So do I need a 20 amp outlet?

[Troy Turner]

So I was running some 14-2 for an outlet for my clock radio. My 15amp socket had the push-hole in the back, but it only fit 14 ga wire. So I got to looking at the rest of my outlets. Yup, 15ga outlets everywhere with 12-2 and they're all on 20amp breakers.

I haven't looked at the specs yet, but will when I get home. I guess if they're rated for 15 amps, then I'm good.

So the question is, for my T/S and bandsaw, they're both older Craftsman belt drives. Am I losing anything by only having them on 15amp outlets? My shop was my first major electrical doing many years ago...so it's possibly I didn't do ALL my homework. I'm going to put a couple more outlets up, but if I need to go to a 20amp outlet, I'll just replace all of them. There's only about 10 total, even with the new ones.

Thanks for the advice...

[Rick Moyer]

I'm not an electrician so this is only my opinion: You need to know what the max amp draw is on whatever you plug into those outlets. 20amp breaker is designed to protect the wiring so 12-2 is good there, but the outlet should match as well. That being said, if you don't draw anywhere near 15 amps from the item plugged into those outlets YOU'LL likely be fine. But what if SOMEONE ELSE plugs a higher amp tool into the outlet, not realizing the outlet is only rated for 15a? I would replace all of the outlets to correctly match the breaker/wire circuit. That would be the best approach.

[Kent A Bathurst]

Sorry, but I have to answer a question you did not ask. If you are running 14ga wire, you are limited to a 15a breaker, to the best of my knowledge. The reason is that with a 20a breaker, you can pull more power than the wire can handle, and you don't want that happening. The wire becomes a fusible link.........:eek:

The existing circuits....I'm not too sure about those, but it seems to me there might a problem there also....a 20a breaker, and 12ga wire which is correct for 20a, but only 15a receptacles....the system can deliver more amps than the receptacle can handle, if you were to plug in a tool that draws >15a.

You can "undersize" in the other direction....meaning start with 20a at the receptacle, then to to 15a wire and 15a breaker. Or 20a recep, 12 ga wire, and 15a breaker.

I am not an electrician, but I got dope-slapped for a similar situation for 220v on a forum....and it stuck in my memory cells. So - I always run 12 ga wire for 110v circuits and 10 ga wire for 220v circuit.........even if I don't need it. I do it for future expansion, and upgrade the breaker[s] and recept[s] as needed. I overspend on the wire, but replacing the wire is the biggest PITA in the circuit.

[Lee Schierer]

Generally devices that require more than 15 amps generally have 20 amp plugs and they won't plug into a 15 amp outlet. A 20 amp breaker may have multiple 15 amp outlets on it so the wire is still protecting the circuit.

[Troy Turner]

Going to double check the ratings on the motors when I get home. Was trying to get to the hardware store and give me something to do tonight, but I guess I can wait another day. Yeah, all my plugs are regular plugs. No sideways prong on any of them.

[Dan Hintz]

Going to double check the ratings on the motors when I get home. Was trying to get to the hardware store and give me something to do tonight, but I guess I can wait another day. Yeah, all my plugs are regular plugs. No sideways prong on any of them.
As long as the 14 gauge wire is connected to a 15A breaker, you can put 20A-capable sockets on the line. As Kent said, matching the wire to the breaker is the most crucial part of the equation.

[Ron Natalie]

As long as the 14 gauge wire is connected to a 15A breaker, you can put 20A-capable sockets on the line. As Kent said, matching the wire to the breaker is the most crucial part of the equation.

INCORRECT. The National Electrical Code in article 210.21(B) *FORBIDS* this. You may not put a 20A receptacle on a 15A circuit PERIOD.

You can however put multiple (even a single duplex-style counts) 15A receptacles on a 12guage/20A-breaker circuit.

It's rare to see a portable tool that has other than a 15A plug.
For stationary tools, the easy fix is to often convert the circuit to 240V. 15A@240 gives you more power than 15A@120.

[Kent A Bathurst]

That's the bit I wasn't sure about, Ron....thnx.

[Dan Hintz]

INCORRECT. The National Electrical Code in article 210.21(B) *FORBIDS* this. You may not put a 20A receptacle on a 15A circuit PERIOD.
NEC article 210.21(B) states:

A single receptacle on an individual branch circuit can have a rating only equal to or larger than the rating of the individual branch circuit it is on except when installed in accordance with Section 430.81(C).
The mentioned section deals with motor controllers, but the verbiage clearly states the socket can be larger than the circuit capacity. Now, if there is more than one socket on the circuit, then you have to limit to 15A sockets.

[Mike Cutler]

Probably not.
Are they fitted with the OEM plugs? and do they fit in your existing receptacles? If the answer to both questions is yes, you're fine. Sears and UL did the work for you.

[Troy Turner]

Sounds like I'm on track with where ya'll are going with this. I have three lights and my clock radio on the same leg. It's 14ga w/one 15amp outlet.

The rest of my outlets (5) are running off 20a breakers and ran with 12ga wire and they have 15a sockets so I "pass" code.

Looked at my motors: T/S is a 1hp pulling 14amps. B/S is only 1/2 a horse and pulls 7.7. So I don't see a need in swapping all the sockets over.

Thanks for all the advice and future reference if I have to run anymore!!!

[Anthony Whitesell]

Question. Given a 20A breaker in the panel and 12g wire to a single duplex outlet, can a "15A" duplex socket supply 10A from each outlet without burning out, melting down, causing a fire, or some other catastropy?

[John Coloccia]

Ron is 100% correct. You cannot connect a 20A outlet on a 15A circuit. Dan, what you're quoting only applies to single receptacles. I suspect most of us use TWO receptacles per outlet. The fact that they're connected in a plastic package is irrelevant. I also vaguely seem to recall a section that calls out a table and specifically prohibits this even for single receptacles, but I could be wrong there. I don't have a NEC anymore.

15A receptacles, at least in the US (don't know what other countries do) have 20A "pass through", i.e. they won't melt down at 20A, but they DO prevent a 20A plug from being plugged in. On a 20A circuit, it is perfectly safe and acceptable to use 15A receptacles, though I seem to recall that you're required to have multiple receptacles to use a 15A on a 20A circuit (i.e. a normal duplex plug).

If you put a 20A receptacle on a 15A circuit, you may well have a device that draws normally draws 16A or 17A. This will put the circuit in an overload condition that can last for HOURS until something heats up enough to trip. It's not the kind of situation you want to have occurring by design.

That's the reasoning.

[shane lyall]

You want the weak link to be your breaker. A 15a outlet on 12 wire and a 20a breaker make the outlet the weak spot. Code in my county states 14g wire on 15a breaker. 12g on a 20a and outlet rating to match breaker size.

Someone mentioned 220 giving you more power. It will, sort of. The same amount of work done at 15 amps 220 volts would require 30 amps at 110. A popular misconception about 220 is it pulls more amps with the same load. Actually the 110 pulls more. My jointer for example is dual voltage 3hp and pulls 22 amps at 110 volts. It pulls 11 wired for 220 volts. When voltage goes up current goes down no matter the voltage.

[John Coloccia]

In order to get UL listed, 15A receptacles must be able to pass 20A. Said another way, 15A and 20A receptacles are essentially the same with the only real change being the faceplate to accept the 20A plug. I actually wouldn't be surprised to find that from the same manufacturer they are actually identical except for the faceplate.

The NEC allows 15A receptacles on a 20A circuit as long as there is more than one receptacle, and one duplex receptacle counts.

[shane lyall]

In order to get UL listed, 15A receptacles must be able to pass 20A. Said another way, 15A and 20A receptacles are essentially the same with the only real change being the faceplate to accept the 20A plug.


I learn something new every day! I've been licensed as an electrician in Virginia for almost 21 years now and didn't know this. Thanks John for the info. As far as code, each county may add to NEC but not take away. In my county it isn't allowed but one county over it is. Call your building department to make sure.

[Van Huskey]

First, John has it 100% correct.

RE 15 amp duplex receptacles, this is the most often ask question on electrical forums "can I use 15 amp receptacles on a 20 amp (12-2) circuit". John explains the entire thing but the key is the NEC considers each half of a duplex receptacle to be a device, thus it satisfies the requirement of more than one device in this case.

Shane, are you saying in your county a one must use 20 amp duplex receptacles on a 20 amp breaker/12-2 circuit? If so I would guess one sees a LOT of 15 amp circuits if the price of true 20 amp duplex outlets are the same there as I am used to.

My rule of thumb is to try never to read the NEC, unless you do it every day you will get caught in endless loops of contradictory sections trying to figure out which one actually applies. If you have a question either ask a electrician that does THAT type of work daily or call the inspector that will actually inspect the work.

PS I don't remember if anyone every addressed the back sticking issue. Back sticking (pokin' the wires in the rear of an outlet) is poor form! An electrician worth his salt would never back stick but thats another issue. A 15amp duplex outlet back sticking holes will accept a maximum 14 gauge wire, the receptacle is NOT rated to 20 amps if back stuck. In order to wire a receptacle on a 20 amp circuit (12-2 wire) you have to terminate with the screws. 15 amp breaker, 14-2 wire and back sticking meets NEC but, well I told you what I think of it.

[Dan Hintz]

.......


Nevermind... it seems the specifics are getting lost in the forest.

[Ron Natalie]

NEC article 210.21(B) states:

The mentioned section deals with motor controllers, but the verbiage clearly states the socket can be larger than the circuit capacity. Now, if there is more than one socket on the circuit, then you have to limit to 15A sockets.

No it doesn't say that. The motor exemption only applies to 1/3 HP or less motors on dedicated single receptacles. I think it's a reach to apply this to the poster's issue.
The general rules are as I stated. You can not put a 20A receptacle on a 15A circuit.

[Van Huskey]

"So the question is, for my T/S and bandsaw, they're both older Craftsman belt drives. Am I losing anything by only having them on 15amp outlets? My shop was my first major electrical doing many years ago...so it's possibly I didn't do ALL my homework. I'm going to put a couple more outlets up, but if I need to go to a 20amp outlet, I'll just replace all of them. There's only about 10 total, even with the new ones. "

Dan is right at least in as much as I don't the the OPs question was answered. If your tools will physically plug into a 15 amp receptacle (and they still have their orginal plugs on them) then you do not need 20 amp receptacles. 20 amp plugs have one blade that looks like a T instead of an I (the right one when looking at the plug, like you were going to plug it into your eyes and the ground blade underneath).

Although I am sure they probably exist I have yet to see a handheld power 120v tool with a 20 amp plug and can't remember ever seeing a stationary tool that was wired with a 120V 20 amp plug from the factory. There are some machines that require a 20 amp circuit/plug when wired for 120V but usually they come without a plug since most of them are dual voltage.

The point of the different plugs, receptacles and wiring codes is to ensure that if the plug fits it is fine to plug it in and use it.

If the plug fits, you are fine to quit (worrying and get to working) and If the plug doesn't fit you must refit (a new circuit). With apologies to the late Johnny Cochran.

[Anthony Whitesell]

I think this had been covered. "15A" outlets can actually carry 20 amps, but are meant for devices that only draw 15A each. "20A" outlets are meant for areas where one piece of equipment will draw 15-20A.

Jet makes/made a belt sander with a 20A plug pre-installed. I saw it around 2001-2002. I'm not sure if they still make it or if they do, if the supply it with a plug. I would suspect if the motor was not convertable to 240V, then it comes with the plug.

[Ron Natalie]

Yes, there is special dispensation on 15 and 20. Usually you have to match the receptacle to the circuit rating. A L5-30R must be on a 30A circuit.

There are two exceptions. Multiple 15's can go on a 20A rated circuit. Second, 20A receptacles can be designed to accept 15A plugs.

[Kent A Bathurst]

My head is spinning...........which is why I always "overbuild".........so I can't do anything wrong other than throw a few wasted bucks into some components. And - it's not like I rewire a house - I had an electrician put a 100a sub-panel in the basement for the shop, and I just drag electrons out of there for the shop stuff.

[Van Huskey]

My head is spinning...........which is why I always "overbuild".........so I can't do anything wrong other than throw a few wasted bucks into some components. And - it's not like I rewire a house - I had an electrician put a 100a sub-panel in the basement for the shop, and I just drag electrons out of there for the shop stuff.

I wired the most recent house we built just for the experience. Since I was the GC and we did 60% of the work on the house I spent a lot of time in houses being built in the neighborhood just seeing how the paid "trades" accomplished certain things. What I learned about the electrical side was I used a decent amount of extra material doing things I KNEW were OK instead of cutting corners that I didn't know was 100% OK. I got a little scared when the inspector ask me who did my electrical, when I said me he said it is the neatest job he had seen in 20 years. It wasn't neat because I am a neat freak it was neat so I could easily keep up with what I was doing!

[Joseph Tarantino]

So I was running some 14-2 for an outlet for my clock radio. My 15amp socket had the push-hole in the back, but it only fit 14 ga wire. So I got to looking at the rest of my outlets. Yup, 15ga outlets everywhere with 12-2 and they're all on 20amp breakers.

I haven't looked at the specs yet, but will when I get home. I guess if they're rated for 15 amps, then I'm good.

So the question is, for my T/S and bandsaw, they're both older Craftsman belt drives. Am I losing anything by only having them on 15amp outlets? My shop was my first major electrical doing many years ago...so it's possibly I didn't do ALL my homework. I'm going to put a couple more outlets up, but if I need to go to a 20amp outlet, I'll just replace all of them. There's only about 10 total, even with the new ones.

Thanks for the advice...

15A outlets routinely handle the amperage surge for tool start up on 20A circuits (with 12 gauge wire). no need to change anything, at least according to my electrician. all my stationary power tools are on 20A circuits with 15A outlets. haven't stalled or fried anything yet. BTW, never use the stab connectors on the back of outlets. again, this is what my licensed electrician advises.

[Troy Turner]

So on alot of ya'll's advice, I un-stabbed? de-stabbed? Took the wires out the back and wrapped them around the screw.

When I first ran my box and outlets, I was at our local electrical supply store. Told the guys what I was doing and they got me everything I needed. Figured they have to be right :D That was a few years ago and I've never had a problem. As I was running a new outlet, this was just one of those things that made me second guess myself. Sounds like they knew what they were talking about though.

Thanks again for all the replies...

[Steve Meliza]

I have an air compressor that makes an interesting case for why you might want a 20A circuit with a 15A corded device.

The rated amperage for the air compressor motor is 17.5A, but yet it comes with a 15A plug! The instructions say you can operate on a 15A circuit with no other loads connected, but if nuisance tripping occurs then switch to a 20A circuit. I did operate the compressor on a 15A circuit with only 15' or so of #14 wiring back to the breaker without any problems, but when I rewired the garage it got its own 20A circuit. So yes, sometimes a 20A circuit with devices having 15A power cords on them is a good idea.

[Ole Anderson]

One more thing to keep in mind: You are not allowed to load a circuit more than 80% of the breaker rating, therefore a 20 amp breaker should not have a connected load of more than 16 amps, a 15 amp breaker, no more than 12 amps. So technically Steve's compressor motor (which tends to run at full load unlike a saw) rated 17.5 amps should be on a 25 amp or larger breaker. This is critical on dust collector motors as they fequently run at full load for extended periods of time. Permanently connected motor loads have a different rule, but my head is already spinning reading this thread. I am sure someone out there will correct me.

[Anthony Whitesell]

For equipment supplied with a plug I've never given that much thought. Is it then legit for the instruction manuals to state to use 12g wire and a 20A breaker and be supplied with a cord with a 15A plug molded to the end, as is the case with my 60 gallon Craftsman and I suspect Steve's as well?

[Van Huskey]

One more thing to keep in mind: You are not allowed to load a circuit more than 80% of the breaker rating, therefore a 20 amp breaker should not have a connected load of more than 16 amps, a 15 amp breaker, no more than 12 amps. So technically Steve's compressor motor (which tends to run at full load unlike a saw) rated 17.5 amps should be on a 25 amp or larger breaker. This is critical on dust collector motors as they fequently run at full load for extended periods of time. Permanently connected motor loads have a different rule, but my head is already spinning reading this thread. I am sure someone out there will correct me.

You are getting into continuous load current vs non-continous load current situations. Unless the continuous load is 180 minutes or longer no derating is needed. The only thing I can think of in a hobby shop that would begin to hit this threshold is you DC if a blast gate was left open all the time. It would be rare to run any machine at FULL LOAD and no idling for near three hours.

Point being you can load a 20 amp circuit with a 20 amp load unless it is a LCL (long contiuous load) and run 180 minutes or more, if the breaker has a 100% rated frame, which you won't see in a house or hobby shop you wouldn't have to derate it either.

I did think of one other LCL you could see in a shop, that would be lighting.

[Pat Barry]

Its very confusing that the outlets are UL rated and have the holes in the back to allow the 'stabbing' isn't it? If that method was not acceptable to use (assuming the correct wire size) how could they get approval? I suspect that this is the electricians practice but not a requirement.

[Van Huskey]

Its very confusing that the outlets are UL rated and have the holes in the back to allow the 'stabbing' isn't it? If that method was not acceptable to use (assuming the correct wire size) how could they get approval? I suspect that this is the electricians practice but not a requirement.

Back sticking isn't against code but does limit them to a 15 amp circuit, the "hole" is not supposed to accept wire larger than 14g to prevent accidental or nefarious connection to 12g wire. It is quicker and easier and a LOT of houses are wired this way. An easy way to prevent an electrician from doing this is require all outlet circuits to be 20 amp.