.
> A single receptacle installed on an individual branch circuit
> shall have an ampere rating not less than that of the branch
> circuit.


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## sbrn33 (Mar 15, 2007)

Dennis Alwon said:


> The guts of a 15 and 20 amp receptacle are the same . The difference is the slot on the 20 amp receptacle..


How do you know they are the same? Are you sure there is not just a tad more contact area on a 20? It seems like you and telsa are assuming something that you do not have substantiation for. I have never held a 20 molded plug that did not have a pretty hefty feel.


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## Dennis Alwon (May 9, 2009)

sbrn33 said:


> How do you know they are the same? Are you sure there is not just a tad more contact area on a 20? It seems like you and telsa are assuming something that you do not have substantiation for. I have never held a 20 molded plug that did not have a pretty hefty feel.


I have been told by members at mike holt who have talked with the manufacturers. I believe Don can verify this but I have no first hand knowledge.


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## RePhase277 (Feb 5, 2008)

oliquir said:


> in the cec you cant, with a power strip you can easliy put 20 amp of load on a 15 amp receptacle


I never seen a 15 amp power strip without a circuit breaker.


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## bkmichael65 (Mar 25, 2013)

The 15 amp receptacles are rated to feed through 20 amps, each side of the duplex is only rated for 15 amps


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## Southeast Power (Jan 18, 2009)

Dennis Alwon said:


> The guts of a 15 and 20 amp receptacle are the same . The difference is the slot on the 20 amp receptacle.
> 
> Remember if this is a single receptacle being fed from an individual 20 amp circuit then the single receptacle must be 20 amp.


With that said, you shouldn't buy any 20 amp duplex devices when you trim a house.


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## Speedy Petey (Jan 10, 2007)

It has to be remembered, a 15A duplex is constantly called a "15A device". Thing is, it is TWO 15A receptacles on a common yoke.


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## joebanana (Dec 21, 2010)

bkmichael65 said:


> The 15 amp receptacles are rated to feed through 20 amps, each side of the duplex is only rated for 15 amps


Am I missing something? You can't use a recep. to "feed through" you must pigtail the conductors, especially the neuts.


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## cabletie (Feb 12, 2011)

You can feed through 12 ga on a 15 amp device if you use the screws. You can't back stab 12 ga, the holes are to small on purpose


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## don_resqcapt19 (Jul 18, 2010)

joebanana said:


> Am I missing something? You can't use a recep. to "feed through" you must pigtail the conductors, especially the neuts.


The only code requirement for pigtail is the neutral of a multiwire branch circuit.

I, and others have taken 15 and 20 amp receptacle of the same brand and series apart...the guts are identical. It is just function of manufacturing efficiency....it is easier and more cost effective to make the guts of the two identical. Some manufacture reps have said the same thing.


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## DCprof (Jan 9, 2015)

*20 amp Duplex Receptacles*

The reason the manufacturers do not have back stab connections for #12 solid is that when Aluminum wire was used the smallest size is #12 for 15 amp circuits. to prevent Aluminum connections they only use screw terminals and now COALR type for Aluminum. By using pig tails it puts less stress on the screw terminals that could loosen the screws.


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## don_resqcapt19 (Jul 18, 2010)

DCprof said:


> The reason the manufacturers do not have back stab connections for #12 solid is that when Aluminum wire was used the smallest size is #12 for 15 amp circuits. to prevent Aluminum connections they only use screw terminals and now COALR type for Aluminum. By using pig tails it puts less stress on the screw terminals that could loosen the screws.


The change in the UL standard to prohibit the use of back stab connections for #12 came long after aluminum was off the market in the #10 and #12 sizes. Aluminum conductors in those sizes have been off the market since the mid 70s. I believe the standard was changed to prohibit back stabbed #12 in the late 80s.

It was based on connection failures with the #!2, one of the reason being the additional stiffness of the #12 when you put the receptacle in to the box put pressure on the connection that reduced its current carrying capacity.


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## macmikeman (Jan 23, 2007)

joebanana said:


> Am I missing something? You can't use a recep. to "feed through" you must pigtail the conductors, especially the neuts.


Says who? Spec? Local tradition? Co- workers? Like Don said, multiwire branch circuit neutrals only per NEC.


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## oliquir (Jan 13, 2011)

InPhase277 said:


> I never seen a 15 amp power strip without a circuit breaker.


not really a power strip but those dont have breaker or fuses inside


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## Sparkchaser1 (May 17, 2015)

macmikeman said:


> Says who? Spec? Local tradition? Co- workers? Like Don said, multiwire branch circuit neutrals only per NEC.


I agree with joebananna........maybe it's allowed, but is that the best way to do it? Sometimes this forum is more about "what's the minimum I have to do" or, more often, "what can I get away with". 

Just because something "isn't specified by Code" doesn't mean it isn't a half-ass way to do something.


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## macmikeman (Jan 23, 2007)

Nothing half assed about terminating wiring to screw terminals. UL would thank me for saying so and hit the like button but they are busy right now testing some of the really screwed up wire nut types that have plagued the market with failures, like those hard candy ones that crack in half when the ambient temps and full load current cook the plastic so bad it degrades to mush. 


Get off the soap box.


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## Speedy Petey (Jan 10, 2007)

Sparkchaser1 said:


> I agree with joebananna........maybe it's allowed, but is that the best way to do it? Sometimes this forum is more about "what's the minimum I have to do" or, more often, "what can I get away with".


I hardly think this is true. I think it's more _"What are my options..."_




Sparkchaser1 said:


> Just because something "isn't specified by Code" doesn't mean it isn't a half-ass way to do something.


Well in this case using the screw terminals of a receptacle is perfectly within code, safe, and reliable. Without exaggeration in all my years I have seen as many wire nut failures as I have device screw failures, and in both cases most times the fault was in the installation as opposed to the material. Meaning a loose screw and a loose wire nut will both eventually fail. Basically, do it right the first time and it should never fail.

At the same time there are things that are known failure points even with a perfect installation, such as backstabbed devices. Pretty much everyone agrees this is a sub-standard installation yet is perfectly code complaint.


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## Sparkchaser1 (May 17, 2015)

Well, I've had the exact opposite experience, albeit the fed-through receps were older. Feed-through simply isn't done here and is considered substandard by electricians and AHJ's alike. Perhaps wire nut failures are more common in areas of the country where feed-through is acceptable and therefore pigtailing isn't done as much. The newest building I've seen around here that was fed-through was built in 1969, and even some of that building was pigtailed. So since my use of "half-assed" may have struck a nerve, I'll say "IMO substandard".

I think if more guys saw these installations several years later they'd agree with me.


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## Speedy Petey (Jan 10, 2007)

Sparkchaser1 said:


> Well, I've had the exact opposite experience, albeit the fed-through receps were older. Feed-through simply isn't done here and is considered substandard by electricians and AHJ's alike. Perhaps wire nut failures are more common in areas of the country where feed-through is acceptable and therefore pigtailing isn't done as much. The newest building I've seen around here that was fed-through was built in 1969, and even some of that building was pigtailed. So since my use of "half-assed" may have struck a nerve, I'll say "IMO substandard".
> 
> I think if more guys saw these installations several years later they'd agree with me.


Are you suggesting that those electricians that use side screws as opposed to always pig-tailing somehow don't do very many wire nut splices and are somehow deficient at splicing? Kind of an absurd suggestion, don't you think??
Are receptacle pigtails the only place you use wire nuts?

Maybe your area needs a better class of electrician? Ones that know how to terminate a device properly. :whistling2:


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## theJcK (Aug 7, 2013)

There are 2 reasons I started pigtailing.. it makes trim out faster and it keeps down the line receptacles from failing if one upstream does. But fed-through leads to easy troubleshooting. "Half the plugs dont work you say? Lets look at the last working one first then." 99 out of a hundred theyre backstabbed also.. hooks hardly fail in my experience. Those that do have been wrapped wrong or a hard strip aka terminate improperly.


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## RePhase277 (Feb 5, 2008)

There is nothing to fail with a screw-wired feed-through receptacle. The screws are attached to each other with the brass tab and doesn't depend on the spring pressure of the contacts inside the receptacle. I have seen many failed stab-in devices. I have seen many melted receptacles from loose contacts. I have seen many failed connections that were made improperly. But I have never ever ever seen a failed connection due to the feed-through on the screws if it was done properly to begin with.

The receptacle could melt completely out of the wall and the feed-through connection would still be intact.


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## 480sparky (Sep 20, 2007)

InPhase277 said:


> There is nothing to fail with a screw-wired feed-through receptacle. The screws are attached to each other with the brass tab and doesn't depend on the spring pressure of the contacts inside the receptacle. I have seen many failed stab-in devices. I have seen many melted receptacles from loose contacts. I have seen many failed connections that were made improperly. But I have never ever ever seen a failed connection due to the feed-through on the screws if it was done properly to begin with.
> 
> The receptacle could melt completely out of the wall and the feed-through connection would still be intact.



Nope. Don't believe ya. Impossible. Never can happen.


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## macmikeman (Jan 23, 2007)

480sparky said:


> Nope. Don't believe ya. Impossible. Never can happen.


Don't see a box, so this one don't count.


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## RePhase277 (Feb 5, 2008)

That supports what I said. I bet the receptacles down stream worked just fine. Maybe they still do if the conductors haven't shorted together.:thumbup:


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## 480sparky (Sep 20, 2007)

InPhase277 said:


> That supports what I said. I bet the receptacles down stream worked just fine. Maybe they still do if the conductors haven't shorted together.:thumbup:


We'll never know. POCO shut off power at pole. I came in, meggered all the circuits, and disconnected anything that didn't pass. This was done to get power restored. 

A few days later, I came in and ripped out all the damaged wiring as they HO was getting a whole new kitchen (this was the recep behind the fridge).

So I never bothered to check whether the circuit would still operate, although there were no tripped breakers when I first arrived.



macmikeman said:


> Don't see a box, so this one don't count.


I'll bet you don't see a receptacle either.


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## macmikeman (Jan 23, 2007)

480sparky said:


> We'll never know. POCO shut off power at pole. I came in, meggered all the circuits, and disconnected anything that didn't pass. This was done to get power restored.
> 
> A few days later, I came in and ripped out all the damaged wiring as they HO was getting a whole new kitchen (this was the recep behind the fridge).
> 
> ...


Well, I have eye trouble. What is that thing down on the left of the rat?


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## 480sparky (Sep 20, 2007)

macmikeman said:


> Well, I have eye trouble. What is that thing down on the left of the rat?


Drywall. :laughing:


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## Sparkchaser1 (May 17, 2015)

Speedy Petey said:


> Are you suggesting that those electricians that use side screws as opposed to always pig-tailing somehow don't do very many wire nut splices and are somehow deficient at splicing? Kind of an absurd suggestion, don't you think??
> Are receptacle pigtails the only place you use wire nuts?
> 
> Maybe your area needs a better class of electrician? Ones that know how to terminate a device properly. :whistling2:


Like I said, the fed through receps Ive seen were older. Hundreds of plug in/unplug cycles, and the those repeated movements loosened the screw terminals. But they were old, like the ideas and suggestions of many people. I'm sure you're a great pigtailer, when you choose to do so. 

Obviously I pigtail everything, not just receptacles. It would be absurd not to.

And the majority of electricians in this area are top notch, and they excel at terminating a device. And the ones that are 60 years old and younger don't feed through.


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## readydave8 (Sep 20, 2009)

Sparkchaser1 said:


> Like I said, the fed through receps Ive seen were older. Hundreds of plug in/unplug cycles, and the those repeated movements loosened the screw terminals. But they were old, like the ideas and suggestions of many people. I'm sure you're a great pigtailer, when you choose to do so.
> 
> Obviously I pigtail everything, not just receptacles. It would be absurd not to.
> 
> And the majority of electricians in this area are top notch, and they excel at terminating a device. And the ones that are 60 years old and younger don't feed through.


Yeah, I know, you're Super-Electrician. Congratulations.


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