electric outlet for window AC question

On Thu, 16 Jun 2005 20:53:38 GMT indago wrote: | 050616 0130 - Roy Q.T. posted: | |> NEC 210.21 [(B)(1)] ~ Receptacles: A single receptacle installed on an |> individual branch circuit shall have an ampere rating "not less" than |> that of the branch circuit. |> ?oy |> |> From: snipped-for-privacy@aol.com |> On 8 Jun 2005 04:21:48 GMT, snipped-for-privacy@ipal.net wrote: |> It could just be that I can't find the part of the code that says a 15 |> amp circuit cannot have a 20 amp receptacle |> Look at 210.21(B)(3) again. The top line says 15a circuits shall have |> receptacles "not over 15a" |> | | So, what if you put a 20 Amp duplex receptacle on a 15 Amp branch circuit?

That is not permitted by NEC 210.21(B)(3). See table 210.21(B)(3). But this only applies to circuits with 2 or more outlets. A duplex receptacle is 2 outlets, so it applies. However, I see no rule that would prohibit this for a _single_ outlet circuit.

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| You guys are Bizarre, too inquisitive & argumentative. | | my rebuttal: | | Even if i agreed with the lot of you on each of your noted points, you'd | still think I have a problem understanding this Post or it's Merits and | Solutions. | | With that in mind, The Hell with It., | | I didn't come here to argue over Picky Ninny Engineering Standards that | don't have apparent reason for excising but to arrange arguments over | everything and anything Electrical that is Manufactured. | Some No-Code Literate people think they do the dandiest things with | plugs and receptacles regardless of the NEC or these arguements. | | It's either the Best Solution or I leave it alone.... Teachers think | different from most of you and I don't care., but you told them what & | how you want it & how you made it., not the other way around, You are | All Confusing and wrong about me somehow. I'd swear right back today | }:-p | | Since my expertise is Technical., you just keep giving us the best | designs possible for the best Installation/assembly possible. | | | And Phil; don't harass me any more over what you think I don't | understand, I am not dumb, didn't I spell it out with positive | assertion?, some of you are damn near insulting and inhospitable like in | here ... | some of you are cool, others perhaps just confused about my assertions. | Roy ~ E.E. Tech

The NEC is not just about what is electrically safe. Many rules are about the _practices_ of electrical power installations with regard to making conditions that can stay safe under errant usage and maintenance conditions. Many of the rules are intended to prevent mistakes. An obvious example is the requirements for certain insulation colors on certain conductor types, such as white/gray for neutral, and green for ground. I'm sure you know as well as I do that electrons and magnetic fields don't give a damn whether the neutral wire is insulated with gray or blue or brown insulating material. But making sure an installation is unstandable when maintained is as much of what these rules are about as anything else. And sometimes it just does not make a lot of sense until you look at things in the context of what happens when someone else comes along to do maintenance or upgrades on the work you originally did. They need to be able to understand enough of it to be sure that mistakes cannot be made (such as connecting a hot wire with white color insulation to the neutral terminal of a new receptacle) unsafe.

I don't always see those rules for what they are myself. So sometimes I have to push people to get an explanation. Sometimes no one really knows why a given "stupid" rule is there. There must be a reason. If after extensive questioning of many people, no reasonable explanation is found, submit a proposed change (to undo that rule) to the appropriate NEC committee and see what their rsponse is. They might include a reason for not changing it. Or they might change it.

But your instance that 15 amp receptacles are not permitted on 20 amp circuits despite a clear and obvious NEC rule that allows it, is not earning you any credibility here.

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phil-news-nospam

From: snipped-for-privacy@ipal.net On Thu, 16 Jun 2005 18:17:57 -0400 Roy Q.T. wrote: | You guys are Bizarre, too inquisitive & argumentative. | | my rebuttal: | | Even if i agreed with the lot of you on each of your noted points, you'd | still think I have a problem understanding this Post or it's Merits and | Solutions. | | With that in mind, The Hell with It., | | I didn't come here to argue over Picky Ninny Engineering Standards that | don't have apparent reason for excising but to arrange arguments over | everything and anything Electrical that is Manufactured. | Some No-Code Literate people think they do the dandiest things with | plugs and receptacles regardless of the NEC or these arguements. | | It's either the Best Solution or I leave it alone.... Teachers think | different from most of you and I don't care., but you told them what & | how you want it & how you made it., not the other way around, You are | All Confusing and wrong about me somehow. I'd swear right back today |=A0}:-p | | Since my expertise is Technical., you just keep giving us the best | designs possible for the best Installation/assembly possible. | | | And Phil; don't harass me any more over what you think I don't | understand, I am not dumb, didn't I spell it out with positive | assertion?, some of you are damn near insulting and inhospitable like in | here ... | some of you are cool, others perhaps just confused about my assertions. | Roy ~ E.E. Tech The NEC is not just about what is electrically safe. Many rules are about the _practices_ of electrical power installations with regard to making conditions that can stay safe under errant usage and maintenance conditions. Many of the rules are intended to prevent mistakes. An obvious example is the requirements for certain insulation colors on certain conductor types, such as white/gray for neutral, and green for ground. I'm sure you know as well as I do that electrons and magnetic fields don't give a damn whether the neutral wire is insulated with gray or blue or brown insulating material. But making sure an installation is unstandable when maintained is as much of what these rules are about as anything else. And sometimes it just does not make a lot of sense until you look at things in the context of what happens when someone else comes along to do maintenance or upgrades on the work you originally did. They need to be able to understand enough of it to be sure that mistakes cannot be made (such as connecting a hot wire with white color insulation to the neutral terminal of a new receptacle) unsafe. I don't always see those rules for what they are myself. So sometimes I have to push people to get an explanation. Sometimes no one really knows why a given "stupid" rule is there. There must be a reason. If after extensive questioning of many people, no reasonable explanation is found, submit a proposed change (to undo that rule) to the appropriate NEC committee and see what their rsponse is. They might include a reason for not changing it. Or they might change it. But your instance that 15 amp receptacles are not permitted on 20 amp circuits despite a clear and obvious NEC rule that allows it, is not earning you any credibility here. [ * also one that disallows it ] ~~~~~~~~~~~~~~~~~~~~~~~~~ Phil: I think you were exposed to one Rotgen too many back in the days., I don't have any instance left, but, you should switch to decaf anyway- =AEoy

Reply to
Roy Q.T.

I would agree with the interpretation of 210.21(B)(3)as applicable. The NEC language is a little different with regard to "outlets" and "receptacle". Although people often refer to a receptacle as an outlet, they are treated as two different things in the NEC.

Here's three definitions from the NEC: "Outlet. A point on the wiring system at which current is taken to supply utilization equipment."

"Receptacle. A receptacle is a contact device installed at the outlet for the connection of an attachment plug. A single receptacle is a single contact device with no other contact device on the same yoke. A multiple receptacle is two or more contact devices on the same yoke."

"Receptacle Outlet. An outlet where one or more receptacles are installed."

Ed

Reply to
ehsjr

Don't lose the concept in the minutae. The 20 amp T slot receptacle serves two purposes: it allows devices with NEMA 5-20 's to be plugged in, and it also identifies the receptacle as being on a 20 amp branch. Manufacturers have to follow a host of rules/standards/practices etc, and to get UL listing, nust use the correct plug on cord and plug connected devices they make.

The violation would occur if you wired a 20 amp receptacle on a 15 amp branch, regardless of what gets plugged in. As you noted in another post, 210.21(B) with a multiple receptacle (or receptacles) on the branch. A dedicated (meaning serving a single receptacle) 15 Amp circuit is ridiculous enough on its own without compounding it by makeing the receptacle

20 amps.

Ed

Reply to
ehsjr

On Fri, 17 Jun 2005 07:44:38 GMT ehsjr wrote: | snipped-for-privacy@ipal.net wrote: | |> |> That's 80 percent of the BRANCH CIRCUIT rating. 80 percent of 20 amps |> is 16 amps. So in theory, if I have multiple NEMA 5-15R receptacles on |> a 20 amp branch circuit, I could draw up to 16 amps from one outlet and |> not violate this rule. I would not worry about it in a technical sense |> with respect to the receptacle since I know it is rated to 20 amps. The |> plug in use might not be, but 20 amp plugs don't appear to be any more |> robust than 15 amp plugs; they just have a twisted neutral. |> |> So which rule would I be violating if in this case a single cord-and-plug |> connected appliance draw more than 12 amps? What rule requires equipment |> over 12 amps to use a NEMA 5-20P or larger? A UL listing requirement? |> | | Don't lose the concept in the minutae. The 20 amp T slot | receptacle serves two purposes: it allows devices with | NEMA 5-20 's to be plugged in, and it also identifies | the receptacle as being on a 20 amp branch. Manufacturers | have to follow a host of rules/standards/practices etc, | and to get UL listing, nust use the correct plug on | cord and plug connected devices they make. | | The violation would occur if you wired a 20 amp receptacle on | a 15 amp branch, regardless of what gets plugged in. As you | noted in another post, 210.21(B) with a multiple receptacle | (or receptacles) on the branch. A dedicated (meaning serving | a single receptacle) 15 Amp circuit is ridiculous enough on | its own without compounding it by makeing the receptacle | 20 amps.

I agree it is ridiculous (one 20 amp single outlet on a 15 amp circuit). Nevertheless, I see no NEC rule that prohibits it.

OTOH, what would you put on a 40 amp circuit? Not a NEMA X-30R I hope. Yeah, I know this is a bit different than 15 vs. 20.

Who wants to submit a rule change to the NEC committee on this?

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phil-news-nospam

| But your instance that 15 amp receptacles are not permitted on 20 amp | circuits despite a clear and obvious NEC rule that allows it, is not | earning you any credibility here. [ * also one that disallows it ] | ~~~~~~~~~~~~~~~~~~~~~~~~~ | Phil: I think you were exposed to one Rotgen too many back in the | days., I don't have any instance left, but, you should switch to decaf | anyway- ?oy

I was exposed to the text of the NEC. I suggest you get yourself exposed to it as well. Start with 210.21(B)(3). Read the 2nd line of the table.

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phil-news-nospam
050616 2113 - snipped-for-privacy@ipal.net posted:

So, is the sky going to fall if a 20 amp duplex receptacle is installed on a

15 amp branch circuit with other 15 amp duplex receptacles?
Reply to
indago

On Fri, 17 Jun 2005 15:54:09 GMT indago wrote: | 050616 2113 - snipped-for-privacy@ipal.net posted: | |> On Thu, 16 Jun 2005 20:53:38 GMT indago wrote: |> | 050616 0130 - Roy Q.T. posted: |> | |> |> NEC 210.21 [(B)(1)] ~ Receptacles: A single receptacle installed on an |> |> individual branch circuit shall have an ampere rating "not less" than |> |> that of the branch circuit. |> |> ?oy |> |> |> |> From: snipped-for-privacy@aol.com |> |> On 8 Jun 2005 04:21:48 GMT, snipped-for-privacy@ipal.net wrote: |> |> It could just be that I can't find the part of the code that says a 15 |> |> amp circuit cannot have a 20 amp receptacle |> |> Look at 210.21(B)(3) again. The top line says 15a circuits shall have |> |> receptacles "not over 15a" |> |> |> | |> | So, what if you put a 20 Amp duplex receptacle on a 15 Amp branch circuit? |> |> That is not permitted by NEC 210.21(B)(3). See table 210.21(B)(3). |> But this only applies to circuits with 2 or more outlets. A duplex |> receptacle is 2 outlets, so it applies. However, I see no rule that |> would prohibit this for a _single_ outlet circuit. | | So, is the sky going to fall if a 20 amp duplex receptacle is installed on a | 15 amp branch circuit with other 15 amp duplex receptacles?

Depends on your AHJ/inspector. If it was me, you'd get a red tag.

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phil-news-nospam

From: snipped-for-privacy@ipal.net On Fri, 17 Jun 2005 02:16:10 -0400 Roy Q.T. wrote: | But your instance that 15 amp receptacles are not permitted on 20 amp | circuits despite a clear and obvious NEC rule that allows it, is not | earning you any credibility here. [ * also one that disallows it ] |=A0=A0=A0=A0=A0=A0=A0~~~~~~~~~~~~~~~~~~~~~~~~~ | Phil: I think you were exposed to one Rotgen too many back in the | days., I don't have any instance left, but, you should switch to decaf | anyway- ?oy I was exposed to the text of the NEC. I suggest you get yourself exposed to it as well. Start with 210.21(B)(3). Read the 2nd line of the table.

-- Fuck That ! I've got it right., I am through with this topic, you are a bunch of Illogical hard heads .... =AE

Reply to
Roy Q.T.

One Last Thing, For Ed & Phil : What you are saying is, You can't install a 20A Receptacle on a 15A circuit, but, you can install a 15A receptacle ona 20A circuit is that what you are saying the NEC allows here ? Roy

From: snipped-for-privacy@bellatlantic.net (ehsjr) snipped-for-privacy@ipal.net wrote: That's 80 percent of the BRANCH CIRCUIT rating. 80 percent of 20 amps is

16 amps. So in theory, if I have multiple NEMA 5-15R receptacles on a 20 amp branch circuit, I could draw up to 16 amps from one outlet and not violate this rule. I would not worry about it in a technical sense with respect to the receptacle since I know it is rated to 20 amps. The plug in use might not be, but 20 amp plugs don't appear to be any more robust than 15 amp plugs; they just have a twisted neutral. So which rule would I be violating if in this case a single cord-and-plug connected appliance draw more than 12 amps? What rule requires equipment over 12 amps to use a NEMA 5-20P or larger? A UL listing requirement? Don't lose the concept in the minutae. The 20 amp T slot receptacle serves two purposes: it allows devices with NEMA 5-20 's to be plugged in, and it also identifies the receptacle as being on a 20 amp branch. Manufacturers have to follow a host of rules/standards/practices etc, and to get UL listing, nust use the correct plug on cord and plug connected devices they make. The violation would occur if you wired a 20 amp receptacle on a 15 amp branch, regardless of what gets plugged in. As you noted in another post, 210.21(B) with a multiple receptacle (or receptacles) on the branch. A dedicated (meaning serving a single receptacle) 15 Amp circuit is ridiculous enough on its own without compounding it by makeing the receptacle 20 amps. Ed
Reply to
Roy Q.T.

I am neither Ed nor Phil, but you have to be clear what is meant by "15A" and "20A". You have the slot configuration on the face (15A, NEMA 5-15R which is the ordinary outlet and 20A, NEMA 5-20R, has a T shaped slot which can accept either an ordinary 5-15P plug or a 20A 5-20P plug which has a horizontal pin) and how heavy-duty the metal in the device, whether it is rated to carry 15A or 20A through it. This leads to 3 possibilities:

15A rated device, 5-15R face; 20A rated device, 5-15R face; 20A rated device, 5-20R face.

(The fourth possibility shouldn't ever exist)

The first one may or may not exist legally. (like I mentioned, I have a suspect).

The first two can be connected to a 15A circuit fine. The second and third are fine for a 20A circuit. Hooking the first to a 20A circuit could cook it just like connecting #14 wire to a 20A breaker. There is no reason for a device with a 5-20R face to be on a 15A circuit. Something with a 5-20P plug (rare) has a good reason for doing so and would overload a 15A circuit.

Reply to
Michael Moroney

| One Last Thing, For Ed & Phil : What you are saying is, You can't | install a 20A Receptacle on a 15A circuit, but, you can install a 15A | receptacle ona 20A circuit is that what you are saying the NEC allows | here ? Roy

A 15 amp circuit with exactly one outlet: NEMA 5-15R or NEMA 5-20R A 20 amp circuit with exactly one outlet: NEMA 5-20R only A 15 amp circuit with multiple outlets: NEMA 5-15R's only A 20 amp circuit with multiple outlets: NEMA 5-15R's and NEMA 5-20R's

Change "5-" to "6-" for 240 volt circuits, or to "14-" for 120/240 volt circuits. The rules are not specific to a particular voltage.

It's the 5-20R on a 15 amp circuit with one outlet that most people believe is a bad idea. But 210.21(B)(1) sure appears to permit it. I sure hope there is some other code that I have overlooked that would prohibit this, but that is the part where such code should be.

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phil-news-nospam

| From: snipped-for-privacy@ipal.net | On Fri, 17 Jun 2005 02:16:10 -0400 Roy Q.T. wrote: | | But your instance that 15 amp receptacles are not permitted on 20 amp | | circuits despite a clear and obvious NEC rule that allows it, is not | | earning you any credibility here. [ * also one that disallows it ] | |???????~~~~~~~~~~~~~~~~~~~~~~~~~ | | Phil: I think you were exposed to one Rotgen too many back in the | | days., I don't have any instance left, but, you should switch to decaf | | anyway- ?oy | I was exposed to the text of the NEC. I suggest you get yourself exposed | to it as well. Start with 210.21(B)(3). Read the 2nd line of the table. | -- | Fuck That ! I've got it right., | I am through with this topic, you are a bunch of Illogical hard heads | ....

I think I'll submit the rule change to make as Roy _thinks_ it is, and dedicate it in his honor. Aside anything else, his boneheadedness over this piece of code is probably getting it into more minds about its silliness. I sure wish Roy was right on this one, but so far no one has shown any code citation to support it.

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phil-news-nospam

Okay., I never said a 20R or any other type but a regular duplex or single receptacle in my response to this post nor did i include TSlot or

220vac outlets., so go ahead for that change: Use of 15Amp & 20Amp receptacles on a 15Amp 125AC circuit is allowed., use of a 15A receptacle on a 20Amp circuit is not permted.....It's really not much difference but, that is what i was taught. Phil you Flatter me };-) Have a nice weekend. Roy

From: snipped-for-privacy@ipal.net On Fri, 17 Jun 2005 14:07:48 -0400 Roy Q.T. wrote: | From: snipped-for-privacy@ipal.net | On Fri, 17 Jun 2005 02:16:10 -0400 Roy Q.T. wrote: | | But your instance that 15 amp receptacles are not permitted on 20 amp | | circuits despite a clear and obvious NEC rule that allows it, is not | | earning you any credibility here. [ * also one that disallows it ] |=A0|???????~~~~~~~~~~~~~~~~~~~~~~~~~ | | Phil: I think you were exposed to one Rotgen too many back in the | | days., I don't have any instance left, but, you should switch to decaf | | anyway- ?oy | I was exposed to the text of the NEC. I suggest you get yourself exposed | to it as well. Start with 210.21(B)(3). Read the 2nd line of the table. |=A0-- | Fuck That ! I've got it right., | I am through with this topic, you are a bunch of Illogical hard heads |=A0.... I think I'll submit the rule change to make as Roy _thinks_ it is, and dedicate it in his honor. Aside anything else, his boneheadedness over this piece of code is probably getting it into more minds about its silliness. I sure wish Roy was right on this one, but so far no one has shown any code citation to support it.

Reply to
Roy Q.T.
050617 1548 - Michael Moroney posted:

Are you saying that the 15 amp circuit breaker would not trip out in this case?

Reply to
indago

A situation encountered in the field does not necessarily need to have a specific prohibition in the NEC in order for it to be rejected by the AHJ. See 110.3(A)(7). 110.3 (A) requires that the inspector evaluate the installation for the items listed. Item (7) does not prohibit a 20 amp receptacle on a 15 amp branch, per se, but does prohibit it, de facto .

Ed

Reply to
ehsjr

Yes. Ed

Reply to
ehsjr

From: snipped-for-privacy@bellatlantic.net (ehsjr) Roy Q.T. wrote: One Last Thing, For Ed & Phil : What you are saying is, You can't install a 20A Receptacle on a 15A circuit, but, you can install a 15A receptacle ona 20A circuit is that what you are saying the NEC allows here ? Roy

Yes. Ed

Then : You are right per se, and quite wrong de facto };-) Okay', and I understand this very well , but I just hate it when posters assume that the cat has 5 legs and start slinging crap around, like we have time to toss the ball around in here. Roy

Reply to
Roy Q.T.

On Sat, 18 Jun 2005 04:58:49 GMT indago wrote: | 050617 1548 - Michael Moroney posted: | |> snipped-for-privacy@webtv.net (Roy Q.T.) writes: |> |>> One Last Thing, For Ed & Phil : What you are saying is, You can't |>> install a 20A Receptacle on a 15A circuit, but, you can install a 15A |>> receptacle ona 20A circuit is that what you are saying the NEC allows |>> here ? Roy |> |> I am neither Ed nor Phil, but you have to be clear what is meant by "15A" |> and "20A". You have the slot configuration on the face (15A, NEMA 5-15R |> which is the ordinary outlet and 20A, NEMA 5-20R, has a T shaped slot |> which can accept either an ordinary 5-15P plug or a 20A 5-20P plug which |> has a horizontal pin) and how heavy-duty the metal in the device, whether |> it is rated to carry 15A or 20A through it. This leads to 3 possibilities: |> |> 15A rated device, 5-15R face; |> 20A rated device, 5-15R face; |> 20A rated device, 5-20R face. |> |> (The fourth possibility shouldn't ever exist) |> |> The first one may or may not exist legally. (like I mentioned, I have |> a suspect). |> |> The first two can be connected to a 15A circuit fine. The second and |> third are fine for a 20A circuit. Hooking the first to a 20A circuit |> could cook it just like connecting #14 wire to a 20A breaker. There |> is no reason for a device with a 5-20R face to be on a 15A circuit. |> Something with a 5-20P plug (rare) has a good reason for doing so and |> would overload a 15A circuit. | | Are you saying that the 15 amp circuit breaker would not trip out in this | case?

It should trip it. This can be why 20 amp outlets are not permitted on multiple-outlet circuits with 15 amp breakers. They do not seem to be prohibited on single-outlet circuits. Maybe the distinction here is that on a single-outlet circuit, when it trips, it won't knock out other stuff.

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