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View Full Version : 12 awg and 15 amp breaker-is this just overkill?



Marc M
09-19-2008, 07:28 PM
Is this makeup simply overkill or is there a potential issue here?
Thank you

Jerry Peck
09-19-2008, 07:36 PM
Is this makeup simply overkill or is there a potential issue here?
Thank you


"12 awg and 15 amp breaker-is this just overkill?"

Good for that electrician.

My guess will be reduced voltage drop issues on that house.

First, #12 AWG will not fit in the back stab holes, that alone accounts for most voltage drop issues, eliminate that back stabbing and most voltage drop issues go away.

The remaining voltage drop issues at then 'wire size', trying to run a 14 AWG too far. Switch to a #12 AWG and you can run a lot further without creating voltage drop issues based on wire size.

SMART ELECTRICIAN, that electrician.

He gets a big thumbs up!

Marc M
09-19-2008, 07:49 PM
I do appreciate your time, thanks.

Jim Robinson
09-20-2008, 01:22 PM
Supposedly here in my area, all home runs will be required to be #12 or larger starting back on June 1. I haven't met up with an electrician to confirm, but the guy who told me is usually correct in his statements.

Marc M
09-20-2008, 04:28 PM
your tha man...thanks for the input.

Jerry Peck
09-20-2008, 05:51 PM
Supposedly here in my area, all home runs will be required to be #12 or larger starting back on June 1. I haven't met up with an electrician to confirm, but the guy who told me is usually correct in his statements.


Jim,

What I would like to see would be #12 used for 15 amp home runs, you can use #14 from the home run on, but that should really be #12 too.

And I would like to see would be #10 used for 20 amp home runs, you can use #12 from the home run on, but that should really be #10 too. Of course, though, using #10 is going to really make it difficult to put devices in anything but deep boxes.

Jon Randolph
09-21-2008, 06:53 PM
I haven't came across that yet, but it would greatly reduce voltage drop. I have one question though....

The home is most likely wired with 15a receptical outlets off of that #12 conductor. Anyone having an issue with "nuisance" trips that knows anything about wire sizing (#12 = 20a) would assume that the 15a disconnect could simply be swapped out with a 20a to reduce the tripping but could allow for a fire hazard at individual outlets.

Is there any kind of marking/labeling required to help prevent attachment to a 20a disconnect?

Jon Randolph
09-21-2008, 07:07 PM
Nevermind, I found the answer. Yes, it is allowed provided that there are multiple receptical outlets on that circuit.

Ted Menelly
09-21-2008, 07:17 PM
I haven't came across that yet, but it would greatly reduce voltage drop. I have one question though....

The home is most likely wired with 15a receptical outlets off of that #12 conductor. Anyone having an issue with "nuisance" trips that knows anything about wire sizing (#12 = 20a) would assume that the 15a disconnect could simply be swapped out with a 20a to reduce the tripping but could allow for a fire hazard at individual outlets.

Is there any kind of marking/labeling required to help prevent attachment to a 20a disconnect?

When I was building or remodelling I never ran 14. Always 12

As Jerry said the stab the 14 in the back of the receptacles just doesn't cut it.

Jim Port
09-22-2008, 06:03 AM
Jim,

What I would like to see would be #12 used for 15 amp home runs, you can use #14 from the home run on, but that should really be #12 too.

And I would like to see would be #10 used for 20 amp home runs, you can use #12 from the home run on, but that should really be #10 too. Of course, though, using #10 is going to really make it difficult to put devices in anything but deep boxes.

What a waste of resources and money. Why would you take away 1/4 of the circuit capacity by installing a 15 amp breaker?

Installing upsized home runs could lead to more troubles down the road if someone where to change the breaker because of overload trips and does not know that the whole circuit cannot handle the now oversized overcurrent protection.

Voltage drop is an issue with long distances and heavy loads. I looked at my house, that I did not wire, the kitchen lighting was 1 circuit for 4 recessed at 65 watts and a table fixture that runs less than 200 watts. This is less than 500 watts on a circuit that can handle 1500. Bedroom circuits have a TV drawing 65 watts and an alarm clock totalling less than 100 per room.

I realize that not everyone lives they way I do nor are all homes wired as mine but come on lets be realistic.

Jim Robinson
09-22-2008, 07:38 AM
My pet peeve is that a lot of builders and manufacturers put a dedicated circuit in for the gas range. That is such an insignificant amount of power usage, it's crazy to use a dedicated circuit, in my opinion. It's running a clock and the self ignition device.

Corn Walker
09-22-2008, 08:10 AM
I've seen homeowners upsize the breaker to a 20A on old clad 15awg wire - the size of wire isn't going to have an impact on the ignorance of the homeowner. I'd rather they installed a larger breaker on 12awg wire than on 14. As an added benefit only the determined clueless will be able to back-stab a 15A receptacle with 12awg wire.

If you go to the big box store you'll find 14awg and 12awg wire priced with a negligible difference. 20A receptacles, on the other hand, are 4 times as expensive as 15A in those same stores. They cost about the same as GFCI receptacles.

I ran all 12awg cables in my home with the exception of a 14/3 switch leg I had to snake in a wall and a 10/3 cable to a location where the next homeowner is likely going to want to put an AC unit. Even though I had a gas range I still wired for electric (6/3) while the wall was open - which came in handy when I bought a dual-fuel range.

Jerry Peck
09-22-2008, 08:12 AM
What a waste of resources and money.

Waste of resources? Please explain that to me.

Waste of money? Please explain that to me too.

Do you drive a car? Get a bicycle, you will save money and gas.

Get real, not everyone wants to go back to the 1800s where you rode around on horses (dropping their poop in the street, that sure was healthy, wasn't it?).



Why would you take away 1/4 of the circuit capacity by installing a 15 amp breaker?

You aren't "taking away" anything ... well, you are "taking away" voltage drop, but you start with a 15 amp circuit, you end with a 15 amp circuit - what was "taken away"?


Installing upsized home runs could lead to more troubles down the road if someone where to change the breaker because of overload trips and does not know that the whole circuit cannot handle the now oversized overcurrent protection.

At least you are thinking there - good.

However, properly labeling of those conductors will avoid that.


Voltage drop is an issue with long distances and heavy loads.

Close.

Voltage drop issues are increased with long distances and heavy loads, but are present with any distance and any load.


I looked at my house, ...

I realize that not everyone lives they way I do

Glad you realize that.


but come on lets be realistic.

Yes, be realistic. There ARE homes with voltage drop problems. Your might too.

Take your bedroom, or the room furthest from the panel, you are operating your computer and entertainment center equipment, you are chilly, so you plug in a portable electric heater to take the chill out. You just created a voltage drop problem in that it is likely that your computer and entertainment equipment are operating in an under-voltage condition.

Who know what can go on where in what house.

To be as you are, I could say:

- if you own a pick up truck, you are wasting both money and energy resources

- if you own an SUV, you are wasting both money and energy resources

- if you own a second car, you are wasting both money and energy resources

- the list could go on, and on, and on ...

Yes, GET REAL!

OPEN YOUR EYES!

Corn Walker
09-22-2008, 08:33 AM
Voltage drop is an issue with long distances and heavy loads. I looked at my house, that I did not wire, the kitchen lighting was 1 circuit for 4 recessed at 65 watts and a table fixture that runs less than 200 watts. This is less than 500 watts on a circuit that can handle 1500. Bedroom circuits have a TV drawing 65 watts and an alarm clock totalling less than 100 per room.

I realize that not everyone lives they way I do nor are all homes wired as mine but come on lets be realistic.

What happens in the summer when the homeowner has AC units in the windows or in the winter when there are space heaters installed? (Those space heaters are often rated at 1875W by the way - do the math.) I'd feel much better knowing the over-current problems will be at the receptacles and circuit breakers rather than somewhere hidden in the wall.

Marcel Gratton
09-22-2008, 02:26 PM
Is this makeup simply overkill or is there a potential issue here?
Thank you

If the wiring is *AL* then it is not an overkill but rather required.

Jim Robinson
09-22-2008, 05:10 PM
Lowes: 100 feet 14-2 $38.90, 100 feet 12-2 is $57.00. 46% higher is not negligible in my book. Again, for one house, not that big of a deal. Nationwide that is a lot of money that could be spent on better insulation or roofing material that doesn't end up in the land fill after 15 years.

Off my soapbox now.

Jim Port
09-22-2008, 05:31 PM
What happens in the summer when the homeowner has AC units in the windows or in the winter when there are space heaters installed? (Those space heaters are often rated at 1875W by the way - do the math.) I'd feel much better knowing the over-current problems will be at the receptacles and circuit breakers rather than somewhere hidden in the wall.

Well if JP had his way you could not run anything else on the circuit because you installed a 15 amp breaker. At least if you had installed the 20 amp breaker with the 12 ga. wire you could still have other things working while the heater was on. Why do feel there would be a problem with properly sized wiring and overcurrent devices?

Even properly designed circuitry based on square footage requirements would be easy to overload given multiple heaters or window shakers on the same circuit that were not planned for. How would you propose to limit how many space heaters were in use at the same time? How many under-desk heaters should an office plan for when their circuits are laid out?

Jim Port
09-22-2008, 05:58 PM
Waste of resources - utilizing more than is required to do the job.

Waste of money- spending more than is required to do the job when a lesser amount will do. Someone just posted that upsizing the wire cost almost $20 more per 100 foot. Consider how much wire is actually used and the price adds up. The small addition I just finished took over a thousand foot. Thats $200 right there.

Reduction of capacity - lets see the wire is good for 20 amps and you only allow 3/4's of it to be used by installing the 15 amp breaker. Haven't taken math in a while but my 3rd grader says 15 is less than 20. Sounds kind of like buying a pickup with a 8 foot bed when you only need to carry the owners manual in the glove box.

Corn Walker
09-22-2008, 05:59 PM
Lowes: 100 feet 14-2 $38.90, 100 feet 12-2 is $57.00. 46% higher is not negligible in my book. Again, for one house, not that big of a deal. Nationwide that is a lot of money that could be spent on better insulation or roofing material that doesn't end up in the land fill after 15 years.

How much does it cost for an electrician to wire the house?

We're talking about wiring an entire house with 14/2 vs 12/2 (which, incidentally, is increasingly becoming the minimum size allowed). I don't know many electricians that buy their wire at Lowes but at my local supply shop a reel of 12/2 is about $190 more expensive than 14/2. Now the cost to install 1000' of cable... the $190 becomes a rounding error.

As for roof material, don't even get me started. My local shop has IKO 30yr architectural shingles for a whole $0.65 more per bundle than the 25yr 3 tab. There isn't a roof big enough for that to make a difference, and yet people still need to save money... What's that saying that starts with 'penny-wise...'?

Corn Walker
09-22-2008, 06:08 PM
Reduction of capacity - lets see the wire is good for 20 amps and you only allow 3/4's of it to be used by installing the 15 amp breaker. Haven't taken math in a while but my 3rd grader says 15 is less than 20. Sounds kind of like buying a pickup with a 8 foot bed when you only need to carry the owners manual in the glove box.

Not all 12awg runs are good for 20A. It depends on the length of the run and other derating factors that could get that 12awg wire rated down to 14A. But my neighbor with the bedroom space heater just might switch out the 15A circuit breaker with a 20A to prevent those "nuisance" trips. I'd sleep a lot better knowing his house was wired with 12awg wire rather than 14 back stabbed into a questionable receptacle.

Then again, my house had been wired with lamp cord and it didn't burn down. That's proof of something, isn't it?

Jerry Peck
09-22-2008, 06:24 PM
Lowes: 100 feet 14-2 $38.90, 100 feet 12-2 is $57.00. 46% higher is not negligible in my book. Again, for one house, not that big of a deal. Nationwide that is a lot of money that could be spent on better insulation or roofing material that doesn't end up in the land fill after 15 years.

Off my soapbox now.

So, ...

you can buy $10 sq yard carpet or $50 sq yard carpet, that's *500%*, not a measly old 46%.

Guess the entire country needs to *buy cheap carpet*???? :confused:

Somebody needs to quite watching everyone else's money and get real.

The cost for wiring a house is #12 copper instead of #14 copper is like spitting into the ocean when considered with all the other "upgrades" which have less meaningful long term affect on the house ... wait, there I go ... doing what I was accusing you of doing ... putting *my* valuation on someone else's valuation ... so what if they want to pay $50 per gallon of interior paint when they could have bought interior paint for $15 per gallon ... or that they want to spend $20,000 to have Venetian plaster in a *dining room* ... or that they want Ludowici roof tiles instead Monier roof tiles ...

Richard Mobley
09-26-2008, 01:15 PM
Question of clarification of terms, Is the “home runs” the wiring between the breaker and the first junction box or device?

Jim Port
09-26-2008, 04:09 PM
Question of clarification of terms, Is the “home runs” the wiring between the breaker and the first junction box or device?

Yes.

Now more characters so I can post.

Jerry Peck
09-26-2008, 04:49 PM
Jim,

That's why you will sometimes see me post: .Yes.

Because it makes 5.

Or

..No. or .No.. or even ..No.. (just to balance out the No with two dots on each side)

Got to find a way to play the game, you know.

:D