14-2 vs 12-2 wiring?

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lumbajac

Member
Mar 15, 2008
85
Upper Peninsula, Michigan
Preparing to wire my new home and have bought 12-2 wire and 20A breakers for all baths, my basement workshop, garage, and the kitchen/dining area. Purchased 14-2 wire and 15A breakers for all other outlet circuits and lighting circuits such as living room, hallways, and bedrooms. Now I've been told by a couple of other people that they would run 12-2 with 20A instead of the 14-2 with 15A breakers everywhere.

I'm considering exchanging all of my 14-2 and 15A's (about 2000' worth) for 12-2 and 20's. Should I go with 12-2 and 20A's in the bedrooms as well since they require arcfault breakers? Should I go with the 12-2 just to "overwire" a bit in the bedrooms for potential future loads such as computers (is 14-2 sufficient or 12-2 necessary for computers)? Would I be wasting money and some time since 14-2 is cheaper and easier to work with?

Any thoughts/suggestions?
 
Absolutely go with 12-2 Wire and 20 Amp circuits. Not only are they less fire prone due to overloading, but you'll thank yourself later.

Other things to keep in mind:

Keep lighting off of wall plug circuits

Do not "Back wire" plugs. It takes longer to use the screw posts but it's far less prone to arcing and fires.

Pull at least one extra circuit to the far end of the house for future use. (trust me on this).

I always say spend a little more up front on the wiring so you only have to do it once.
 
Why do you think you need a 20 amp circuit? WOuld a 15 amp circuit do the job? I bet it will. Even your computer center will not need more than 15 amps. Cripes, that's 1550 watts. So why upsize? Bathrooms, garages, and utility rooms sure, there you will have hair dryers power tools and irons. I don't see the need to overwire everything unless you can show the need.
 
I agree with highbeam, plus 12 is a pain to get to go in the box cleanly.
 
Highbeam said:
Why do you think you need a 20 amp circuit? WOuld a 15 amp circuit do the job? I bet it will. Even your computer center will not need more than 15 amps. Cripes, that's 1550 watts. So why upsize? Bathrooms, garages, and utility rooms sure, there you will have hair dryers power tools and irons. I don't see the need to overwire everything unless you can show the need.

I guess I don't know if I will need 20 amp circuits or not... I know very little about wiring. I will be running lights and outlets separately.

What I do know is that my brother-in-law is having his breakers for his new home bedrooms tripping quite easily. He ran 14-2 wire with 15A breakers... lights and outlets separate from each other. He is blaming the issue on the required arcfault breaker. I do know that he has ran 3 bedrooms tied into one 15A arcfault breaker so this may be the issue... probably should have each bedroom running into their own individual arcfault breakers to avoid this problem? Or is the issue undersized wire and breakers... or a combination of the wiring, breakers, and arcfault? He's not plugging anything too heafty into the outlets other than alarm clocks, radios, etc.

Again, I don't know much about wiring so I'm just thinking out loud here and trying to figure out what I should do.

More thoughts and opinions would be welcomed and appreciated! Thanks.
 
I wouldn't bother with 12ga/20A unless you have a heavy demand, like in the kitchen. 14-2 is much easier to work with and 20 amp circuits really ought to have 20 amp devices on them ie: NEMA 5-20 receptacles. See: http://www.levitonproducts.com/catalog/dept_id_966.htm These are a usually a lot more expensive than 15 amp parts, due to the volume sold.

Arcfaults are a relative newcomer to home construction and I have heard about a lot of people having a lot of problems. The bigger the circuit (more receptacles) the greater the chance of a problem, so more smaller circuits should be better. I would suggest that your BIL pull each device on the circuit and check for loose wiring and yes, those back wired outlets (if you have them) will only cause a problem in the future. Put it all back together and see if you can narrow down which device causes the problem, if it recurs. It is possible to have a bad breaker that is too sensitive, but they all conform to the same standard, soooo.....

We all got along fine with regular breakers, even Federal Pacific only burned down a FEW houses!

Chris
 
Why skimp on the wiring people? Honestly how much additional cost will it add to the house? $500 maybe $1000? If he's planning on living in the house for a long time I definitely would go with 20 amp circuits not only is it less likely to trip with larger devices plugged in. Something I've also noticed that on certain combinations of lighting and motors 15 amp circuits will trip where a 20 won't because the inrush of current through a 15 amp breaker.
 
I just wired my addition. I used 14/2 & 14/3 for the separate lights & ceiling fan fixtures. 12/2 & 12/3 for the outlet circuits. Also ran separate circuits for the office & bedroom.
Have run my shopsmith in the bedroom while working on everything etc, all my power tools, no problems. I see no need to run 12 gauge for lighting circuits. I do suggest keeping lighting & receptacles on separate circuits.
I ran a new sub panel in the garage tapped off the main breaker panel. New code calls for arc fault breakers in the sub panel. I used em, they are expensive, but never had a problem with them. Did accidentally rub a hot terminal on a receptacle that is dangling from box until I get the walls sealed. Arc fault worked flawlessly.
 
One thing to keep in mind with lighting circuits is use of CFL's and future LED's. I think the code limits number of boxes on a circuit, but this might be silly for CFL lighting (not accounting for the hog, pardon the french, who goes with incandescent lighting). A 15 amp circuit, drawing 10 amps, would power at least 75- 15w CFL's, or 46- 25w CFL's (100 watt equivalent incandescent). Numbers are rounded.
 
I would agree that on lighting only circuits 14-2 would be appropriate as it's never going to see heavy amp loads however I would only tie 1 maybe 2 rooms on the same lighting circuit so that if it trips all the lights in one area of the house aren't all out at once like my house.

I swear a pack of chimps wired my house and the builders in charge didn't bother to do anything properly. I have the garage door opener on outlet circuits, lighting mixed with outlets and all sorts of foolish things.
 
sawdustburners said:
HD has booklets titled 'CODECHECK" which are very helpfull. u can browse them thru in store. or get an electrcian to draw u a plan. i would run 12-2 to all outlets & 14-2 to lights & hardwired smoke detectors which the codeman suggested should be on circuit which CANNOT be ignored so i put them on the light cicuit & he was happy. its a pain when the backup batteries need replacing but they cant be turned off with a breaker & forgotten.
With the demands of modern electrical code, the codechecks are great

I second this.
also. in my area, we need arc fault breakers for bed rooms. and 12 awg wire in bathrooms with gfi fault protection
 
As an electrician who has wired more than his share of houses i would be happy to help.

20 amp circuits for bedrooms is a little on the over kill side, unless you plan on running window a/c units in the bedrooms. I like to put 1-2 bedrooms per circuit depending on size. For example 2 small or medium sized bedrooms on a circuit, the master bed and bath lighting on it's own circuit. I Prefer to run dedicated 20 amp circuits to the bathroom outlets that are near the bedrooms. (Code is 1 20 amp bathroom circuit could cover the entire house)

I prefer to run a dedicated NON GFI circuit for the fridge, also another dedicated 20 amp circuit if you have an over the range micro wave.

Like others have said don't use the backwire (stab in) connections on outlets and switches. Nor daisy chain switches ( strip a little insulation, wrap around the screw and repeat until all the switches in a box are wired) take the time and make a good slice.

Good practice is a spare circuit up into the attic, or even better a spare conduit for future.

As others have said arc-fault breakers are required every where now, the exception is fixed appliances (garage door openers, furnaces, dryers, ranges, sump pumps etc and anything thats GFCI protected).

As far as arc fault breakers tripping, older vacuum cleaners, or any appliance that the brushes are worn out could cause it to trip. This was true for the older arc fault breakers, the newer ones seem to be a little less sensitive. You must make sure you keep your neutrals separate in multi gang boxes, as this could cause un-wanted tripping.

there is no max amount of boxes or devices that may be placed on a circuit, in residential anyways.

I like to also install a 200 amp service in the house regardless of size, because the price difference in materials is about $300 ish. This is not always practical in spec houses or duplex houses, those the builder usually requests the bare minimum allowed by code.

Re: u8at711. 2008 NEC (not adopted every where yet) Requires arc faults for almost all circuits now, and a 20 amp GFI in bathrooms has gone back to at least the 96 code cycle.

Any other questions ask here or feel free to PM me.
 
I'd generally agree on 14-2 for lighting and 12-2 for wall plugs, but overall run more circuits. My parents did a pretty serious remodel a few years back, and every room has separate plug and lighting circuits. Makes any kind of work really easy, plus it's all labeled, which takes a lot of the excitement out of electrical work :cool:

Steve
 
seige101 said:
As an electrician who has wired more than his share of houses i would be happy to help.

20 amp circuits for bedrooms is a little on the over kill side, unless you plan on running window a/c units in the bedrooms. I like to put 1-2 bedrooms per circuit depending on size. For example 2 small or medium sized bedrooms on a circuit, the master bed and bath lighting on it's own circuit. I Prefer to run dedicated 20 amp circuits to the bathroom outlets that are near the bedrooms. (Code is 1 20 amp bathroom circuit could cover the entire house)

I prefer to run a dedicated NON GFI circuit for the fridge, also another dedicated 20 amp circuit if you have an over the range micro wave.

Like others have said don't use the backwire (stab in) connections on outlets and switches. Nor daisy chain switches ( strip a little insulation, wrap around the screw and repeat until all the switches in a box are wired) take the time and make a good slice.

Good practice is a spare circuit up into the attic, or even better a spare conduit for future.

As others have said arc-fault breakers are required every where now, the exception is fixed appliances (garage door openers, furnaces, dryers, ranges, sump pumps etc and anything thats GFCI protected).

As far as arc fault breakers tripping, older vacuum cleaners, or any appliance that the brushes are worn out could cause it to trip. This was true for the older arc fault breakers, the newer ones seem to be a little less sensitive. You must make sure you keep your neutrals separate in multi gang boxes, as this could cause un-wanted tripping.

there is no max amount of boxes or devices that may be placed on a circuit, in residential anyways.

I like to also install a 200 amp service in the house regardless of size, because the price difference in materials is about $300 ish. This is not always practical in spec houses or duplex houses, those the builder usually requests the bare minimum allowed by code.

Re: u8at711. 2008 NEC (not adopted every where yet) Requires arc faults for almost all circuits now, and a 20 amp GFI in bathrooms has gone back to at least the 96 code cycle.

Any other questions ask here or feel free to PM me.

Not planning on running bedroom window A/C units as I am having an airconditioning coil installed in my furnace; not going to have an air conditioning unit quite yet, but the coil is in place. Will likely run separte light and outlet circuits - 14-2 for both in bedrooms, hallways, and living room. Will run 12-2 in kitchen, dining, basement workshop, and garage.

Thanks
 
I didn't realize those arc fault breakers were required everywhere now. I think I just have them in the bed rooms in our 5 year place.
Is it worthwhile retrofitting those breakers? Do they provide much more protection? I have to read more about them.

If you were going to power your house occasionally with a portable or standby generator, now would be the time to make provisions for that.
It's not that fancy, but I found a simple generator interlock kit by SquareD, but even that required the upper right two breaker positions so I had to move the stove breakers. Luckily I found enough slack in the wire.
 
velvetfoot said:
I didn't realize those arc fault breakers were required everywhere now. I think I just have them in the bed rooms in our 5 year place.
Is it worthwhile retrofitting those breakers? Do they provide much more protection? I have to read more about them.

If you were going to power your house occasionally with a portable or standby generator, now would be the time to make provisions for that.
It's not that fancy, but I found a simple generator interlock kit by SquareD, but even that required the upper right two breaker positions so I had to move the stove breakers. Luckily I found enough slack in the wire.

Retrofit applications can be hard to do. Each circuit must have a neutral wire (white) all the way back to the panel (without being tied into other circuits) when using the arc-fault breakers. If the electrician who wired your house was good this shouldn't be a problem, but a lot of guys see white wires and splice them all together, it isn't really a code or safety issue. This is common in multi gang boxes where there is 3-way switches wired to different circuits.

Personally i wouldn't retro fit them in my house.

Yes they provide much more protection.

Definitely a good suggestion on adding provisions for the generator now!
 
lumbajac said:
seige101 said:
As an electrician who has wired more than his share of houses i would be happy to help.

20 amp circuits for bedrooms is a little on the over kill side, unless you plan on running window a/c units in the bedrooms. I like to put 1-2 bedrooms per circuit depending on size. For example 2 small or medium sized bedrooms on a circuit, the master bed and bath lighting on it's own circuit. I Prefer to run dedicated 20 amp circuits to the bathroom outlets that are near the bedrooms. (Code is 1 20 amp bathroom circuit could cover the entire house)

I prefer to run a dedicated NON GFI circuit for the fridge, also another dedicated 20 amp circuit if you have an over the range micro wave.

Like others have said don't use the backwire (stab in) connections on outlets and switches. Nor daisy chain switches ( strip a little insulation, wrap around the screw and repeat until all the switches in a box are wired) take the time and make a good slice.

Good practice is a spare circuit up into the attic, or even better a spare conduit for future.

As others have said arc-fault breakers are required every where now, the exception is fixed appliances (garage door openers, furnaces, dryers, ranges, sump pumps etc and anything thats GFCI protected).

As far as arc fault breakers tripping, older vacuum cleaners, or any appliance that the brushes are worn out could cause it to trip. This was true for the older arc fault breakers, the newer ones seem to be a little less sensitive. You must make sure you keep your neutrals separate in multi gang boxes, as this could cause un-wanted tripping.

there is no max amount of boxes or devices that may be placed on a circuit, in residential anyways.

I like to also install a 200 amp service in the house regardless of size, because the price difference in materials is about $300 ish. This is not always practical in spec houses or duplex houses, those the builder usually requests the bare minimum allowed by code.

Re: u8at711. 2008 NEC (not adopted every where yet) Requires arc faults for almost all circuits now, and a 20 amp GFI in bathrooms has gone back to at least the 96 code cycle.

Any other questions ask here or feel free to PM me.

Not planning on running bedroom window A/C units as I am having an airconditioning coil installed in my furnace; not going to have an air conditioning unit quite yet, but the coil is in place. Will likely run separte light and outlet circuits - 14-2 for both in bedrooms, hallways, and living room. Will run 12-2 in kitchen, dining, basement workshop, and garage.

Thanks
How about kids???
Mine both seemed to have everything in the world plugged in, stereos, playstations, computers........loads that bedrooms were not designed to handle...
Daughter loved to plug hair curler in and then blow dry her hair, while everything else was running, in the bedroom :roll:
I agree with most 14 for lighting and 12 for outlets.
and I agree with the thought of running 12 for everything..
In a nutshell though you can't just pack a 22 space 100 amp panel full of 20 amp breakers.
you need to calculate the load and then size the panel........ Like seige said 200amp seems to be the norm now anyway but it too can't be packed full of 20amp breakers.........You can run 12 throughout the house and hook up 15 amp circuits (and breakers) to it but you can't hook up a 20 amp breaker to a 14-2 (legally that is).
running 12-2 throughout can reduce costs in the future should you need to expand a circuit....
just my thoughts...... but with todays cost of copper if I had to do it allover again........ I'm not sure what I would do.
This probably won't help you will it???????? :-/
 
seige101 said:
velvetfoot said:
I didn't realize those arc fault breakers were required everywhere now. I think I just have them in the bed rooms in our 5 year place.
Is it worthwhile retrofitting those breakers? Do they provide much more protection? I have to read more about them.

If you were going to power your house occasionally with a portable or standby generator, now would be the time to make provisions for that.
It's not that fancy, but I found a simple generator interlock kit by SquareD, but even that required the upper right two breaker positions so I had to move the stove breakers. Luckily I found enough slack in the wire.

Retrofit applications can be hard to do. Each circuit must have a neutral wire (white) all the way back to the panel (without being tied into other circuits) when using the arc-fault breakers. If the electrician who wired your house was good this shouldn't be a problem, but a lot of guys see white wires and splice them all together, it isn't really a code or safety issue. This is common in multi gang boxes where there is 3-way switches wired to different circuits.

Personally i wouldn't retro fit them in my house.

Yes they provide much more protection.

Definitely a good suggestion on adding provisions for the generator now!
gotta love the shared neutral on the ground fault breakers too ;-P
 
GVA said:
gotta love the shared neutral on the ground fault breakers too ;-P

Don't get me started... lets just say nicely that the previous company i worked for and my co-irkers weren't the brightest bulbs. I've pulled my hair out plenty of times tracing out circuits that randomly trip.

The current company, i work with the owner and 2 other guys, mainly commercial and industrial. I am always told do it right, no matter how long it takes, go out and get anything you need in regards to tools and materials to get the job done. The pay and benefits are good too!
 
Running 20 amp circuits when not needed is not really an ideal practice, IMO (I am not an electrician or inspector, however).

The purpose of a circuit breaker is to protect an overload. Remember, you are going to be plugging in light wire (rated for 5 or 10 amps) into the outlets. If you have a problem in a light or appliance, you want the circuit breaker to trip quickly. In some situations, a 20 amp breaker might not trip allowing the power to flow until a fire started whereas a 15 amp might have tripped earlier.

Sure, it's a somewhat uncommon scenario, but I'm just pointing out that "bigger isn't always better" when you don't need it. Breakers should be sized for the expected load.

Of course, 12 ga wire with 15 amp breakers is fine, that won't cause the problem and if you ever really need it as a 20 amp circuit, you can easily replace the breaker.

As for Jim's rant against incandescent lighting, from all that I'm reading, CFL's are not all they are cracked up to be. They could turn out to be an environmental nightmare. If one breaks, you have a high risk situation with the mercury released. If it breaks onto carpet or furniture, the carpet or couch should be removed from the house and properly disposed of. Do not inhale the air without proper protection, etc. while you are cleaning up. And of course they don't last as long as advertised, especially in non ideal usage (frequent on/off, etc.) And who disposes of the burned out bulbs in an environmentally safe manner? Yep, we're sure going to save energy when I have to drive the car 30 miles to properly dispose of a burned out CFL. Right now I have a dozen burned out 4' flourescents sitting around the basement that I can't get rid of. This is good for the environment?

Just my $.02

Ken
 
I have the standard 14-2 house / 12-2 kitchen/garage. I can't ever remember tripping a breaker in the house...might have snapped one or two in the garage with space heater running, all ceiling lights on, 500W halogen work light, plus kicking on a chop saw which got stuck in the metal, 1/2 way through the cut.

IMHO, things are starting to use less electricity...not more. You may plug in a stereo, play station, TV, computer, cell phone, etc - and all that still won't use 1,000 watts. I guess if you plan to stay at your home for ever, you could spend the extra cash and be in a "better to have and not need rather than need and not have" mode. But if you're planning to move anytime in the next decade it would just be a waste. Even if you do trip a breaker - it's not the end of the world...just re-set it and move one or two items from that plug to another. I'd be willing to make a few trips to the basement breaker panel to save a couple thousand bucks.

One thing I have invested in (when remodeling kitchens/baths) is MORE plugs...as it seems like more things need to be plugged in today...my cell phone, wife's cell, computer, counter top appliances, various battery chargers, etc. So every place in my kitchen that would normally have been a single gang outlet, I put in a double. Though the cost of that is pretty minor - a buck for the box, few bucks for the receptacle and a few extra minutes to wire it up.
 
Do not “Back wire” plugs. It takes longer to use the screw posts but it’s far less prone to arcing and fires.

I have a question about recessed lights if you dont mind. You said dont use the push in posts on the back of outlets. How about the little plastic connectors that came on my Halo recessed fixtures .They replace the wire nut connectors and are push in types They were aready installed on the fixtures when I bought them. You simply stripped the wires and pushed them into the the little plastic connectors. Should I have cut these off and used a wire nut? Will I have future problems and should I take down the sheetrock and re-do before I plaster and it is too late? The attic area is not accessable. Thanks
 
ScottF said:
Do not “Back wire” plugs. It takes longer to use the screw posts but it’s far less prone to arcing and fires.

I have a question about recessed lights if you dont mind. You said dont use the push in posts on the back of outlets. How about the little plastic connectors that came on my Halo recessed fixtures .They replace the wire nut connectors and are push in types They were aready installed on the fixtures when I bought them. You simply stripped the wires and pushed them into the the little plastic connectors. Should I have cut these off and used a wire nut? Will I have future problems and should I take down the sheetrock and re-do before I plaster and it is too late? The attic area is not accessable. Thanks

They are known in the business as "insulation displacement" connectors and are great for low current connections, eg: comm wiring. The jury is still out on their use in household wiring. The concept is that you are attaching less than an amp of current to wiring that may be carrying much more than an amp. It's probably OK, but only time will tell how they pan out. I would rather use a wire nut, but I tend to err on the side of more traditional wiring practices.

If you are getting cold feet on your wiring job, you can pull out the housing from the ceiling without wrecking the sheetrock. The "can" is usually held in by a couple of sheet metal screws into the ring that mounts in the ceiling. After you drop the can, you can usually reach the junction box to access the wiring. Clip, strip and twist on a wire nut. Wire nuts are cheaper and more positive than an IDC, IMHO.

Chris
 
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