Stuart in MN
Well-known member
The question was:
The answer to that is yes, so you guys can stop fighting about other stuff.
The answer to that is yes, so you guys can stop fighting about other stuff.
12-2 wire with 15A circuit?
- Thread starter pauls340
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1500hd
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wssix99
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This is an answer, but it may not be the correct one.
There isn't enough information in this thread to answer the question precisely.
If we are talking regular NM wire and a run 45 feet or less from the main panel, then yes - its safe. If it is a longer run, then 10ga could be required - yes, for a 15A circuit.
Is a 15A run this long common? Probably not, but the OP could be living large in a big house where its a legitimate issue.
IMO - Its best to answer these kinds of questions from a more direct source of information. If you are a do-it-your-self'er and don't live in an area where your home requires conduit, this book is the best $10 you will ever spend and will cover everything needed for residential applications: (its also sold in most hardware stores)
joe_padavano
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Three pages on this thread? Seriously?
pattenp
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With your needless comment and my needless comment about your needless comment pushes it closer to 4 pages.
Nostraquedeo
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It's not about an answer at this point, rather egos and semantics......
Nostraquedeo
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This is an answer, but it may not be the correct one.
There isn't enough information in this thread to answer the question precisely.
If we are talking regular NM wire and a run 45 feet or less from the main panel, then yes - its safe. If it is a longer run, then 10ga could be required - yes, for a 15A circuit.
Is a 15A run this long common? Probably not, but the OP could be living large in a big house where its a legitimate issue.
IMO - Its best to answer these kinds of questions from a more direct source of information. If you are a do-it-your-self'er and don't live in an area where your home requires conduit, this book is the best $10 you will ever spend and will cover everything needed for residential applications: (its also sold in most hardware stores)
How about this.....IN MOST CASES, YES!
I mean, will a ball roll down a hill? Yes. On the GarageJournal, we need to know the type of grass, PSI in the ball, rotation of the earth in relationship to the moon to determine gravity, slope of the hill, type of material on the hill, type of ball, material on the ball, on and on and on and on. It kinda makes people hestitant to ask a question or answer a question. So, IN MOSTS CASES, yes the ball will roll down the hill. Maybe all answers shall be prefaced with "In most cases".
Yes, chances are, if you ask a question on an internet forum, especially an electrical question, you will be hard pressed to pick the correct answer from the many authoritatively presented choices. The expert "discussion" can become worthless babble to the user with the original question who is left without an answer to his question.
Kevin C
Well-known member
http://www.youtube.com/watch?feature=player_embedded&v=hAXm0dIuyug#!
Looks like it will only roll up hill.
James-W
Well-known member
When I wired my garage I used 12ga wire for the outlets, but I did not put more than 4 outlets on any of the 20a breakers. I figured that way I would be less likely to trip a breaker if I have some friends over and we are working on projects and happen to be using several power tools at the same time.
I used 14ga wire for the lights and I am using those squirley type energy saving fluorescent lights.
For the 220volt circuits (I have several) I used 12/3 with a ground (except for the welder) and there is no more than 2 outlets on a circuit breaker. That may be a bit of overkill, but I feel better about doing it that way.
One thing that is code for where I live, at least for a garage or anywhere where there is a cement floor or where you can potentially have standing water, is the first outlet must be a ground fault outlet. So for each of the outlet circuits the first outlet is a ground fault receptacle and then other 3 outlets can be regular 20a outlets.
I used 14ga wire for the lights and I am using those squirley type energy saving fluorescent lights.
For the 220volt circuits (I have several) I used 12/3 with a ground (except for the welder) and there is no more than 2 outlets on a circuit breaker. That may be a bit of overkill, but I feel better about doing it that way.
One thing that is code for where I live, at least for a garage or anywhere where there is a cement floor or where you can potentially have standing water, is the first outlet must be a ground fault outlet. So for each of the outlet circuits the first outlet is a ground fault receptacle and then other 3 outlets can be regular 20a outlets.
Charles (in GA)
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wssix99
Well-known member
If a thread is talking about a topic where a wrong answer can lead to something unsafe, its probably good a good idea.
BTW - This thread really isn't really a "simple" question. If it was, we could all buy do-it-yourself house wiring kits and the world wouldn't need electricians.
Charles (in GA)
Well-known member
The OP by the way did tell us he was using NM by way of the question posed by the title, 12-2 would refer to 12-2 NM cable. Not sure what else he could have meant by 12-2.
The OP's question, my take on it, was posed as a "is it LEGAL" to use 12-2 on a 15 amp circuit. I do not think he intended it to be a "I have this load, this length, this type of wire" what size should I use? type of question, but rather, is it OK to connect 12 gauge wire in a 15 amp circuit, implying the question "is there some reason why I cannot upsize to 12 gauge wire?"
This is somewhat of a "the sky is falling type of scenario" NEC says that you need to use 14 gauge wire on a 15 amp circuit. The OP gave us more than enough info. He wanted to upsize to 12 gauge on a 15 amp circuit (which would be a circuit protected by a 15 amp circuit breaker.)
YOU are suggesting that he might need 10 gauge wire, which is absurb as that is two sizes above what the code requires.
The southwire calculator says that 12 gauge, pulling a FULL 15 amp thru the wires, is good for 69+ feet with a 3% voltage drop. Increasing the voltage drop to 5% which is more commonly accepted for a branch circuit would give us 115+ ft at the full 15 amps.
Decreasing the the amps to 12 amps, which is 80% of the circuit capacity, on a 12 gauge wire, at 5% voltage drop, takes us to a whopping 144 ft.
Charles
The OP's question, my take on it, was posed as a "is it LEGAL" to use 12-2 on a 15 amp circuit. I do not think he intended it to be a "I have this load, this length, this type of wire" what size should I use? type of question, but rather, is it OK to connect 12 gauge wire in a 15 amp circuit, implying the question "is there some reason why I cannot upsize to 12 gauge wire?"
This is somewhat of a "the sky is falling type of scenario" NEC says that you need to use 14 gauge wire on a 15 amp circuit. The OP gave us more than enough info. He wanted to upsize to 12 gauge on a 15 amp circuit (which would be a circuit protected by a 15 amp circuit breaker.)
YOU are suggesting that he might need 10 gauge wire, which is absurb as that is two sizes above what the code requires.
The southwire calculator says that 12 gauge, pulling a FULL 15 amp thru the wires, is good for 69+ feet with a 3% voltage drop. Increasing the voltage drop to 5% which is more commonly accepted for a branch circuit would give us 115+ ft at the full 15 amps.
Decreasing the the amps to 12 amps, which is 80% of the circuit capacity, on a 12 gauge wire, at 5% voltage drop, takes us to a whopping 144 ft.
Charles
Last edited:
Nostraquedeo
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Using that logic, there is not any simple questions or answers to ANYTHING! Again, all this babbling does is confuse people and make them want to ignore all responses or feel overwhelmed and hire an electrician, but guess what......no matter which electrician you bring out, they are gonna have their own idea and interpretation of codes. In which case you could have probably done it yourself with a simple answer on here, if only you could get one! Really to answer any question 99.9% accurately about electrical would require the question to be posed in about book length with the answers presented in book volumes. Think about..........
Nostraquedeo
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Oh, and to address the comment about "do-it-yourself kits", where do you think these answers are being generated from. The answers are not quoting wisdom, rather codes and other references. So, with enough time a DIYer could elimate the need for electricians.
Speedy Petey
Well-known member
I disagree. I think discussions like this are productive and show different points of view.
Maybe, but many codes are pretty cut and dry. Meaning there is very little interpretation involved.
I disagree. Codes are codes. The rest is wisdom, knowledge and experience.
And this could be said for ANY trade or profession. Thing is, besides time, there is a very real need for aptitude. Some folks simply do not posses the physical aptitude or dexterity to do many kinds of physical work.So, with enough time a DIYer could elimate the need for electricians.
Charles (in GA)
Well-known member
Boy did you get that right. I am and aircraft mechanic. While some companies actually give hands on tests for hiring, I don't think my company does. Certainly a good mechanical aptitude test should be given. You know, the stack of gears and of gear A turns CW which way does gear D turn? or here is a box opened out flat, which will it most closely resemble when folded into a box, A, B, C, or D? That kind of stuff.
Many people simply do not have innate mechanical aptitude that is needed to successfully do mechanical tasks.
Carpentry is a different thing. I find that a carpenter needs a good eye for whether it "looks"right as the job goes and how stuff fits together, its different than mechanical aptitude. I do do carpentry, but am not comfortable with it, because I don't have that "eye" for it.
Charles
Nostraquedeo
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Of course you disagree.....anything else would be outside your MO....of course you disagree with that statement too.....It's all good, some people are like that. It's not good or bad, it just is...
Speedy Petey
Well-known member
The world would be a pretty boring place if everyone agreed. Don't you agree?
Kevin C
Well-known member
Trick question....
As far as right way and simple answers, when I first got interested in electrical a friends Dad mentored me for a while.
For the simple task of adding an outlet for a welder he outlined several different scenarios and the advantages and disadvantages of each one. One on one that first lesson lasted a couple of hours.
He could have just told me to buy XYZ and have been done with it. The reasoning and insight he taught me has lasted me 35 years.
Sure at times we can beat things to death, but there is also a good opportunity to learn not only how your doing something but perhaps why.
Delta74
Well-known member
Original question, YES its safe. use the 12 with the 15 amp breaker, its fine.
Original poster STOP READING.
alot of others, oh boy, where to start? nothing wrong with it, its safe, in SOME cases you use a breaker to protect the wire, is some cases its to protect the load, Motor loads are a good example, you can undersize the wire to running amps but will often breaker the motor to STARTING current that can sometimes be a big difference.
Cost, someone here said 30+ bucks a roll is not a small difference, maybe for you buying 1 roll at home depot, when we order, we order it by the pallet load, and the cost difference is very very small, often to the point why the hell are we buying 14??? for under 2 bucks a roll difference, its not worth the floor / shelf space to stock alot of 14.
now for all the YOUR GOING TO DIE IN A FIRE people, please. CEC new codes allow upto 25 amp on a 14 gauge wire, the whole wire size thing has gone up thrue the roof, more amps on each guage of wire, however the breaker or load has to be rated at 90 degree's for it, most are not, so we have to throw back to the 75 degree which puts 14g back into the 15 amp, but its perfectly code legal to run a 12g from a 20 amp breaker to a JB 1 foot out of the panel, splice into 14g, run 14 across the building, back into a JB go back to 12 to tie into the load.
and Kevin C, useing your Quote here ...Sure at times we can beat things to death, but there is also a good opportunity to learn not only HOW your doing something but perhaps WHY.
there is alot of right answers on here, and alot of wrong answers, people here do get stuck in the, the code says this...... but it also says...... something different in a different section, sometimes 4 different answers for the same question, the trick is figuring out what section applies, again, useing the motors example, basic branch circuit for a plug or light it says yada yada, go to Motor loads, it suddenly has smaller wire, much bigger breakers, then go to Compressor motors ( like air conditioning / freezer units NOT air compressors in our shops) and its again a whole different set of rules and values.
lighting circuits have max loads, depending on homes/garages / storage / industrial / TYPE of lights / voltage of lights / Starting voltage of lights , again the golden book of rules gets very murky.
if your really interested, see if you can get a NEW code book, and attend a lecture on the NEW code rules and changes, often community colleges will have a code class for the new changes and uses of the book. Like I said the NEW 2012 CEC book is so much of a joke, with all the changes the Errata and changes and clarifications to it are now the size of the code book, and still growing, they are talking about throwing it out and starting over.
Original poster STOP READING.
alot of others, oh boy, where to start? nothing wrong with it, its safe, in SOME cases you use a breaker to protect the wire, is some cases its to protect the load, Motor loads are a good example, you can undersize the wire to running amps but will often breaker the motor to STARTING current that can sometimes be a big difference.
Cost, someone here said 30+ bucks a roll is not a small difference, maybe for you buying 1 roll at home depot, when we order, we order it by the pallet load, and the cost difference is very very small, often to the point why the hell are we buying 14??? for under 2 bucks a roll difference, its not worth the floor / shelf space to stock alot of 14.
now for all the YOUR GOING TO DIE IN A FIRE people, please. CEC new codes allow upto 25 amp on a 14 gauge wire, the whole wire size thing has gone up thrue the roof, more amps on each guage of wire, however the breaker or load has to be rated at 90 degree's for it, most are not, so we have to throw back to the 75 degree which puts 14g back into the 15 amp, but its perfectly code legal to run a 12g from a 20 amp breaker to a JB 1 foot out of the panel, splice into 14g, run 14 across the building, back into a JB go back to 12 to tie into the load.
and Kevin C, useing your Quote here ...Sure at times we can beat things to death, but there is also a good opportunity to learn not only HOW your doing something but perhaps WHY.
there is alot of right answers on here, and alot of wrong answers, people here do get stuck in the, the code says this...... but it also says...... something different in a different section, sometimes 4 different answers for the same question, the trick is figuring out what section applies, again, useing the motors example, basic branch circuit for a plug or light it says yada yada, go to Motor loads, it suddenly has smaller wire, much bigger breakers, then go to Compressor motors ( like air conditioning / freezer units NOT air compressors in our shops) and its again a whole different set of rules and values.
lighting circuits have max loads, depending on homes/garages / storage / industrial / TYPE of lights / voltage of lights / Starting voltage of lights , again the golden book of rules gets very murky.
if your really interested, see if you can get a NEW code book, and attend a lecture on the NEW code rules and changes, often community colleges will have a code class for the new changes and uses of the book. Like I said the NEW 2012 CEC book is so much of a joke, with all the changes the Errata and changes and clarifications to it are now the size of the code book, and still growing, they are talking about throwing it out and starting over.