electric outlet for window AC question

|> I've never actually seen such a patch job, and certainly would never |> recommend it. | | Well, I saw on in a house that was "modern" in 1958 but had a fuse box. It | did have the "heavy" circuits for the stove and dryer, however.

So what did they do when clothes needed to be dried? Wait until night?

| | Folks put in these BIG window units because they don't have the money to put | in Central Air and install an entirely new service. I never "opened up" | such an installation, but dryer circuits are often/usually just 30 amps so | #10 romex would be protected. It may not be "code" but it's not asking | for trouble either.

Aside from blowing the fuse when someone runs the A/C and dryer at the same time. Today's NEC tries to avoid this, knowing full well that in the past, people faced with blowing fuses would do things to defeat the protection.

|>But in DIY type forums, I've seen a number of people |> ask how to do it (IMHO, that would not be a project for someone with |> so little experience in wiring they would have to ask how to). | | True. But even if you are taking short cuts it doesn't mean you don't want | to be a safe as you can manage without spending an arm and a leg. | | It seems to me that the folks who create the NEC sometimes DO worry about | economy and DO reason that it's better to have GOOD safety at reasonable | cost over GREAT safety at a cost that encourages folks to just jury rig. But | when they mandated the "arc detection breaker" I wondered.

They only mandated it for new construction or major remodeling. Replacing an outlet would not generally require it. IMHO, it would also not be required just to extend the circuit.

| I notice that the "dryer and stove" outlets with only three wires | (chassis/neutral are bonded in the appliance) don't make any effort to | connect neutral before hot. Of course, for the last 30 years dryers are | completely "off" until you push the start button and the only 120 volt loads | in the stove are the lamp and the timer so ...)

I understand that the motor is 120 volts, too, so they can use the same exact motor for the gas models.

|>But it has shaken up |> some dust that probably shouldn't be where it has settled long ago. I am |> considering making an information web page on the subject "15 vs 20 amps". | | Fine. Put in a "questions and comments" BB if you can.

I've been thinking of setting up a whole "code comments" forum board. It would be oriented to issues about complying with, or changing, the electrical code, and targeted to electricians, engineers, and others with an interest. It wouldn't be a DIY forum.

On Tue, 21 Jun 2005 14:48:15 GMT HorneTD wrote: | ehsjr wrote: |> Roy Q.T. wrote: |> |>> I don't think so Ed; There are a variety of them and i read recently |>> that the specs for a 15 & 20 amp receptacles are different, they might |>> seem the same but the metals employed are tempered differently and their |>> capacity is limited to there rating. |>>

|>> Believe me I am not making this up: A 15 Amp circuit will trip if it |>> goes over the rated current with both 15 & 20A with no ill effects on |>> them, but, the study specifically mentioned that 15A units on a 20A |>> circuit can suffer as any underrated equipment used on the supply or |>> convenience outlet circuitry., I do not think much of it either and have |>> bought random duplex receptacles without minding there current ratings |>> and am just a little self conscious about it now since this came up on |>> this thread.,Given my past observations I am just reiterating the |>> concept of careful circuit component matching to myself };-) |>> ?oy |>>

|> |> Thanks, Roy! |> |> I would love to read the article if you can find it. |> My information came from UL and is dated 1991 - so |> if there is something new that superceeds it, I am |> eager to learn. |> |> Ed | | The UL standard is unchanged. Both 15 and 20 ampere receptacles must be | capable of carrying 20 amperes continuous without damage.

So basically both are true 20 amp receptacles, with one of them not having the mating hole for 20 amp plugs so it can be used on 15 amp circuits.

Maybe it's time for the NEC to stop allowing 15 amp circuits in new construction for other than single outlet dedicated uses for what few appliances might need 15 amp OCP. Just have everything new go with

20 amps and simplify things.

Why not?

Roy Q.T. wrote: I don't think so .....

ET AL

Phil Wrote: Maybe it's time for the NEC to stop allowing 15 amp circuits in new construction for other than single outlet dedicated uses for what few appliances might need 15 amp OCP. Just have everything new go with

20 amps and simplify things.

Thanks, Tom!

|> I've been thinking of setting up a whole "code comments" forum board. |> It would be oriented to issues about complying with, or changing, the |> electrical code, and targeted to electricians, engineers, and others |> with an interest. It wouldn't be a DIY forum. | | Why not?

There are already a few DIY forums around.

| Phil Wrote: Maybe it's time for the NEC to stop allowing 15 amp circuits | in new construction for other than single outlet dedicated uses for what | few appliances might need 15 amp OCP. Just have everything new go with | 20 amps and simplify things. | -- | | Finally someone made some sense out of this post., it covers my point | exactly and the status quo. Thanks Phil ! | Roy

I don't know that it is status quo. I still see new home construction with a mix of 15 amp and 20 amp circuits. 14 AWG wire is cheaper than

12 AWG wire, so it seems home builders want to put in 15 amp circuits everywhere the code does not require more amps so they can use that cheaper cable. I do see 20 amp receptacles in places where the code only requires 20 amp circuits, so this much certainly is status quo. My new house construction plan is to go with 12 AWG everywhere except where a larger circuit is needed.

Not only is the cable cheaper (but not as much as you might think) but it a heck of a LOT easier to install.

From the view of having safe and cost effective power distribution in the home, "they" (the government and the NEC) should start to "encourage" use installation of 240 volt (no neutral but with ground) outlets and also require that all appliances that draw from than, say, 1 kW have at least 25% of their distribution (US) be for 240 volt supply. Dish and clothes washers that attempt to HEAT the water would work MUCH better at 240 volts; microwave ovens would also work better.

A #14 circuit with a 2 pole 15 amp breaker would be as "safe" (for most purposes) as the 120 volt circuit but could supply twice the power.

|> I don't know that it is status quo. I still see new home construction |> with a mix of 15 amp and 20 amp circuits. 14 AWG wire is cheaper than |> 12 AWG wire, so it seems home builders want to put in 15 amp circuits |> everywhere the code does not require more amps so they can use that |> cheaper cable. | | Not only is the cable cheaper (but not as much as you might think) but it a | heck of a LOT easier to install. | | From the view of having safe and cost effective power distribution in the | home, "they" (the government and the NEC) should start to "encourage" use | installation of 240 volt (no neutral but with ground) outlets and also | require that all appliances that draw from than, say, 1 kW have at least 25% | of their distribution (US) be for 240 volt supply. Dish and clothes | washers that attempt to HEAT the water would work MUCH better at 240 volts; | microwave ovens would also work better. | | A #14 circuit with a 2 pole 15 amp breaker would be as "safe" (for most | purposes) as the 120 volt circuit but could supply twice the power.

I would definitely go along with this idea. Currently the NEC requires the opposite in homes at the 1440 watt level ... e.g. if less than 1440 watts, 120 volts must be used. That's a rule I'd like to see dropped or even inverted as in your recomendation.

Many of these products are already available for 240 volts, and even work on 60 Hz ... just not in the USA (though in some, some rewiring can make it work on 240 volts again).

I'd also like to see use of the neutral discouraged on appliances that now do use 120/240 volt circuits (e.g. clothes dryers and ranges). Most of the world knows that power supplies for electronics really can operate on

240 volts AC coming in. Even the light bulbs inside these appliances are these days using bi-pin type mountings, eliminating the risk of contact with an electrically hot shell base for a bulb.

From: snipped-for-privacy@ipal.net On Wed, 22 Jun 2005 04:23:53 -0400 John Gilmer wrote: I don't know that it is status quo. I still see new home construction with a mix of 15 amp and 20 amp circuits. 14 AWG wire is cheaper than 12 AWG wire, so it seems home builders want to put in 15 amp circuits everywhere the code does not require more amps so they can use that cheaper cable. | | Not only is the cable cheaper (but not as much as you might think) but it a | heck of a LOT easier to install. | | From the view of having safe and cost effective power distribution in the | home, "they" (the government and the NEC) should start to "encourage" use | installation of 240 volt (no neutral but with ground) outlets and also | require that all appliances that draw from than, say,

1 kW have at least 25% | of their distribution (US) be for 240 volt supply. =A0 Dish and clothes | washers that attempt to HEAT the water would work MUCH better at 240 volts; | microwave ovens would also work better. | | A #14 circuit with a 2 pole 15 amp breaker would be as "safe" (for most | purposes) as the 120 volt circuit but could supply twice the power. I would definitely go along with this idea. Currently the NEC requires the opposite in homes at the 1440 watt level ... e.g. if less than 1440 watts, 120 volts must be used. That's a rule I'd like to see dropped or even inverted as in your recommendation. Many of these products are already available for 240 volts, and even work on 60 Hz ... just not in the USA (though in some, some rewiring can make it work on 240 volts again). I'd also like to see use of the neutral discouraged on appliances that now do use 120/240 volt circuits (e.g. clothes dryers and ranges). Most of the world knows that power supplies for electronics really can operate on 240 volts AC coming in. Even the light bulbs inside these appliances are these days using bi-pin type mountings, eliminating the risk of contact with an electrically hot shell base for a bulb.

Roy & Phil

May I ask why you would want to raise the cost of constructing housing without any gain in actual utility of the installed system.

You are advocating the installation of 2400 VA circuits to serve distributed loads that are less than 1000 VA. The code's present requirement is the provision of three volt/amperes per square foot of finished space for general lighting and receptacle circuits. There is no evidence that this is in fact inadequate. If your resources and preferences permit you to build to a higher standard I have no problem with that. But when you try to impose a gold plate standard on the construction of the entirety of the nations future housing stock and thus insure that more people will never be able to own their own home I have to believe you have something to gain by pricing more families out of the housing market. Are you heavily invested in rental property? If not why do you want to limit access to housing by making it less affordable without any improvement in actual utility or safety to justify the cost increase? Were is the circuit loading that would justify the cost of twenty ampere circuits to power clock radios, table lamps and cell phone chargers. Why not standardize on one hundred ampere circuits with all outlets protected by individual outlet breakers!

100Amps all around ? shucks they only suggested use of 240vac where it coud be used.

I never said I was against 15Amp circuits, and., Why exagerate if your goal is to limit costs to make housing more affordable? You are peering over the Riff Tom step back a bit before you fall };-)

I only advoate for stronger circuits where they are most likely to be abused or over loaded in the immediate future., not that we over due the individual outlet capacity for the average dwelling place....

Where did you get that idea from ?

We can make cheaper houses, like I heard of one house with one receptacle in the living room and each bedroom, no outlet in the bathroom and perhaps two in the kitchen., but then those buyers are the ones coming to us with how much to wire up more receptacles in their houses., because the cheap developers didn't have any sense to wire down more convenience outlets };-)

I'm game, minimize the outlet circuitry in all new dwellings and together we can open a new $pecialzed $ervice depot :-) Roy

Hard to believe but apparently true. A single outlet just has to have a higher rating than the branch circuit. Not only can you put a 20 amp single receptacle on a 15 amp circuit you can put a 30 amp, 100 amp ....

This appears to have been in effect at least back into the 1980s.

One way to see check the reasoning behind a code item is to look for proposed changes and see how the code making panel responds. There were no proposed changes to this rule as far back as 1983 (1996 and 1993 are unknown). This rule was invisible?

Bud--

050621 1518 - snipped-for-privacy@ipal.net posted:

Here is a place on the web with a forum:

050623 1204 - HorneTD posted:

Plus the fact that a lamp cord has a tough enough time tripping out a 15 amp breaker, let alone raising the ante to 20 amps. I heard a rumor that an Ohio town is demanding that general outlets in living rooms, bedrooms, and such be on 15 amp circuits.

On Thu, 23 Jun 2005 16:07:59 -0500 Bud wrote: | HorneTD wrote: | |> |> |> Phill has a point. 210.21 (B) (3) would not appear to apply to branch |> circuits that only have one outlet. I strongly suspect that was not |> what the code making panel intended but the way 210.21 (B)(1) reads now |> you could put a twenty ampere receptacle as the only outlet on a fifteen |> ampere circuit. | | | Hard to believe but apparently true. A single outlet just has to have a | higher rating than the branch circuit. Not only can you put a 20 amp | single receptacle on a 15 amp circuit you can put a 30 amp, 100 amp .... | | This appears to have been in effect at least back into the 1980s. | | One way to see check the reasoning behind a code item is to look for | proposed changes and see how the code making panel responds. There were | no proposed changes to this rule as far back as 1983 (1996 and 1993 are | unknown). This rule was invisible?

There may have been _other_ rules in place that negated the bad effects of this rule. Note that 210.21(B)(1) allows either an equal rating or a higher rating on the single outlet. Another rule could prohibit the higher rating, resulting in only allowing an equal rating when both rules are in effect together. The other rule may have existed in the past and then was removed.

HOWEVER, the issue is not as simple as that. What if the appliance that needs a dedicated circuit requires 25 amp overcurrent protection, where

20 amps is too low (will trip) and 30 amps is too high (could allow a long term overheating issue). You can put in a 25 amp breaker easily enough. But what size of receptacle do you use? A 20 amp one is too small. A 30 amp would would be safe in that it should not burn up with 25 amps used through it. What 210.21(B)(1) does is allow use of the 30 amp outlet.

What I think the rule should be change to is that for a given circuit rating, the only outlet allowed is one with a _configuration_ equal to the circuit rating for circuits matching a configuration, or the next higher configuration where a matching one is not standardized. Thus:

circuit outlet

10 amp 15 amp (I think 10 amp is still allowed on dedicated circuits) 15 amp 15 amp 20 amp 20 amp (maybe use 20-amp only outlet) 25 amp 30 amp 30 amp 30 amp 35 amp 50 amp 40 amp 50 amp 45 amp 50 amp 50 amp 50 amp 55 amp 60 amp 60 amp 60 amp etc

Such a code change should reference NEMA standards for outlet configuration. Then a 30 amp outlet would be allowed on a 25 amp circuit, but a 50 amp outlet would not be allowed. I think we all (even Roy) would agree this is the way it should be.

One thing I think the code needs to do is distiguish with better terminology the difference between the current capacity rating of a device, and its configuration with respect to the standard plugs it will accept. NEMA X-15R devices do (now days) have a current carrying rating of 20 amps. As long as appliances plugged in are unlikely to create overcurrent situations of more than their own cord-and-plug rating without exceeding the 20 amp trip current, things are safe allowing receptacles on 20 amp multi-outlet circuits that accept 15 amp plugs. The 20 amp configuration accepts 15 amp plugs, so there is no new hazard in this regard by installing a receptacle that refuses to accept 20 amp plugs. You can get 20 amp receptacles that do refuse 15 amp plugs, and that can be useful on single outlet circuits.

|> I've been thinking of setting up a whole "code comments" forum board. |> It would be oriented to issues about complying with, or changing, the |> electrical code, and targeted to electricians, engineers, and others |> with an interest. It wouldn't be a DIY forum. | | Here is a place on the web with a forum: | |

I might have to try that one out with this 15 vs. 20 amp outlet issue and see what they say. I had seen the Mike Holt site before, but had not found a forum there. Thanks for the link.

|> Maybe it's time for the NEC to stop allowing 15 amp circuits in new |> construction for other than single outlet dedicated uses for what few |> appliances might need 15 amp OCP. Just have everything new go with |> 20 amps and simplify things. |> | | | Roy & Phil | | May I ask why you would want to raise the cost of constructing housing | without any gain in actual utility of the installed system.

Because it will eliminate issues with respect to the confusion about compatibility between 15 amp and 20 amp circuits, receptacles, outlets, plugs, and appliances.

| You are advocating the installation of 2400 VA circuits to serve | distributed loads that are less than 1000 VA. The code's present | requirement is the provision of three volt/amperes per square foot of | finished space for general lighting and receptacle circuits. There is | no evidence that this is in fact inadequate. If your resources and | preferences permit you to build to a higher standard I have no problem | with that. But when you try to impose a gold plate standard on the | construction of the entirety of the nations future housing stock and | thus insure that more people will never be able to own their own home I | have to believe you have something to gain by pricing more families out | of the housing market. Are you heavily invested in rental property? If | not why do you want to limit access to housing by making it less | affordable without any improvement in actual utility or safety to | justify the cost increase? Were is the circuit loading that would | justify the cost of twenty ampere circuits to power clock radios, table | lamps and cell phone chargers. Why not standardize on one hundred | ampere circuits with all outlets protected by individual outlet breakers!

Who said the loads would be less than 1000 VA ... in the future? Using

20 amp circuits can, for areas of the home away from where 20 amp circuits are now already required, could just put more square footage on the same circuits. You'd have fewer runs back to the panel, and fewer breakers. If the area served by a circuit is 33% larger, and the circuit is 33% larger, it's the same loading density. But now you'll have a more uniform wiring configuration leading to less confusion.

| Plus the fact that a lamp cord has a tough enough time tripping out a 15 amp | breaker, let alone raising the ante to 20 amps. I heard a rumor that an | Ohio town is demanding that general outlets in living rooms, bedrooms, and | such be on 15 amp circuits.

What town is that?