# Rewiring House DIY Info



## Joelkbish (Oct 27, 2019)

Hello I been in the process of rewiring my house have half the house rewired i asked people if I should rewire it in all 12 guage romex wire or 14 some people said 14 but most people say 12 that way you can upgrade breakers to 20amps and not have to tear out walls to upgrade the wire in the future plus more fire residence an durable compared to 14 what our your guys thoughts it safer or not safe matter or not matter?


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## pjones (Oct 27, 2019)

Well, you should be an electrician if you are doing this work so you would know how to calculate voltage drop based on the length of run that you are installing and size your wires based on that. It’s hard to go wrong by running larger wires than required. The problems start when you start assuming that a wire will cary a specific amperage without factoring in voltage drop, temperature, or the connected load.


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## afjes_2016 (Oct 27, 2019)

Actually having wired half your house already and now asking for confirmation of wire rating and reasoning for such is a bit late in this case considering you should have been checking on code requirements as you went along.

Yes, 12 gauge can handle a 20amp breaker whereas 14 can only handle 15amp breaker. The issue is more than that though.

In certain areas of the home 12 gauge is required mainly because the NEC dictates it in such a sense for example SAC in the kitchen, dining room etc areas. In this case it has to be a 20amp circuit which dictates a 12 gauge conductor. 

There are many more examples that can be stated here but again most of which you should have learned by checking the NEC requirements along with your AHJ (local code office) for their requirements.

If a particular circuit is permitted to use a 15amp circuit there really is no harm in using a 20amp circuit utilizing 12 gauge conductors. It is a bit more costly and harder to work with but it can have its benefits.

I hope you plan on having your wiring inspected.


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## JoeD (Oct 27, 2019)

If you are using 15 amp breakers then you should use #14. If you want 20 amp then use #12 and install 20 amp breakers.
If it was my house I would be using #14 and adding more circuits if I thought the load was going to be too much in one area.
There are some required 20 amp circuits that will need to be installed no matter what; kitchen counter and bathrooms.


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## Joelkbish (Oct 27, 2019)

Yes I called code efforcemmt gave me the OK I had middle agency also inspection inspect my wiring he said looked nice was on the right track just need ground pig tails in my junction boxes which I did he passed it ill have them come again when I rewire the upper part of the house when I bought my house they ha nothing grounded all old romex in basement without grounds 3 bedrooms kitchen lights bathroom socket lights all on a 15amp breaker knob and tube and the whole attic is filled with knob buried in a foot of blown in insulation in the attic removing all of it adding new why I did a ton of research on wiring just wanted a clear answer if is OK to do so some agree some don't hear 14 is more prone to voltage drops were 12 won't 14 more likely to break causing fire were 12 won't 

Here's pics of before after wire and inspection paper

https://photos.app.goo.gl/Fj3VtheV2deUc34CA
https://photos.app.goo.gl/hBEETwoXWJqc2wpr6
https://photos.app.goo.gl/B5d5X43usNXBb62M7
https://photos.app.goo.gl/bPKDYsVUGyuAjP1m6
https://photos.app.goo.gl/oHAi2z4N8ebDk8SCA


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## cdestuck (Oct 27, 2019)

Hey pal, Not here to be rude, but when you finish typing what is a sentence, please put a period.   ''.''    Ys, one of those. Makes it a ton easier for the folks your asking to reply to rad and understand your post.   Tks


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## Michael Armstrong (Oct 27, 2019)

A conductor isn't "prone" to a voltage drop -- all practical conductors have a voltage drop. The magnitude of the drop depends on the current flowing (I) and the resistance (R) of the conductor, and is equal to I*R.  A (physically) larger wire size (e.g., AWG 12 vs AWG 14) has a smaller resistance per unit length, and so exhibits a smaller voltage drop. For example, over a 100' length of cable, an AWG14 cable carrying 10 amps will exhibit a voltage drop of 5.05V. Use an AWG12 cable instead, and the voltage drop is only 3.18V. 

Excessive voltage drop can cause loss of efficiency in operation of light, motors and appliances. This could result in lights that are dim and motors or appliances whose life is shortened. So it is important to use the right gauge of wire when running wires for a long distance. 

There's also a safety issue: The voltage that's  "dropped" is actually used to push the current through the conductor, and in the process generates heat, the amount of heat roughly proportional to the square of the current. The more current, the more heat, and too much heat can be a fire hazard. Cables are sized and matched with circuit breakers so that the breaker will trip before allowing enough current to generate a dangerous amount of heat if everything is installed correctly. 

So, if you try to run a big motor, say, on a 14AWG circuit protected by a 15A breaker, the breaker may trip at 15A. You might the up the CB to 20A or more just to allow your motor to run, but 2 bad things happen: 1) the voltage drop may result in a voltage too low to operate the motor properly, and 2) the excess current in the cable might result in a fire. For an overly dramatic demonstration of this, see .


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## afjes_2016 (Oct 28, 2019)

"OK to do so some agree some don't hear 14 is more prone to voltage drops were 12 won't 14 more likely to break causing fire were 12 won't"

Not quite sure where you read this but any gauge conductor is prone to voltage drop compared to a conductor of a smaller gauge. That's just physics at work. Voltage drop does not really come into play until you are talking a length of 100 feet plus.

Don't know where you read that a 12 gauge conductor won't cause a fire as easily as a 14 gauge conductor. Given the right circumstances both have just as much chance of causing a fire in a residential home as the other.
Example: Placing a 30amp breaker on a 20amp circuit (wired with 12 gauge). I have seen this in homes before. The homeowner figured placing a 30amp breaker on the circuit will lessen the times the breaker trips - no, not placing such a heavy load on which the circuit is rated for will lessen the chances of the breaker tripping.

Second vote here also - easier to read your posts if you do use some punctuation.


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## Joelkbish (Oct 28, 2019)

After getting all your guys advice I will wire the sockets with 12g wire 14g for lights. A lot of this stuff I read on the internet guess you can't believe everything you read. So i will stick to what you guys are telling me vs what some others may say! Thanks for all the replys.


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## JoeD (Oct 28, 2019)

Do not mix gauges on the same circuit. It is not against code but it is not good practice. If someone later on sees #12 on a circuit not knowing there is also #14 they might think it is OK to change the breaker to 20 amp from 15.


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## Joelkbish (Oct 28, 2019)

Yea almost did that with my furnace they had 12g wire hooked onto a 15amp breaker. I almost put a 20 in because the furnace says it requires a 20 Amp for the furnace but the wires to the sump pump are a smaller gauge  also hard wired in. It was a good thing i noticed!


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## Eddie_T (Oct 28, 2019)

Another thing to remember is that the lower cost receptacles are 15 amp, or they were when I wired my house. I used 12AWG wire and 20 amp breakers but I don't put a 20 amp load on a single receptacle.

I make a point if I replace a receptacle to upgrade to a 20 amp receptacle. I don't know if the current current code addresses this but my wiring passed in the 70s.


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## Joelkbish (Oct 30, 2019)

Here's a perfect example of why I'm asking this question to more tips and advice. This guy wired this whole house in 12g wire in this video in 1994. He was doing a video showing how neat, nicely the wires are done from back then when he was younger. So I could not help my self but ask hey are those a mixture of 14 and 12 or 14g because the wire coating was white thought is may have been 14 because 14 is normally white. Well he said he never uses 14 for his rewires even lighting! His wiring to me looks very nice here is the vid link and his reply! 

https://photos.app.goo.gl/NwmoggtQ5LjDvdvCA


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## Joelkbish (Oct 30, 2019)

Hi I have another question.
On my neutral ground bus bar this is one solid bar for both neutrals and ground wires. They say it is perfectly normal to only have one bus bar. Just just make sure your neutrals are separate from your ground wires on the bus bar (so the neutral wire has its own screw by itself) ! I read you can double up on ground wires put more then one together on one screw anyone done this before? I also noticed I have big and little screws on my bus bar is there a reason for that or does it not matter here is a pic below. Thanks

https://photos.app.goo.gl/WUS7FpFFPBhxar6s6


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## pjones (Oct 31, 2019)

I’ve seen it too many times where two wires are secured into a terminal and once it’s fastened down only one of the two wires are secured. Whenever possible use one wire per terminal.


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## JoeD (Oct 31, 2019)

You can not rely on the colour of the cable jacket to indicate the gauge. There is no code for that. It is a recent manufacturer practice to colour the outer jacket by gauge and I don't think they all do it.


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## Eddie_T (Oct 31, 2019)

I wired my house in the 70s using 12 AWG for all except a 14 AWG overhead lighting circuit and I think one 10 AWG for a heating circuit. The 12 AWG and 14 AWG have white sheaths, the 10AWG didn't have a sheath it was brown direct burial cable as there was a copper shortage and that was all that was available.


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## Joelkbish (Nov 10, 2019)

Eddie_T said:


> I wired my house in the 70s using 12 AWG for all except a 14 AWG overhead lighting circuit and I think one 10 AWG for a heating circuit. The 12 AWG and 14 AWG have white sheaths, the 10AWG didn't have a sheath it was brown direct burial cable as there was a copper shortage and that was all that was available.




Check out this web page that has a some good info on installing larger guage wire in your home. It also has tons of benefits to energy costs and less risk of fire. That's the main reason behind why i was wondering about installing all 12g wire. Why i can't understand why someone would choose 14g over 12g other then it being easier to work with!

https://electricatoz.com/benefits-of-bigger-wire-for-your-power-bill-and-home/


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## Eddie_T (Nov 10, 2019)

Joelkbish said:


> Check out this web page that has a some good info on installing larger guage wire in your home. It also has tons of benefits to energy costs and less risk of fire. That's the main reason behind why i was wondering about installing all 12g wire. Why i can't understand why someone would choose 14g over 12g other then it being easier to work with!
> 
> https://electricatoz.com/benefits-of-bigger-wire-for-your-power-bill-and-home/


You're right. I only used 14g for overhead lighting as it had few lights on the circuit and little chance of overloading. I used 10g on a 17a heater circuit for the reasons you cite.


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## afjes_2016 (Nov 11, 2019)

Yes, I took a look at this article you gave a link to here.

Honestly, half way through the first paragraph, mainly when I reached this sentence -

"However, you can increase the energy efficiency of your home by asking your electrician to use a larger gauge wire than the minimum recommended size."

I realized this was not written by someone who really knows what they are talking about. Seems more to me that this person took clips of what they read on the Internet elsewhere and put it together in their own way.

Stated -
"If you have an outlet in your home wired with 15 amp wire, and you plug in a 20-amp appliance, you’re asking your wiring to deliver more current than its capacity rating."
I can't think of any time that I saw a 20-amp rated appliance used in a home other than maybe an a high capacity "UPS". If you take five 6-amp appliances and plug them in and run them all at the same time on one 20amp circuit you are still going to trip the breaker.

Persons with formal education in electrical theory and being trained in the trade of "Electrician" will look at this article and can pick it apart. 

Wiring your home - other than where required to have a 20amp circuit such as a SAC, laundry circuit etc you can run all 15amp circuits (14 gauge) and you can put 25 receptacles on the one circuit or you can put only one receptacle on the circuit. The number of receptacles are meaningless when not being used.

Having a 20amp circuit with 12 gauge wire - run a vacuum cleaner and hair blow dryer on the same circuit at the same time and dimes to donuts you will trip the breaker.


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## Eddie_T (Nov 11, 2019)

I used   12AWG just to cut voltage drop as some runs were 60 feet. I thought about ring feeding using 2 breakers but couldn't decipher the code to determine if it was legal.


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## afjes_2016 (Nov 12, 2019)

Voltage drop really does not come into play until about 100 feet. Many times also in a home using a sub panel in an area far from the main panel will reduce the possible need of figuring voltage drop; that's the handy dandy reason for the sub panels  

May I please ask what "ring feeding" means? It may be an old "trade term" that I have not heard of.


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## JoeD (Nov 12, 2019)

The term ring circuit is more common in UK. It is a circuit that is fed from both ends in a loop or ring. I do not think they are permitted here.


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## Eddie_T (Nov 12, 2019)

I'll give an example of voltage drop. I rented a Levitt home in Bowie, MD which was wired with 12AWG aluminum. The wiring approach was cleverly designed to save wire so layout in a Cape Cod home wasn't immediately obvious to the resident.

I was watching TV  and the picture shrank in from the edges periodically. Puzzled I found the breaker got out my VOM and found all the receptacles on that branch. It turned out that my wife had left the iron on in a BR which was cycling and affecting the TV in the LR on the same circuit.

My brother down the street had a similar problem, when he started his table saw the fluorescent lights in his garage started flickering. So when I wired my house all receptacles are on 12AWG copper branches and the garage receptacles are on 10AWG copper and I have never experienced a problem.

I didn't realize that my receptacles were 15A until one that I was using for a quartz heater failed. The heater was 1500W but the receptacle got hot enough to affect the tension of the contacts over time. I replaced it with a 20A receptacle.


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## ShellbackBill (Nov 12, 2019)

Just use 12 gauge and 20 amp parts.
If you are doing the work yourself, the added cost is minimal.
 There is no downside other than cost to doing this.

Unless you house is HUGE and has very long wire runs you are good.


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## Jeff Handy (Nov 20, 2019)

afjes_2016 said:


> Yes, I took a look at this article you gave a link to here.
> 
> Honestly, half way through the first paragraph, mainly when I reached this sentence -
> 
> ...


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## Jeff Handy (Nov 20, 2019)

A 20 amp appliance has a plug with the prongs in a different layout, so it will not be able to be inserted into a 15 amp receptacle. 
Unless someone changes the plug. 

20 amp household appliances are not as common as years ago. 
Motors are more efficient, for one thing 

But back then, things like waffle irons or other devices that generated lots of heat sometimes needed a 20 amp circuit and outlet. 

Elsewhere in the house, many circuits that power something with a big motor are required to have 20 amp capacity, because the motor draws higher current when starting up. 
Sump pumps, sewage pumps, whole house vacuum, some furnaces, etc. 

And electric heaters like for a garage, or circuits to a workshop for big power tools.


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## Jeff Handy (Nov 20, 2019)

That ring feeding type of wiring is commonly used in 12 volt dc landscape lighting layouts. 

So the farthest fixture does not get starved for voltage. 

Although that is less of a problem now, with LED  lights taking over from halogen.


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## Eddie_T (Nov 20, 2019)

Thanks Jeff, I was incorrect in stating that I replaced a failed 15A receptacle with a 20A receptacle. It turns out that I just replaced a 59¢ 15A receptacle with a higher quality 15A receptacle.  It's good to know that the use of 15A receptacles is not a problem.


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