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| Subject - 12-2 vs 14-2 | |
| electric_man |
i was wondering how many of you use 12-2 for general purpose receptacles instead of 14-2 in houses. i know some builders who want entire lighting and recpt. run in 12-2 and i think there is no need for this . some electricians do it and i have ran the recpt. on it but only if the builder is willing to pay for it. as long as everything is sized correctly you should not have a problem and with a very small margine of mark up ever amount you can save helps you as long as you dont cut corners.. patrick |
| kbsparky | We usually install receptacles on 20 Amp circuits, and use the 14 gauge stuff for lighting only. Since the lighting is a fixed load, there is little chance that it will ever be overloaded. With the separation of the outlets and lights, no noticable dimming of the lights will occur when someone plugs in a vacuum cleaner, or hair dryer in a bedroom. One thing that really makes a customer sit up and take notice is the lights dimming in a brand new house with supposedly new wiring the first time they vacuum out the bedroom. And that is not a good thing, for them to notice what they consider a deficiency like that the first week they live there 
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| lctrc789 | I have to agree that you can use 14-2 as the code states, but the code is a bare minimum at best. We use all 12-2 and never use 14-2 for anything, but that is our preference. Many contractors will use 14-2 and try to save money but not really a lot. I also always use more then the code states in kitchens,(2) 20 amp circuits. But that is a matter of preference as well, I install all fridges on their own circuits and always try to install lights on their own loads and no recpts. on a lighting load, but again I supersede the code in mnay ways. I do not have call backs for tripping circuits, I don't get load blank problems, (dimming etc.) I get many repeat customers for future work, and have a great word of mouth advertising. The best way to have customers is to use your head and don't be a penny pincher, in the long run I have found in 24 years now that it has worked quite well for me. Cheaper is not better, LOL |
| electric_man | i am the same way in that i have seperate lighting circuits and keep receptacles seperate and i have never had a problem in the past. i do realize that with the arc faults required now for each bedroom , which the county that i live in does not yet enforce , that some ec are putting each bedroom recpts. and lights on one circuit along with the smoke detectors of course. thanks...patrick |
| David Hyatt | I always run 12/2, it is a personal preference. I think in new homes it is almost a nesscity. From a contractors stand point is cost much more, and takes longer to install but I think it is still a good idea. |
| Electricman | We also keep our lighting and recpt loads seperate. We do although use 14 awg for recepts in bedrooms, and other living spaces. I always try to keep my lighting under the 80% but thats just me. I agree with everyone else here keeping seperate is a good thing, no dimming lights when using that 13amp vacuum cleaner
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| John A. Peters | If we use 14/2, for a set of rooms, we like to run 3 circuits where we could have used 2 circuits with 12/2. So 3 circuits X 15 amps is 45 amps available viruses 2 circuits at 20 amps is just 40 amps. We prefer to work with 14/2. It is just that bit more malleable to make the job a bit easier to work and there fore more enjoyable. |
| Ryan_J | I would used 14-2 for residential, personally. |
| Energreen | I just worked on a customer's house with many 14-2 receptacle/mixed load circuits. The complaint was tripping breakers. I measured current at the breaker on the worst offender. 14 to 15 amps. She was running a 1500 Watt cord and plug connected space heater, large screen television, and terarium heat & lighting all on receptacles tied to the same 15 Amp breaker. 1)Each of those loads can be considered continuous. Max Continuous load on a 15 Amp circuit is 12 Amps. 2)All she had to do was turn on another small load and the breaker tripped. 15 Amp circuits don't cut it for receptacles. You never know what will be plugged in. EG |
| Ryan_J | EG: In the case you are discussing, 12-3 and a 20 amp circuit wouldn't cut it either. The heater itself is 12.5 amps, plus the other continuous loads you desscribe would probably be more than 16. |
| Energreen | Hi Ryan_J, I'm guessing you may have overlooked where I wrote that the measured load was 14 to 15 Amps in that situation. So it was pushing the limit on the 15 Amp (14-2) circuit. If it were a 20 Amp (12-2) circuit in this case, it would have been a 75% actual measured load. I didn't look at the ratings on the other appliances, but the space heater had a 1500 Watt label on it. However, according to my clamp on fluke meter, the actual measured load was 14 to 15 Amps at the circuit breaker. Since the room(s?) in question, in an old house, was fed by one branch circuit, the home owner would have been better off if it had been a 20 Amp circuit. They wouldn't have had a problem. When we flipped the heater down to the 900 Watt setting, the total circuit load dropped to 10 Amps. I let the customer know that it would be better to have an additional circuit in that room if they're going to run the heater at 1500 Watts. 2002: 210.23(A)(1) tells me that running a 1500 Watt space heater on a 15 Amp receptacle branch circuit is a code violation. Such 1500 Watt appliances are not uncommon in my area. So how wise is it to install 15 Amp general use receptacle branch circuits? Basically, if the stores in your area sell 1500 Watt appliances, installing a 15 Amp circuit is an invitation to violating 210.23(A)(1). The customers said they'd leave the heater set at 900 Watts. In other words, they don't want to spend the money to add another 20 Amps load capacity to the room. So, there's another reason a 20 Amp circuit would have worked out better in the first place. Generally speaking, 15 Amp (14-2) general use receptacle branch circuits aren't the best idea. Regards, EG |
| John A. Peters | In an old house we would-a, could-a, should-a run at least two 15A circuits. How many plug outlets were on that one 20A circuit? How many rooms did it extend in to? I wonder if all the appliances were in one room, in which case I would have been wrong with my multi 15A circuit idea. |
| Energreen | Hi John, I think that 15 amp circuit was feeding receptacles in just the one room, which looks like it was added onto the back of the house some years ago. But it's possible it was tied to other loads I'm not aware of. I liked your idea when I read it. I was thinking of doing it myself. But when I got to thinking about the kinds of things people will plug into a receptacle, and I had just taken that trouble call, I realized that a 15 Amp circuit has too many limitations. Even when running two 15 Amp circuits instead of one 20 Amp, I'd want to think about 210.23(A)(1). That says a cord and plug connected appliance can't be rated higher than 80% of the circuit's ampacity. If a homeowner plugs a 1500 Watt rated load into a 15 Amp circuit, she's violating the NEC. How's she supposed to know that? If these heaters are UL listed and available at every department store in the area, who's really responsible to make sure the circuits that power them have enough capacity to meet the code requirements? I don't know the answer to that. But I know this is an issue. And I want to do a good job and take care of my customers. So I won't be installing any 15 Amp general use receptacle branch circuits. (Dedicated circuits are a different story.) Thanks to everyone for this discussion. EG |
| electric_man | you are right eg about the homeowner not knowing what they plug in might over load the circiut....the nec allows you to derate things like the oven for instance, they are saying most people are not going to turn on every burner and the oven at the same time but if they do then if you run a 40 amp circuit (if you have rated it at 8kw) then it will pull over 40 amps for sure.. if you install to the nec, i know it is the minimun, it is saying you have installed to meet the demands.....but it is best to exceed if necesssary....a lot of good replies patrick |
| Mike Delaney | Having multiple ckts supplying bedrooms gets expensive, each ckt has to be arc fault protected. We usually put bed #2 & #3 on one 15 amp ckt (about 8 recepts, 2 lights), and the master br and smoke detectors on a 15 amp circuit. I've wired probably a couple hundred houses that way, and never had a problem. What's the tipical load on a bedroom circuit?? (I don't think a significant amount) I usually count each opening as 1 amp...so ten openings would be ten amps, out of 12 amps maximum (80%). In the area I'm located, its competitive, there is no way you can compete with 12/2 vs. 14/2 and still make a good profit...thats the main reason I don't use 12, I have had some customers request it, not many though. |
| Energreen | *Smoke detectors are required to be on a separate circuit here. So that small load can't be shared on a bedroom circuit. It's smart to require a dedicated smoke detector circuit, because you wouldn't want a short or overload on a general use circuit to take out your smokes. But it requires an additional breaker no matter what. A smoke detector uses 50ma. So ten smoke detectors use 1/2 amp. That 15 Amp circuit will never trip for overloads. *The "typical" load for a dwelling is 3va/sqft from Table 220.3a. Figuring two 14x14 bedrooms and one 15x16 master bedroom (these sound big to me), 3 bedrooms are 632 sq. ft. Multiply that by 3va = 1896va for general loads in 3 bedrooms. That's under 80% load for ONE 20Amp circuit. The NEC doesn't put a limit on how many outlets there are on a residential branch circuit. But it does say a cord and plug connected appliance load can't be more than 80% of the circuit's capacity. Here in the Northeast, 1500 Watt space heaters are as common as coffee pots. We have two in our house. My neighbors have two. etc. I wouldn't be able to sleep at night if I installed 15 Amp receptacle circuits. I can cover those 3 big bedrooms with one 20 Amp circuit. ONE AFCI breaker instead of TWO. One home run uses less cable. One circuit instead of two takes less time. 210.23(A)(1) is less likely to be violated. Does this compete with two 15A circuits? Even if I used two 15A AFCI circuits for bedroom receptacles/lights, I'd still have to add a third for smokes to meet the state's requirements. EG |
| JimmyDee | quote: I always put them on the same circuit as the hall way light so if it gets shut off for any reason, you will not let it go. I think a dedicated circuit is totally unnecessary and a waste especially with the required battery backup units. Jim |
| Energreen | Hi JimmyDee, I don't have a choice. It's state law here. But on second thought, I think you're probably right. When the battery goes dead the smoke detector chirps. So a dead battery isn't going to stay there too long... won't create a hazard. Smoke detectors have to be in bedrooms. Every bedroom outlet has to be AFCI protected. I don't see where smoke detectors are exempt from this. Do you? EG |
| stedder | Here too Jimmy, smokes have to be on a circuit that would be a nusiance if tripped, at least thats what my friendly inspector wants to see. |
| John A. Peters | One 20A circcuit for three bedrooms means they can only use one heater. Maybe that is why the call them portable? :-) |
| kbsparky | quote: I agree with you on this. Put something else that is noticable on that smoke circuit, and it will be maintained better by the homeowners. Problem is, there are bureaucrats that make and enforce regulations on the rest of us, and by so doing, come up with some assinine requirements. For example, let's look at the requirements in Delaware: Smoke detectors are required to be on a separate, dedicated circuit with a lock-on installed at the panel, to prevent the breaker from accidently being switched off. No other loads may be connected to that circuit. The smokes are also required to be interconnected, battery back-up, and installed in each bedroom, as well as outside of every sleeping area, and on every floor. So what happens if that breaker just happens to trip? In most cases (unless you happen to have a Square D type QO panel) no one would even notice that the power was "off" since no other lights or devices would fail to operate. Only if the occupants are keenly aware of the power indicator lights on the units would someone even think to check the breaker. And with some panels, that lock-on device is a bear to remove to allow someone to reset the breaker --- it also would prevent the breaker handle from moving to the mid-way (tripped) position, so a visual inspection would not reveal that the circuit was tripped. (unless there was visi-trip® breakers present, as earlier stipulated) 
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| Wirenutz | dedicated lighting is really a more expensive job using either 14 or 12 (as JP alludes) , yet the one good reason i've found in doing so is ease in generator interfacing... the other angle is in system retrofits , i did have one request that the lighting be isolated to a subpanel to accomodate a possible future low voltage system |