# 15a vs 20a outlets??



## mopowers (Jul 20, 2009)

So I plan on adding some outlets to an exisitng 20 amp circuit in my garage. Since 15 amp duplex outlets have a rating of 20 amp pass through, should I use those, or should I use 20 amp outlets?

Also what happens if a 15 amp duplex outlet is installed on a 20 amp circuit and the outlet is overloaded? Say I plug a 120v welder that pulls 18 amps into it?

Sorry for the repeated stupid questions.


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## bobelectric (Mar 3, 2007)

A 120 volt appliance rated at 18 amps would have a 20 amp attachment cap on it. I would use all 20 amp gfi"s in the garage.


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## mopowers (Jul 20, 2009)

bobelectric said:


> A 120 volt appliance rated at 18 amps would have a 20 amp attachment cap on it. I would use all 20 amp gfi"s in the garage.


I'm sorry, but what is an attachment cap?


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## Scuba_Dave (Jan 16, 2009)

Any device that MUST be plugged into a 20a circuit/outlet will have a special plug on it

It would require an outlet that matches that plug -

This outlet takes both the normal plug, then a 20a - the one with the blade orientated sideways


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## secutanudu (Mar 15, 2009)

Can you safely put a normal single-pole 15A switch on a 20A circuit with 12AWG wire?


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## Scuba_Dave (Jan 16, 2009)

secutanudu said:


> Can you safely put a normal single-pole 15A switch on a 20A circuit with 12AWG wire?


Yes, as long as the switch Load is under 15a


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## bobelectric (Mar 3, 2007)

Attachment cap is the male plug on a cord.Receptacles are sometimes called "wallplugs".


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## mopowers (Jul 20, 2009)

Since I haven't even seen a tool that I may need to use in the future with a '20a specific' plug, I should be okay with using 15a outlets instead of 20a outlets.

Is there any other reason I should install 20a outlets instead of the cheaper 15 outlets?

Sorry if I'm being redundant. It just seems like the logical thing to do would be to install 20a outelts since the circuit is rated for 20 amps. But, by the sounds of it, there is no reason for me to use 20a outlets.


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## mopowers (Jul 20, 2009)

bobelectric said:


> Attachment cap is the male plug on a cord.Receptacles are sometimes called "wallplugs".


Ahhhh- I see.. Thank you for the explanation!


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## bobelectric (Mar 3, 2007)

mopowers said:


> Ahhhh- I see.. Thank you for the explanation!


 Good. Don't forget about the gfci's.


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## Scuba_Dave (Jan 16, 2009)

mopowers said:


> Is there any other reason I should install 20a outlets instead of the cheaper 15 outlets?


I have a few 20a GFCI's I will install in my garage, just in case
Also a few true 20a outlets
But most will be 15a - but not the cheaper ones...the next step up


I think even under 2005 GFCI was required in the garage
But there was an exception for an outlet that would be behind a fridge/freezer
So your outlet may have been allowed on that basis
That exception was eliminated in 2008


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## micromind (Mar 9, 2008)

15 amp receptacles can be installed on 20 amp circuits, with one exception. If the circuit is 20 amp, and there's only one single receptacle, it must be 20 amp. 

If there's one or more duplex, they can be 15 or 20 amp. 

Here's an example, the receptacles in your kitchen and laundry room are almost certainly supplied by 20 amp circuits. But they're almost certainly 15 amp receptacles. And the electrical passed inspection.

Rob


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## mopowers (Jul 20, 2009)

Thanks for the help guys. I'll go ahead and just install the 15a receps since I know I'll never use a tool that will require a 20amp outlet. I will also install a 15 amp gfci as the first recep in the chain. Thanks again.


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## secutanudu (Mar 15, 2009)

mopowers said:


> Thanks for the help guys. I'll go ahead and just install the 15a receps since I know I'll never use a tool that will require a 20amp outlet. I will also install a 15 amp gfci as the first recep in the chain. Thanks again.


Sounds like a good plan to me.


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## Speedy Petey (Feb 1, 2004)

Rudeboy said:


> Dude, what kind of receptacle is that? Is it a receptacle with plate combo? What's up with the screws? Maybe you found this image on google?


I would assume he did.

That is a mobile home "boxless" device.


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## Speedy Petey (Feb 1, 2004)

mopowers said:


> Thanks for the help guys. I'll go ahead and just install the 15a receps since I know I'll never use a tool that will require a 20amp outlet. I will also install a 15 amp gfci as the first recep in the chain. Thanks again.


I would still get spec-grade devices. Do not use cheap $.49 receptacles in a garage. You WILL be replacing them in short order. 

I use only spec-grade in all locations now.


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## mopowers (Jul 20, 2009)

Speedy Petey said:


> I would still get spec-grade devices. Do not use cheap $.49 receptacles in a garage. You WILL be replacing them in short order.
> 
> I use only spec-grade in all locations now.


What are 'spec-grade' receptacles?


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## Jim Port (Sep 21, 2007)

Spec grade are a more heavy duty type of device. Normally the materials used are tougher or a higher quality. The wires secure using clamps instead of just screws or the back stabs. They also cost more.


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## secutanudu (Mar 15, 2009)

Jim Port said:


> The wires secure using clamps instead of just screws or the back stabs.



This alone makes it worth it. Those clamps are SO much easier and more likely to hold for a long time.


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## Speedy Petey (Feb 1, 2004)

I prefer the ones without the clamps. I like regular screws.

Spec-Grade also have MUCH better plug retention. Meaning plugs will not fall out after a few years of typical use.


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## mopowers (Jul 20, 2009)

Thanks guys. I actually just got back from the store. I ended up picking up 20a outlets and a 20a gfci outlet. The price difference was negligible.

This thread got me thinking though. Is it against NEC to use a 20a receptacle on a 15a circuit? I would think not, but it's probably not a good practice.


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## Scuba_Dave (Jan 16, 2009)

mopowers said:


> This thread got me thinking though. Is it against NEC to use a 20a receptacle on a 15a circuit? I would think not, but it's probably not a good practice.


You can use a 15a (20a pass thru) on a 20a circuit
You can't use a 20a outlet on a 15a circuit
An item that requires a 20a circuit & has the 20a plug requires a 20a circuit
Allowing a 20a outlet on a 15a circuit would defeat that "feature"


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## mopowers (Jul 20, 2009)

Scuba_Dave said:


> You can use a 15a (20a pass thru) on a 20a circuit
> You can't use a 20a outlet on a 15a circuit
> An item that requires a 20a circuit & has the 20a plug requires a 20a circuit
> Allowing a 20a outlet on a 15a circuit would defeat that "feature"


Thanks! I just had an extra 20a outlet. And since I'm adding another outlet in another room, I thought I could go ahead and use it even though the circuit is a 15 amp circuit. I guess I can't though. Looks like another trip to the home improvement store is in order.

Thanks again.


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