Add light off a 20 Amp wire?
Buttkickski
| Posted in Energy, Heating & Insulation on
I want to add a light to the corner of my shop. There is a 20amp outlet about 8 feet from where I want my light to be. Can I pull power from that outlet to my switch then to a ceiling light?
Can I use 14 gage wire to do it??
Replies
Yes, you can add a light.
No it can't be #14.
Note, it is generally recommended that you don't have lights on a shop receprtacle circuit because you don't want it to go dark if you overlaod it.
But I am guessing that this is an addtional light and would not be a problem.
Also know that a few werid locals don't allow lights on 20 amp circuits and a few other don't allow anything, but 20 amp circuits.
But both of those are not common and not NEC.
.
A-holes. Hey every group has to have one. And I have been elected to be the one. I should make that my tagline.
OK It is an additional light for a corner that is pretty dark at times.So I'll run #12 from the receptacle to a switch to the light.I presume I need a 20amp rated switch, right.That saves me a LOT of work!Thanks.
"I presume I need a 20amp rated switch, right."No, you can use a 15 amp switch.The code is not perfect and this is one of the little stange corners.Using #14 would be safe for this, but would not meet code.I am guessing that the thinking is that run could be extended for another receptacle so you want it to be able to handle 20 amps.But the switch is not normally switching anything but a light fixture, which in this case would be less than 15 amps..
.
A-holes. Hey every group has to have one. And I have been elected to be the one. I should make that my tagline.
Got it, thanks!
What about this: Wire and extension cord to a surface mounted wall switch, the cable would just be held close to the wall by one of those decorative plastic sheaths (Wiremold makes these products, I think?). After the switch, the wire from the switch to the overhead light can be encased in conduit as normal.
Then it would be just like a standard desk lamp... just a little more heavy duty.Rebuilding my home in Cypress, CA
Also a CRX fanatic!
I don't think so. But one would have to read the code carefully.I don't think that cords can be permanately attached to a building surface..
.
A-holes. Hey every group has to have one. And I have been elected to be the one. I should make that my tagline.
Well, having the light plug into the wall makes it temporary, I would think.
I had a pair of sconces in a bedroom of the last house I lived in. Each had a switch on the bulb socket, and a cord to the outlet covered by the decorative Wiremold zipcord cover... what I proposed is based on that.
How about this then: Off that outlet he wires a 20amp switch to another outlet that he places on the ceiling. He plugs a conventional shoplight into that outlet. Switched outlet - no funny wiring.Rebuilding my home in Cypress, CA
Also a CRX fanatic!
You're not supposed to use extension cords for permanent wiring.
So convenient a thing it is to be a reasonable Creature, since it enables one to find or make a Reason for everything one has a mind to do. --Benjamin Franklin
<You're not supposed to use extension cords for permanent wiring>
Right, but what if you get a 25' length of zip cord, and rewire the light fixture just to have a really long cord?
Forrest
You can do that in a residence, so long as you're not selling it. Would be tagged by many commercial inspectors, though.
So convenient a thing it is to be a reasonable Creature, since it enables one to find or make a Reason for everything one has a mind to do. --Benjamin Franklin
Wire and extension cord to a surface mounted wall switch, the cable would just be held close to the wall by one of those decorative plastic sheaths (Wiremold makes these products, I think?). After the switch, the wire from the switch to the overhead light can be encased in conduit as normal.
NEC says that extension cords are for "temporary use". It doesn't really define that phrase well, but what you are proposing would not meet code, in my opinion.
Regarding the 14 guage wire, I find nothing in the NEC that would prohibit that. Around here, it's fairly common practice. Perhaps Bill will explain why he views that as a code violation.
Regarding the 14 guage wire, I find nothing in the NEC that would prohibit that. Around here, it's fairly common practice. Perhaps Bill will explain why he views that as a code violation
Article 240 - Overcurrent Protection , Section 4(D): Unless specifically permitted ....... the overcurrent protection shall not exceed 15 amperes for 14 AWG, 20 amperes for 12 AWG and 30 amperes for 10 AWG copper.........
There are a few exceptions for tap conductors and a list of specific applications relating to things like motors, capacitors, some control wiring, etc.
Ed
Article 240 - Overcurrent Protection , Section 4(D): Unless specifically permitted ....... the overcurrent protection shall not exceed 15 amperes for 14 AWG, 20 amperes for 12 AWG and 30 amperes for 10 AWG copper.........
Good point. If the breaker is a 20A breaker, then I agree, 14 AWG would not be permitted.
The OP stated he had a 20A outlet, but did not state the breaker size. The situation I had in mind was 20A rated receptacles on a 15A breaker - and in that case, 14 guage wire would be OK, because of the 15A breaker.
It's a 20amp breaker and I'm not changing it.
"It's a 20amp breaker and I'm not changing it."A 20 amp receptacle is a waste of money.In residential grade devices only come in 15 amp devices (those are the 59 cent ones).Spec grade (and higher) come in both 15 and 20 amp versions. And with or without backwiring. They start at around $1.75.You would can be the better quality devies in 15 amp versions and save a little money.Unless you have something with a 20 amp plug on it..
.
A-holes. Hey every group has to have one. And I have been elected to be the one. I should make that my tagline.
Bill,
"A 20 amp receptacle is a waste of money."
Well, not exactly. There's a circuit design issue and a code issue here.
If you look at Table 210.21(B)(2) you will see that the maximum allowable plug-in load to a receptacle is 80% of it's nominal value. For a 15a device that is 12a and for a 20a device that is 16a.
So when an electrician installs an outlet on a 20a circuit he has to take into account what will plugged into it. For example on a kitchen counter it's not a bad idea to use 20a-rated devices because of the probable loads that will be attached, possibly simultaneously. If I'm wiring an outlet that will have an 12a appliance plugged in, then I would certainly use a 20a duplex rather than a 15a duplex which would work but would be maxed out according to Table210 and would be overloaded if someone plugged something else into it.
The only 120v straight-blade 20a plugs I've come across are in non-residential settings, like commercial production, which use specialized equipment.
Ed
"If you look at Table 210.21(B)(2) you will see that the maximum allowable plug-in load to a receptacle is 80% of it's nominal value. For a 15a device that is 12a and for a 20a device that is 16a."Here is what that section says."(2) Total Cord-and-Plug-Connected Load Where connected to a branch circuit supplying two or more receptacles or outlets, a receptacle shall not supply a total cordandplug-connected load in excess of the maximum specified in Table 210.21(B)(2)."I have had too much wine to try and decipher this one.It heavey mixes total with INDIVIDUAL..
.
A-holes. Hey every group has to have one. And I have been elected to be the one. I should make that my tagline.
And also see 210.23(A)"(A) 15- and 20-Ampere Branch Circuits A 15- or 20-ampere branch circuit shall be
permitted to supply lighting units or other utilization equipment, or a combination of
both, and shall comply with 210.23(A)(1) and (A)(2).And the Handbook has this comment."A revision to
210.23(A)(1) clarifies that only cord-and-plug-connected utilization equipment that is
not fastened in place can have a rating of up to 80 percent of the branch circuit rating
where the circuit also supplies other loads. Equipment that is fastened in place, whether
direct wired or cord and plug connected (waste disposers and dishwashers for
example), is covered by the 50-percent requirement in 210.23(A)(2)."That says that I could plug in a 15 amp load into a 15 amp receptacle on 20 amp circuit.That is where I see many stationary equipment that comes with 15 amp plugs, but should be 20 amp.I have looked on my Jet TS for example and it has a UL motor. And a UL cordset. But the table saw as such is not UL listed..
.
A-holes. Hey every group has to have one. And I have been elected to be the one. I should make that my tagline.
And the Handbook has this comment.
"A revision to210.23(A)(1) clarifies that only cord-and-plug-connected utilization equipment that isnot fastened in place can have a rating of up to 80 percent of the branch circuit ratingwhere the circuit also supplies other loads. Equipment that is fastened in place, whetherdirect wired or cord and plug connected (waste disposers and dishwashers forexample), is covered by the 50-percent requirement in 210.23(A)(2)."
That says that I could plug in a 15 amp load into a 15 amp receptacle on 20 amp circuit.
Hi Bill,
I don't see any relationship between your conclusion and the section/commentary you quoted.
210.23(A)(2) is about circuit design , i.e. the 50% limitation when sharing fixed equipment and other loads, and is not only about receptacle loads . It is not particularly relevant to how much current a 15a duplex device can handle.
?
Ed
Edited 5/11/2007 10:23 pm ET by edlee
Edited 5/11/2007 10:27 pm ET by edlee
Uhhh...not sure I follow you; when I built the shop I wired two circuits with 5 receptacles each. Each circuit has 20a receptacles, #12 wire and a 20a breaker. I'm pretty sure I didn't pay any more than $1.75 for each receptacle. Are you thinking I bought something else?
Whatever the cost you could have gotten 15 amp rated receptacle of the same quality for less than the 20 amp.(Assuming that you paid "fair market price" and they wheren't surplus from a project or something like that..
.
A-holes. Hey every group has to have one. And I have been elected to be the one. I should make that my tagline.
Edited 5/7/2007 10:43 pm by BillHartmann
I see what you're saying, but what would have happened when the inspector saw 15a receptacles on a 20a circuit?
What should happen?
So convenient a thing it is to be a reasonable Creature, since it enables one to find or make a Reason for everything one has a mind to do. --Benjamin Franklin
I think the inspector should fail the electrical because the receptacles say 15a on them but they're installed in a 20a circuit.
Show me in the code where that's a violation.
So convenient a thing it is to be a reasonable Creature, since it enables one to find or make a Reason for everything one has a mind to do. --Benjamin Franklin
I don't know... I'm not arguing, I'm asking.
SO what's the answer? Can someone put a 15a receptacle on a 20a circuit?
All (UL recognized) "15 amp" receptacles are rated for 20 amps feedthrough, and, as a practical matter, have contacts that will handle 20 amps. (You see more difference in contact quality and current capacity between "lines" of receptacles than you do between the 15 and 20 amp units of the same "line".)So the only significant difference between the two is the T slot on the 20A unit. This is mostly useless (hardly any devices made with 20-amp 120V plugs) except to inform the user that the outlet is (probably) connected to a 20-amp circuit.Code permits 15A receptacles on a 20 amp circuit.
So convenient a thing it is to be a reasonable Creature, since it enables one to find or make a Reason for everything one has a mind to do. --Benjamin Franklin
Good, that's nice to know, but the question still stands: would an inspector fail a 20a circuit with 15a receptacles?
Read my post #16 and look up the Code reference. What more do you want than that?
"On a 20a circuit however, if there is more than one outlet, the devices can be rated at 15a or 20a."
First, I didn't catch that last sentence of your post 16 because it wasn't addressed to me, sorry. Second, I don't think I have access to the NEC so sorry again. Third, all I wanted was a simple "yes" or "no" answer so please excuse me for asking.
If you want a simple "yes" or "no" you need to be going to a different BBS.
So convenient a thing it is to be a reasonable Creature, since it enables one to find or make a Reason for everything one has a mind to do. --Benjamin Franklin
O.K., then, here's your answer:
yes or no
Cliff
p.s. or the answer could be:
no or yes
C.
I think the inspector should fail the electrical because the receptacles say 15a on them but they're installed in a 20a circuit.
that happen to me, it didnt care what it said, it had to have the funny slots. That what happen when wally world lays off the xmas help.
The OP stated he had a 20A outlet, but did not state the breaker size. The situation I had in mind was 20A rated receptacles on a 15A breaker - and in that case, 14 guage wire would be OK, because of the 15A breaker.
You're right about him not stating the breaker size........I assumed it when he said there was a 20a outlet. But that's because, I suppose, I know of this section of the NEC:
Table 210.21(B)(3) - Receptacle Ratings for Various Size Circuits.
The table shows that with a circuit rated at 15amps, the receptacle rating is to be "not over 15 amperes". So, putting 20a rated receptacles on a 15a circuit is not allowed.
On a 20a circuit however, if there is more than one outlet, the devices can be rated at 15a or 20a.
Ed
Edited 5/7/2007 11:44 am ET by edlee
Table 210.21(B)(3) - Receptacle Ratings for Various Size Circuits.
The table shows that with a circuit rated at 15amps, the receptacle rating is to be "not over 15 amperes". So, putting 20a rated receptacles on a 15a circuit is not allowed.
I'll have to dig out the code book when I get back to the office to look up that section - I don't recall that specifically off hand.
I suspect, though, that they are referring to 20A receptacles - i.e. receptacles designed to accept a 20A plug - as opposed to receptacles rated for 20A but that only accept 15A plugs (i.e. the 'normal' plugs). Many "15A" receptacles are rated for 20A, and many GFCI receptacles are rated for 20A. The difference is that they will not accept a 20A PLUG, not that they are rated for 20A.
I love it when the code books come out in these threads!
I suspect, though, that they are referring to 20A receptacles - i.e. receptacles designed to accept a 20A plug
Well, yeah by definition that is EXACTLY what we're talking about. A receptacle rated at 20a is a receptacle rated at 20a.
as opposed to receptacles rated for 20A but that only accept 15A plugs (i.e. the 'normal' plugs). Many "15A" receptacles are rated for 20A, and many GFCI receptacles are rated for 20A.
I think you're being confused by terminology. Duplex receptacles have their rating printed on them and 15a means 15a. We're not talking "feed-thru" rating here.
210.21(B)(3) allows a receptacle rated at 15a to be installed on a 20a circuit, as long as there is more than one outlet. This is "feed-thru" and is in a sense an exception to the general rule, based on load diversity. But the device itself is rated at 15a.
15a GFI devices usually say on the back that they are rated for 20a feed-thru. Their rating though in regards to the table and 210.21(B)(1) is 15amps.
These are the 15a Leviton duplex receptacles I use all the time, even in residential applications. I don't bother with the residential grade devices. Notice that there is no mention of 20a.
http://www.leviton.com/OA_HTML/xxlcfbuibeCSrdSrchResults.jsp?cg=&kw=cr15&ds=0&dr=20&st=kw&cpg=0
Ed
Edited 5/7/2007 3:08 pm ET by edlee
15a GFI devices usually say on the back that they are rated for 20a feed
OK, but that's not what I was referring to. A 20A plug has one blade turned:
http://servertech.com/downloads/Technical%20Notes/notes_pt_cordconectoropts.pdf
see NEMA 5-20P, for example. My thought was that they were referring to receptacles designed to accept a 20A plug, but as I said in the other message, after looking at that table I agree with your interpretation, and it seems that is not what they meant.
I get what you're saying.
There probably are 120v 20a straight-blade receptacles that will accept ONLY a 20a plug, i.e. blade turned. But what I'm used to seeing, at least for in-wall devices, is the combination, i.e. rated at 20a but has both neutral slots so that it will take 15a or 20a plug.
Nice talking with you............Ed
"These are the 15a Leviton duplex receptacles I use all the time, even in residential applications. I don't bother with the residential grade devices. Notice that there is no mention of 20a."Those same device are available in 20 amp versions.I would have to look up the some of them, but the CR15's are available in CR20's.But I have never seen anything with a 20 amp plug on it. Although some woodworking tools should probably have them. Some one did tell that they did see one on some resturant equippment.AFAIK ALL 15 amp UL DUPLEX receptacle are rated for 20 amps load. That is why you can use them on 20 circuits. That 20 amps can be any combination of feed througn and/or loads connected to the 2 15 receptacles. For example 2 10 amp loads. Or a 15 load plus 5 amp feed through.Here is a links showing both the plug and receptacle configuration for NEMA straight blades.http://www.systemconnection.com/downloads/PDFs/NEMAPlugReceptacleConfigurations.pdfBoth 120 and 240 15 amp plugs will plug into their corresponding 20 amp receptacles.I don't think that the same follows for the 120/240 or 277 or 3 phase circuits..
.
A-holes. Hey every group has to have one. And I have been elected to be the one. I should make that my tagline.
The table shows that with a circuit rated at 15amps, the receptacle rating is to be "not over 15 amperes". So, putting 20a rated receptacles on a 15a circuit is not allowed.
After reading the actual code section, I agree with your interpretation. While I couldn't find any clarification of what they mean by "rating", it certainly seems a simple reading of that table would be the common interpretation.
Sorry for adding to the confusion.
Well, he CAN legally run 14 wire, so long as he changes out the breaker for a 15A one. Otherwise, it's against code.
Mike HennessyPittsburgh, PA
I still cannot understand using 15a breaker OUTLETS (with 14 g wire) as opposed to 20a breakers (with 12 g wire).
Who knows what someone may plug in the outlet later? Say work is being done in the area of a 15a with 14 wire, someone plugs in a heavy load power tool, another person turns on a hair dryer on the same curcuit.
Ok, the 15a breaker trips, soon enough if you are lucky.
Isn't this a hazard waiting to happen???
Huh?
I have a 20a outlet with #12 wire and a 20a breaker. All I am doing is pulling a light off of that circuit. What's wrong with that?
"I still cannot understand using 15a breaker OUTLETS (with 14 g wire) as opposed to 20a breakers (with 12 g wire).Who knows what someone may plug in the outlet later? Say work is being done in the area of a 15a with 14 wire, someone plugs in a heavy load power tool, another person turns on a hair dryer on the same curcuit.Ok, the 15a breaker trips, soon enough if you are lucky.Isn't this a hazard waiting to happen??? "No hazard.And you still have the possibility of overloading. If you have more than one receptacle each one could, in therory, be drawing 15 amps. For the basic duplex receptacle that is 30 amps.If you have #14 wire and 15 amp breaker the breaker will open and protect the circuit the same as if you had #12 wire and 20 amp breaker..
.
A-holes. Hey every group has to have one. And I have been elected to be the one. I should make that my tagline.
But seriously, if it's a 20 amp circuit (has a 20 amp breaker), then, NO you can't use 14 gage wire. The maximum overcurrent protection allowed for 14 gage wire (except in certain instances like for some types of fixed in place, hard wired motors) is 15 amps.
This is one of the most basic aspects of branch circuit wiring.
Anyone who thinks it's OK is very dangerously misinformed.
Cliff
well now hold on Tex. I may not be an electrician but I do understand the basic theories of electricity. I'm pretty sure that single light I intend to add is never going to draw 20 amps therefore 14g would be safe FOR THE LIGHT ONLY, but not legal according to code.
Well there Pilgrim...
You have a point, with the way you're wiring the circuit. What happens when someone adds more ligthing load, downstream of your undersized wire? O.K., not likely, I'll grant you.
But, and this is a big but, the branch circuit conductors have to be protected not just against overload, but also against faults. A fault, for instance, like a line-to-ground short. The 14 gage wire, according to the Code-making panels, is not adequately protected by a 20 amp overcurrent protection device (OCPD). Not enough copper in the wire to carry the considerable current before the breaker trips, the wire heats up, maybe a fire starts.
I've often wondered how much heating is allowed in a properly sized conductor under either max overload or fault current. But whatever the value, be it heat produced or temp rise under some plausible worst-case conditions, some body (UL, NFPA, or a contract testing lab to one of them) has done the tests and some engineer has drawm a line as to what's safe and what's not. And the Code-making panels have debated and decided that 15 amp OCPD and no greater is safe for 14 gage wire. And of course there are some exceptions.
I'm thinking there's no point to get into what might be safe but not Code compliant. In a bigger sense, there have been a lot of third-world buildings that have fallen down and burned down, because some builder made his own decisions as to what's safe.
So I don't mean to insult your intellegence. It seems like we're slaves to Code requirements, and that's not a bad thing. Could we get away with doing a lot less in some instances, and not have a life-safety problem? Probably. But why the heck go there, when the difference is a bit of 12 gage wire vs 14 gage?
Peace,
Cliff
"But, and this is a big but, the branch circuit conductors have to be protected not just against overload, but also against faults. A fault, for instance, like a line-to-ground short. The 14 gage wire, according to the Code-making panels, is not adequately protected by a 20 amp overcurrent protection device (OCPD). "Objection in the court.But you are are allowed to do with with taps and motor circuits. And the breaker will protected it against faults.As I said earlier I think that the main reasoning is that some will will see #14 and think that then can extend the circuit with #14 and then you have problems with overload protection..
.
A-holes. Hey every group has to have one. And I have been elected to be the one. I should make that my tagline.
I liked my reason better. And technically #14 CAN handle 20A (it's in one of the NEC charts), it's just a "special case" (footnote to the chart) to limit it to 14A, probably because it's used in the type of circuits most likely to be abused.
So convenient a thing it is to be a reasonable Creature, since it enables one to find or make a Reason for everything one has a mind to do. --Benjamin Franklin
Scheist, Bill!
Yes, you're right. So is it the Copper Development Association that influenced the CMP to limit 14 gage copper branch circuit condictors to 15 amp OCPD, except in some specific circumstances? Sell more copper that way, maybe?
Cliff
Oh, I totally agree with you and the code for those very reasons. I just wanted you to know that I know what kind of wire is needed to handle 20a.Thanks.
The main concern is for the bozo who removes the bulb and replaces it with one of those outlet plugs, then hangs his toaster and microwave off of that.
So convenient a thing it is to be a reasonable Creature, since it enables one to find or make a Reason for everything one has a mind to do. --Benjamin Franklin
I agree and I'm using 12g as BillH and the code told me too.