New kitchen project -- a few quetsions

[johneel]

OK, I'm redoing my kitchen in Massachusetts and pulled a permit. I have some questions though and have found this forum very helpful in the past. I have four GFCI receptacles on one counter at one side of the kitchen and four on the other counter. I am thinking of running two 12/3 wires from the main panel to three of the GFCIs on each circuit and then 12/2 wires to the last GFCI on the circuits. Is this right?. I am going to run a separate circuit for my refrigerator because my inspector suggested this for some reason. It's OK by me because I have a lot of space on my panel. Do I use 12/2 wire or 14/2? I think that's about it for now but I bet I'll be back with more questions before this project is done. Thank you in advance.
John

[piette]

What are trying to do with the 12-3?

What you can do is run 12-2 from the panel to the first recepticle, and then 12-2 to each one after that you want on the same circuit. You can put 4 recepticles on a kitchen circuit. So basically run a 12-2 from the panel to the recepticles on one countertop and a 12-2 from the panel to the recepticles on the other countertop. Then just run 12-2 through your circuits.

If you are going to try to split the circuits up even more, and use 12-3 to do it, it won't work. You can't put two GFCI's on one 12-3 wire, they will constantly trip each other, from the unbalance on the nuetral. So if you want smaller circuits, you have to do it with more 12-2 runs from the panel.

Also, use 12-2 for your fridge, you never know what fridge you may end up with in the future, and some of the new ones draw some big power.

Jeff

[BHD]

#12 will work for both a 20 amp breaker and a 15 amp breaker, if you run #14 only 15 amp breaker,

I on my own place have never ran #14, the stuff is very light wire, and if your having a breaker problems (not enough power) you can not up grade to 20 amp if you so desire to at a later time,

I would run #12 wire if it was mine, and leave the #14 in the store,

I am thinking of running two 12/3 wires from the main panel to three of the GFCIs on each circuit and then 12/2 wires to the last GFCI on the circuits

I am not following the question here, are you talking about a separate line to each GFIC?

The wire currently used to day, (saying it is 12 gage wire), has a white wire a black wire and a bare copper wire in it, and it is 12/2wG If you talking about the wire that has a black a red and white wire and a bare wire in it, that would 12 3wG, saying that the wires are a number 12 wire, and there are three wires for power, and one for ground,

and some GFCI (if I am remembering correctly do not do well with a shared neutral) 12/3, and sharing the white wire on two circuits, if that is your thought,
http://forums.jlconline.com/forums/showthread.php?t=26326
http://en.allexperts.com/q/Electrical-Wiring-Home-1734/Double-receptacle-circuit-shared.htm


most GFCI outlets will protect the out lets at are wired into it that are wired in down stream of it, one line to one side of the GFCI's and then tie on to that line down to the other outlets, (they if used the correct type of GFCI out let, will protect the following outlets), and then one line to the other side of the room,

unless you plan on having a dozen mixers going and a toaster oven and a waffle iron and coffee maker, all going at once I do not think you would need that many circuits, it will not hurt you any to have more than two circuits but unless you really plan on making the meter spin. but again it is better to have more than less, jsut in case,(at least if I am understood your statement and the wiring I am counting 5 circuits to the GFCI outlets, not counting the refrigerator,
EXAMPLE: the refrigerator is nice to have on a dedicated circuit as if you have an appliance on the same line and if for some reason it does pop the breaker, you my not take notice that the refrigerator is not functioning only that the toaster did not work and you knew the toaster was acting funny any way and you were sure you need a new toaster, and you running late any way so you check into latter when you get back home or maybe it is the next morning when you discover the refrigerator is not working. well by that time the refrigerator is hot and the ice cream is melted in the freezer and the milk is starting to sour,

[Badabing]

If you are going to try to split the circuits up even more, and use 12-3 to do it, it won't work. You can't put two GFCI's on one 12-3 wire, they will constantly trip each other, from the unbalance on the nuetral. So if you want smaller circuits, you have to do it with more 12-2 runs from the panel.


Why won't a 12/3 work? I use it all the time. You bring the 12/3 to the first outlet and from there make a splice with the neutrals from that box, and the one going to the next box, essentially the neutrals are both on the line side. The second circuit continues to the next box. You're not putting a neutral wire on the load side from the original box. Box 1 - 12/3, and 12/2 to next box. Red/black from 2 wire goes to 2nd box, black from 3 wire goes to line side of GFCI, ALL Whites splice together and get put on a line side of the GFCI. 2nd box black is on line side of GFCI, so is the white, if you continue adding outlets from either GFCI you would put those wires on the LOAD side of the GFCI.

[swoosh81]

Not to step on anyone's toes but your only allowed a max. of 2 recept. per circuit in a kitchen. No matter where they are in the kitchen. Each circuit also needs it's own neutral wire.
Also all counter top recept. need to be GFCI protected. Which means run a 12-2 to first box this wire will go on the line side then take 12-2 to the next box, this wire will attach to the first box GFCI on the load side. You then can use a standard recept. for the next box and it will be GFCI protected. Continue with the rest just like the first.

EDIT- My suggestion would be grab yourself a coppy of the new NEC book and read up.


Why won't a 12/3 work? I use it all the time. You bring the 12/3 to the first outlet and from there make a splice with the neutrals from that box, and the one going to the next box, essentially the neutrals are both on the line side. The second circuit continues to the next box. You're not putting a neutral wire on the load side from the original box. Box 1 - 12/3, and 12/2 to next box. Red/black from 2 wire goes to 2nd box, black from 3 wire goes to line side of GFCI, ALL Whites splice together and get put on a line side of the GFCI. 2nd box black is on line side of GFCI, so is the white, if you continue adding outlets from either GFCI you would put those wires on the LOAD side of the GFCI.

You sir need a NEC book bad before you burn someone's house down with that crap, or better yet go to a IEC school. If your interested I'll look one up in your area.

[DuckButter]

John, I'm from Mass..if you've pulled permits, the first thing the BLDG inspector will ask is "who's doing the plumbing & electrical?".
You are ok if you're only doing cosmetic, drywall, painting ...etc, but for either plumbing or electrical the inspector will ask.

[piette]

Not to step on anyone's toes but your only allowed a max. of 2 recept. per circuit in a kitchen. No matter where they are in the kitchen. Each circuit also needs it's own neutral wire.
Also all counter top recept. need to be GFCI protected. Which means run a 12-2 to first box this wire will go on the line side then take 12-2 to the next box, this wire will attach to the first box GFCI on the load side. You then can use a standard recept. for the next box and it will be GFCI protected. Continue with the rest just like the first.

Is what you are saying in the 2008 code cycle? It's not in any code cycle prior to 08, thats for certain. Wisconsin hasn't adopted the 08 cycle yet, so I haven't had a chance to dig into it yet, but as of the 05 cycle, their is no limitation on how many recepticles can be put on a kitchen circuit. Also their is no code that states the the kitchen circuits need their own nuetral either in the 05 or earlier NEC. I know many states revise the NEC for their own state code and limit the number of recepticles, but it isn't in the NEC prior to this newest code cycle.

Jeff

[piette]

Why won't a 12/3 work? I use it all the time. You bring the 12/3 to the first outlet and from there make a splice with the neutrals from that box, and the one going to the next box, essentially the neutrals are both on the line side. The second circuit continues to the next box. You're not putting a neutral wire on the load side from the original box. Box 1 - 12/3, and 12/2 to next box. Red/black from 2 wire goes to 2nd box, black from 3 wire goes to line side of GFCI, ALL Whites splice together and get put on a line side of the GFCI. 2nd box black is on line side of GFCI, so is the white, if you continue adding outlets from either GFCI you would put those wires on the LOAD side of the GFCI.

I have always had problems with putting GFCI's on balanced networks. They always trip each other. Maybe you are doing it in a diffrent way than I have. I quit doing it like that so long ago, that now I don't really even recall what I was doing;)

Not to mention that that combo would not work in a single gang device box, as you are over on cubic inches required for any 22 cu in box. I believe maybe it is P & S that makes a 22.5 cu. in. box which would work, but man that has got to be a bear to cram those wires in their plus a GFCI. Personally I just can't see recommending that with a GFCI in the box, maybe with a 2 gang box, or not using GFCI's.

Jeff

[bluecon]

It shouldn't work with the three wire system.
If you plugged into the second GFI the neutral will be carrying current and the hot on the first would not. I would expect this to trip the first GFI.

[johneel]

Good suggestions. I'm running 12/2 wire now and scrapped the 12/3 idea. A couple of points though: to Swoosh81, my wiring inspector signed off on my 4-receptacles-per-circuit plan; I've never heard fo limiting a circuit to 2 outlets. And DuckButter, my inspector said it was allright of me to do my own work but he asked that I call in an electrician to hook up all the wires to the panel. I can't do the plumbing. (I guess they have a better union!) Thanks all.

[DuckButter]

Good suggestions. I'm running 12/2 wire now and scrapped the 12/3 idea. A couple of points though: to Swoosh81, my wiring inspector signed off on my 4-receptacles-per-circuit plan; I've never heard fo limiting a circuit to 2 outlets. And DuckButter, my inspector said it was allright of me to do my own work but he asked that I call in an electrician to hook up all the wires to the panel. I can't do the plumbing. (I guess they have a better union!) Thanks all.

Just wanted to give ya the heads up, I've seen jobs were the homeowner completed the work, then the inspector makes 'em hire a plumber to rip it out and redo...plumbers ain't cheap when they have to remove & redo the work.

[Badabing]

You sir need a NEC book bad before you burn someone's house down with that crap, or better yet go to a IEC school. If your interested I'll look one up in your area.

If you like, I'll buy YOU the code book, it says you need 2 CIRCUITS, not 2 OUTLETS per circuit. You can put as many outlets as you like on the cirucit, but you neeed ATLEAST 2. To help you out, it's ARTICLE 210.11 (C) (1)

As for 3 wire circuits, not sure how anyone else is having a problem, probably not wiring them correctly.

[QROKING]

There is no problem running a 12-3 to a kitchen JB and splitting off into two separate circuits protected by one GFCI for each circuit. The GFCI's for each circuit will NOT interfere with each other if you wire them correctly. Whoever said they won't work does not know what they are talking about. There has been alot of misconceptions by some on this post. And I NEVER heard that you can only have 2 outlets on a kitchen branch circuit. All kitchen circuit outlets must be GFCI'ed (unless they meet some special criteria) and the wiring for outlets must be 20A #12 wire) and a minimum of 2 20A circuits. Lighting is a different sotry. Gets your facts straight.

[piette]

There is no problem running a 12-3 to a kitchen JB and splitting off into two separate circuits protected by one GFCI for each circuit. The GFCI's for each circuit will NOT interfere with each other if you wire them correctly. Whoever said they won't work does not know what they are talking about. There has been alot of misconceptions by some on this post. And I NEVER heard that you can only have 2 outlets on a kitchen branch circuit. All kitchen circuit outlets must be GFCI'ed (unless they meet some special criteria) and the wiring for outlets must be 20A #12 wire) and a minimum of 2 20A circuits. Lighting is a different sotry. Gets your facts straight.

Ok, so let's say you are right and you can keep the two GFI's from tripping each other, how do you keep from having a potential of 40 amps on a #12 wire? In a kitchen their is as much potential to put maximum amperage on a circuit as their is in a garage, so how do you keep 40 amps off that nuetral then? Do you put in 15 amp breakers or do explain to the customer that the wires are not rated for the amount of amperage they could very likely put on them and ask them to limit what they plug in or what?

I'm not trying to be a smart ***, I am asking a serious question. Their is very good probability for that nuetral to carry 40 amps at any time.

Jeff

[bluecon]

Ok, so let's say you are right and you can keep the two GFI's from tripping each other, how do you keep from having a potential of 40 amps on a #12 wire? In a kitchen their is as much potential to put maximum amperage on a circuit as their is in a garage, so how do you keep 40 amps off that nuetral then? Do you put in 15 amp breakers or do explain to the customer that the wires are not rated for the amount of amperage they could very likely put on them and ask them to limit what they plug in or what?

I'm not trying to be a smart ***, I am asking a serious question. Their is very good probability for that nuetral to carry 40 amps at any time.

Jeff
You feed the 3 wire from a double pole breaker and the opposite 120v phases will take care of that. You won't run 40a in the neutral.

[piette]

You feed the 3 wire from a double pole breaker and the opposite 120v phases will take care of that. You won't run 40a in the neutral.

Yeah now that you say that, I know where I got the thought from, because it actually did happen.

I was recently sent out to a restraunt with a 3 phase service and someone had pulled a multi wire branch circuit in to the kitchen for the prep counter recepticles and had three phases sharing a nuetral. That one the nuetral did burn up, but it had a load of like 38 on a #12.

You are correct, with only two phases sharing the nuetral, the maximum unbalance could only be 20 amps. I stand corrected. I have been doing way to much 3 phase only lately. I need to go back to my roots and do some houses again.;)

Jeff

[QROKING]

Mind you, that when you do use a 2 circuit 3 wire feed, you WON'T be able to use GFCI breakers in the panel or else they will conflict, but you can use separate GFI outlets to protect the individual circuits once they have been split off. Now If I am not mistaken with 3 phase power, you CAN run all 3 phases off of one neutral and the nuetral will not be overloaded. In a 3 phases system if all 3 pahses are drawing current the load on the nuetral will be the unbalanced load of all 3 phases, in which case the nuetral load will never be higher than any one maximum current. So lets say you have a 3 phase system, you have a 20 amp breaker on each 3 phase hot leg and only one nuetral, if all 3 phases are drawing 20 amps the current on the nuetral is 0. If 2 phases are 5 amps and one is drawing 20 amps the nuetral is carrying only 10 amps. As proof to this, if you look at a 3 phase panel box the nuetral is never bigger than any of the line voltage wires because the current on the nuetral will never be more than the differnce in current in any of the 3 phases at any given time. Check that out

[QROKING]

I want ot correct my above statement by saying that though it is true that you can run all 3 phases on one nuetral and not overload the nuetral on a 3 phase system to nuetral loads, it is not as I said above by simply adding and subtracting the loads. Though it is true that if all 3 pahses were carrying 20 amps the current in the nuetral is 0, if all 3 phases are drawing current the resultant current in the nuetral is not simple addition subtraction as I mentioned before, but rather it is vector anaylasis using trig that calculates the current in the neutral, but the fact still remains that the current in the nuetral will not be higher than the highest current carrying conductor, in which case the nuetral will NOT become overloaded. Sorry for the mistake, but I have clarified it here. My apologies.