14/2 14/3 romex in residential construction

[kwired]

How do you figure that there is MORE labor? Please don't say that the #12 is harder to work with.

It is a little harder to work with and takes a little more time. The total amount of time for the average receptacle outlet is not much different from using 14. Time saved will not show up much for just one bedroom in a house, may be a little noticeable for the entire house, and will probably be fairly noticeable for a multiple home development project.




Amount of heat lost by battery chargers or other low current use products?

Amount of heat is going to depend on what the load is as well as size of conductor. Putting 100 chargers on 14 AWG will generate more heat than putting each one on an individual 14 AWG.

 

[jaylectricity]

Bigger outlet boxes cost more, yellow wirenuts instead of orange. Red wirenuts instead of yellow. Some places don't allow stacking two 12-2 cables under one staple. Can't backstab (I don't usually, but some businesses price based on backstabbing). Heavier to carry per roll. Bigger holes in framing members require bigger drill bits, excess wear on power tools.

I'm not knocking anybody who uses 12 for every circuit at all. I'm just stating the extra costs of using it as opposed to the cost savings that were posted earlier. I haven't done the whole math problem. Maybe they cancel out or maybe one is indeed better.

This should probably go the way of the ground-up/ground-down argument.

 

[Speshulk]

How do you figure that there is MORE labor? Please don't say that the #12 is harder to work with.

Well . . . it's harder to work with, for one.

 

[Minuteman]

Bigger outlet boxes cost more, yellow wirenuts instead of orange. Red wirenuts instead of yellow. Some places don't allow stacking two 12-2 cables under one staple. Can't backstab (I don't usually, but some businesses price based on backstabbing). Heavier to carry per roll. Bigger holes in framing members require bigger drill bits, excess wear on power tools.

I'm not knocking anybody who uses 12 for every circuit at all. I'm just stating the extra costs of using it as opposed to the cost savings that were posted earlier. I haven't done the whole math problem. Maybe they cancel out or maybe one is indeed better.

This should probably go the way of the ground-up/ground-down argument.

All excellent points. But, it is what it is. AHJ says #12 in residential and commercial. I'm just saying that I continue to install only #12 in the juridictions where I don't have to. Seems I'm not alone. I rarley see #14.

 

[stickboy1375]

Once you go 14awg, you never go back.

 

[Minuteman]

Once you go 14awg, you never go back.

:happyno:

 

[electricguy61]

Legal in all jurisdictions in the San Francisco Bay Area that I work in.

Since the AFCI requirements, I run one 15amp circuit per bedroom for lights and receptacles (Makes troubleshooting easier). Never had a problem.

 

[kwired]

All excellent points. But, it is what it is. AHJ says #12 in residential and commercial. I'm just saying that I continue to install only #12 in the juridictions where I don't have to. Seems I'm not alone. I rarley see #14.

Aside from AHJ requiring it, there is no right or wrong.

Lets say we are wiring a new home and we have an area with 4 bedrooms.

Many of the guys that exclusively use 14 AWG will run 1 circuit per room. They will have 4 AFCI breakers and likely more feet of cable than some other methods.

The ones that do the same with 12 AWG just have more expensive cable for the most part, and maybe a little extra labor because 12 is a little harder to work with, but no so much more it will be that noticeable.

You then have those that may opt for using all 12 AWG but maybe reduce number of circuits - this will cost less in AFCI breakers, and probably in amount of money spent on copper - all depends on some installation practices.

I like to use 12 AWG for receptacle outlets, will not put one room per circuit, often will catch receptacles on opposite sides of a wall on same circuit unless not allowed like a bath, kitchen, etc. The lighting outlets I generally put on 14 AWG.

In the 4 bedrooms example I likely would have two 20 amp circuits supplying the receptacles, and a 15 amp circuit supplying the lighting - and the lighting circuit likely will also have lighting in additional rooms on the circuit.

I kind of figure cost is somewhat the same. Where I use more cost in material in one method I may spend less on labor. Sometimes a little more cost for better performance may be worth it.

I don't normally don't get involved with doing it as cheap as possible. That is just not how I install things. I consider things to keep cost down but do not dwell on them.

 

[stickboy1375]

You could have 4 bedrooms on one AFCI circuit if you really wanna save some money... There is no load in bedrooms as far as Im concerned.

 

[kwired]

You could have 4 bedrooms on one AFCI circuit if you really wanna save some money... There is no load in bedrooms as far as Im concerned.

You could also have the living room, family room, den, sunroom, parlor, library, recreation room, outdoor outlets, garage, basement, attic, lighting outlets in kitchen, dining, breakfast room, pantry and other similar rooms, and I might have missed a few others on the same circuit if you wish also.

If you do put all of that on one circuit there could be performance issues, but it is code compliant.

You can not have the kitchen, dining room, breakfast room, pantry, bathroom, laundry outlet, or anything otherwise requiring an individual branch circuit on that same circuit.

 

[Strife]

Always been allowed in Iowa. I know Chicago prohibits all NM specifically, not just 14.

They prohibit MC also. And anything flexible more than 4 feet.
Conduit only from what I understand.
Keeps labor hrs up.
Not gonna say the next thing.

 

[mlnk]

Again; less wire, fewer home runs, fewer AFCIs. Money saved.

At 3 watts/SF #14 will cover 600 SF, #12 will cover 800 SF. Only certain size houses will have fewer home runs, fewer circuits. For example a 1601 SF to 1800 SF house will need 3 #14 circuits or 3 #12 circuits. But an 1801 to 2400 SF house will need 4 #14 circuits.

 

[mlnk]

You could also have the living room, family room, den, sunroom, parlor, library, recreation room, outdoor outlets, garage, basement, attic, lighting outlets in kitchen, dining, breakfast room, pantry and other similar rooms, and I might have missed a few others on the same circuit if you wish also.

If you do put all of that on one circuit there could be performance issues, but it is code compliant.

You can not have the kitchen, dining room, breakfast room, pantry, bathroom, laundry outlet, or anything otherwise requiring an individual branch circuit on that same circuit.

That is a lot of rooms in a 800 SF house!!! Load does not matter here, NEC limit is 800 SF per 20 amp circuit for lighting and general use. Some AHJs change this to 500 SF

 

[mlnk]

They prohibit MC also. And anything flexible more than 4 feet.
Conduit only from what I understand.
Keeps labor hrs up.
Not gonna say the next thing.

Do you know why NM is prohibited in some AHJs? Mice, rats cause fires.

 

[kwired]

At 3 watts/SF #14 will cover 600 SF, #12 will cover 800 SF. Only certain size houses will have fewer home runs, fewer circuits. For example a 1601 SF to 1800 SF house will need 3 #14 circuits or 3 #12 circuits. But an 1801 to 2400 SF house will need 4 #14 circuits.

Table 220.12 gives us 3VA per square foot to be used for determining size of feeder or service. The title of 220 also says branch circuit. But then as you go through content it is not quite that simple. There are areas where 3VA just is not enough and others where it is more than is needed. Do you run branch circuits according to 3 VA per sq ft or do you run them to actual connected load?

220.12 also says "the calculated floor area shall not include open porches, garages, or unused or unfinished spaces not adaptable for future use." If you have a garage that someone uses for a workshop and has a fairly significant load in there at times - 220.12 still says it does not count towards the general lighting load - makes a lot of sense doesn't it?

 

[conmgt]

I hear other electricians all the time saying Philly doesn't allow #14 anything or 1/2" conduit in commercial applications...#12 and 3/4" is the minimum!...but I've asked Philly's L+I department and inspectors and none of them say it's true that's there's a ban on #14 and 1/2" conduit...never was.

About 5 years ago I was taking night courses at Drexel University for my Construction Management degree and in an Electrical course, a test question asked what was the smallest conductor allowed in commercial applications and I checked off #14. The answer was marked wrong. The professor said that an electrician he talked to said that #14 was banned in Philly commercial work. HA!

 

[Dennis Alwon]

Do you know why NM is prohibited in some AHJs? Mice, rats cause fires.

Rodents have been known to eat nm cable but I think there are other reasons such as nm being more prone to damage. I would not be surprised if there wasn't some lobbying being done because nm was too fast and job security might be at risk. That is a guess and I don't want to get political about it or blame anyone esp. since it is heresay.

 

[Strife]

Do you know why NM is prohibited in some AHJs? Mice, rats cause fires.

So why does Chicago prohibits MC as well?
They outta have some mighty rats out there.

 

[Strife]

Rodents have been known to eat nm cable but I think there are other reasons such as nm being more prone to damage. I would not be surprised if there wasn't some lobbying being done because nm was too fast and job security might be at risk. That is a guess and I don't want to get political about it or blame anyone esp. since it is heresay.

BINGO!
No hearsay, the main reason is the union lobbying against NM and MC.

 

[stickboy1375]

BINGO!
No hearsay, the main reason is the union lobbying against NM and MC.

I can run NM just as slow as EMT, so not sure what the issue is...