15A outlets on 20A circuits

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Last week, I posted about running 12/2 wire for a kitchen reno. Well all the circuits are run. I decided on running all 12/2 instead of 12/3 and splitting circuits. Looking ahead to outlets, had a question. I think I know the answer, but just wanted to confirm.
I ran 4 new circuits for the fridge, microwave/range hood, and counter outlets. Am I allowed to use regular 15A outlets? For the counter outlets, I am using regular 15A Decora and GFI's, and for the fridge, microwave just wanted to use regular outlets, like the kind you can get a 10Pk for like $5 at Lowes.
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15 amp outlets are fine. The refrigerator doesn't need to be GFCI protected, but all the counter outlets do. A 15 amp GFCI outlet has a 20 amp feed through
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Just to clarify. A single 15 amp outlet can't be installed on a 20 amp dedicated circuit, but a duplex is fine

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.
This is another example of things in the code that don't seem to make any sense, at least to me. If one can install multiple 15 amp outlets on a 20 amp circuit, why the restriction on installing just one?
And while we're at it, the code also says you can use a 20 amp single outlet on a 15 amp circuit, but you can't install multiple 20's on a 15 amp circuit.
Why the big distinction between single versus multiple outlets?
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On Oct 12, 8:56 am, snipped-for-privacy@optonline.net wrote:

...
I would ASSume because that if you were drawing, say, 18A on a circuit that only had one 15A single receptacle on it, it'd be a fair bet that it was whatever was plugged into that recep that was drawing all that current. However, with a *duplex* recep that is not necessarily the case.
nate
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om...
But let's say you have a coffee maker and a toaster plugged into one 15A duplex, and both are being used at the same time. Obviously now you are drawing more than 15A. Can the duplex handle that? Is each outlet rated for 15A, or is the entire device rated for 15A?
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On 10/12/2010 8:43 AM, Mikepier wrote:

they been handling it for years in every house i've ever seen. I've never seen a 20a outlet installed. Ever.
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Steve Barker
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Mikepier wrote:

To make sure the distinction is clear, if you have a 20A circuit and there is only a single receptacle (not duplex) on the whole circuit it can't be a 15A one. If it was, the receptacle would not allow the circuit to be used at 20A. Wouldn't be the worst thing in the world, but IMHO a reasonable restriction.

You can't install any 20A receptacles on a 15A circuit. If you did, you could plug in devices with a rating of over 15A (has a 20A plug) on the 15A circuit.

Presumably a device with a 15A plug would not draw 18A. A plug-in strip is likely to have a circuit breaker. (You could with an extension cord with 3 outlets.)

Each half is rated 15A and the whole device is rated 20A. Also rated 20A wire-through. (As a practical matter, I suspect it would be hard to make a receptacle that would be OK at 15A but not at 20A.)
--
bud--

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om...
And I have to disagree on that one. I can find the code section for you later, but essentially it comes down to this. The code draws a distinction between circuits with only one outlet and those with more than one. With more than one outlet, it says you can't use a 20A outlet on 15A circuit. But for a circuit with only ONE outlet, the code says the outlet rating must have a current rating at least equal to the circuit rating. Hence, a 20A single outlet can be use on a 15 amp circuit.
I agree that it doesn't make any sense to me. But, at the end of the day, the critical thing is that the circuit breaker be correctly sized.
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snipped-for-privacy@optonline.net wrote:

Most of the thread uses 210.21. It says what you say above, which I agree is odd.
A while back I ran across 406.3-A which, IMHO, prohibits almost all 20A single receptacles on a 15A circuit: 15/20A receptacles "shall be installed only on circuits of the voltage class and current for which they are rated." This applies only to "grounding-type" receptacles, so you presumably could put an ungrounded 20A single receptacle as the only receptacle on a 15A circuit (and only in those cases where you can use an ungrounded receptacle). Oddness remains, but is greatly limited.
--
bud--

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No, it doesn't. Read Table 210.21(B)(3). The permitted receptacle ratings on a 15A circuit are "not over 15". On a 20A circuit, it's "15 or 20".

Never mind that. Table 210.21(B)(3) prohibits *all* 20A receptacles, single or duplex, on a 15A circuit.

No, you can't. 15A circuits may not have receptacles rated over 15A. Period. There are no exceptions.

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On Wed, 13 Oct 2010 02:49:40 GMT, snipped-for-privacy@milmac.com (Doug Miller) wrote:

When you lookk at it logically - from an electrical point of view - it would make more sense to allow a 20 amp receptacle on a 15 amp circuit than the other way around. Look at it from this point of view. A 20 amp receptacle ic designed to handle 20 amp loads - on a 15 amp circuit it is protected to 15 amps. This is definitely safe as nothing can operate above its rated or protected current . A 15 amp receptacle is designed for a 15 amp load and when installed on a 20 amp circuit is protected at 20 amps and wired with wiring that is rated at 20 amps. The receptacle is now the week link, and being somewhat resistive in nature it is succeptible to overload damage if a load plugged into it draws more than it's rated current - as it is "protected" to a current higher than its rating.. This definitely has the possibility of being unsafe as the receptacle can operate above its rated current.
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wrote:

No, it is not "definitely safe". It's of questionable safety at best

No, it can't, because any device that draws enough current to overload a 15A circuit is not permitted to have a plug that will fit into a 15A receptacle. It will have a plug that fits only into 20A receptacles. That's why a 20A receptacle has a different configuration.
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On Thu, 14 Oct 2010 01:10:34 GMT, snipped-for-privacy@milmac.com (Doug Miller) wrote:

You obviously do not understand electrical theory any more than you understand the code book.
You explain to me how a 20 amp receptacle on a 15 amp fused/protected circuit is a safety issue.
Give it your best crack.

No, you are wrong. 100% The fuse is their to prevent damage due to, and protect against FAULT CURRENT. Any device, irregardless of it's rating, can draw excessive current due to a FAULT. And a 15 amp plug fits a 20 amp receptacle.
By your logic, twisted as it is, all 15 amp receptacles on a multi-branch circuit would have to be designed, built, and installed in such a way that if anything was plugged into one receptacle drawing close to 15 amps (or anything with a 15 amp plug, for that matter) , it would be impossible to plug anything else into any other receptacle on the circuit.
That's not the way it works (thankfully), nor should it.
The "ring wiring" system used (at least untill recently) in brittain and some parts of europe makes sense, with fused outlets. There is also a proposed standard (smart home) that would have each plug identify the rated current of the device and centrally monitor the current draw, shutting the device down if current ratings are exceded without shutting down anything else. This system uses RFID chips for identity - and yes - it IS being worked on - I know one of the engineers involved in the project.
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snipped-for-privacy@snyder.on.ca wrote:

trader already did in a perfectly good answer (below).

What a brilliant idea. We can ignore current trips at a little over the circuit rating and just trip on fault current - maybe 80A and higher.

I posted earlier that a 15A duplex receptacle is rated for a total 20A in both halves.
There have been a couple posts that a 15A receptacle is rated 20A wire-through.

You appear to have little idea of "the way it works". Perhaps the cold electrons in Canada behave differently.
Else you should stick to cars. There is no shock hazard and less to burn down.
--
bud--

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wrote:

I don't see anything SAFETY relatee anywhere in trader's post. All he's talking is inconvenience.

Not germain to the discussion at hand. You guys seem to think it's your "god given right" to expect to be able to plug a 15 amp device into any 15 amp receptacle in a building and not have a breaker trip.
That can ONLY happen if every receptacle in the building is a split on a double breaker. I only know of one house where that is the case - every receptacle in the house is a 20 amp, separately supplied direct from one of several 400 amp panels distributed throughout the house. About half of them are also remotely switched. Took a very good electrician several months to wire that monstrosity.

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snipped-for-privacy@optonline.net wrote:

Yeah, you do that. We'll wait.

Wrong. It says you can't use a 20A outlet on a 15A circuit, period. You've apparently become confused by the provision that you can put 15A outlets on a 20A circuit as long as there's more than one outlet. That's perfectly OK. Putting a 20A outlet on a 15A circuit is a violation in all cases, without regard to how many there are.

It says no such thing. It is, for example, a violation to put a 50A outlet on a 20A circuit.

No, it cannot. Look at Table 210.21(B)(3), where it lists the permissible receptacle ratings. For a 15-amp circuit, the maximum receptacle rating is "not over 15".

Doesn't make any sense to me either. Of course, that's because you're completely wrong about the rules.
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On Oct 12, 10:47 pm, snipped-for-privacy@milmac.com (Doug Miller) wrote:

You didn't have to wait long. Here it is. No need to get sarcastic and snippy.
" 210.21 Outlet Devices. (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."
That is clear as day. A 20 amp single receptacle has an ampere rating greater than that of the circuit, hence it MAY be used. If they wanted to prohibit using a 20 amp or greater single receptacle on a 15 amp circuit, all they had to do was say the receptacle has to have a rating EQUAL to the circuit.

Actually it does say exactly what I said it does, as shown above. You're the one who's confused, which is OK, but why the attitude?

Yes, let's look at that section. In the same section where it starts to explain those tables it starts off with:
"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)"
The added emphasis is mine. Since we are talking about using a SINGLE 20 amp outlet on a 15 amp circuit, those tables do NOT apply.

Actually it's quite clear that you're the one who's wrong here. A simple admission to that and apollogy for getting snippy will suffice.
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wrote:

You didn't have to wait long. Here it is. No need to get sarcastic and snippy.
" 210.21 Outlet Devices. (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."
That is clear as day. A 20 amp single receptacle has an ampere rating greater than that of the circuit, hence it MAY be used. If they wanted to prohibit using a 20 amp or greater single receptacle on a 15 amp circuit, all they had to do was say the receptacle has to have a rating EQUAL to the circuit.

Actually it does say exactly what I said it does, as shown above. You're the one who's confused, which is OK, but why the attitude?

Yes, let's look at that section. In the same section where it starts to explain those tables it starts off with:
"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)"
The added emphasis is mine. Since we are talking about using a SINGLE 20 amp outlet on a 15 amp circuit, those tables do NOT apply.

Actually it's quite clear that you're the one who's wrong here. A simple admission to that and apollogy for getting snippy will suffice.
I think the reason for that initial statement in the code, is because a 40 amp receptacle can be wired with a 40 or 50 amp circuit, but the table makes it perfectly clear that a 20 amp receptacle can't be wired with a 15 amp circuit
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That table is preceeded by the statement, which I provided and is shown above, that says it applies to circuits with TWO or more receptacles. If they wanted it to apply to ALL receptacles, including single outlet ones, they could have simply omitted the word TWO, but they did not. And the section right before it clearly covers the case of a SINGLE receptacle and allows a receptacle with a current rating equal to or greater than the circuit to be used.
It doesn't make a lot of sense to me, but that is what it says and it allows using a single 20 amp receptacle on a 15 amp circuit.
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