New Circuits


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Old 03-07-04, 03:29 PM
stevejr
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New Circuits

I'm in the process of remodeling a bathroom and the whirlpool tub requires two 15amp GFCI circuits - 1 each for the pump and heater. Should I run two lengths of 12/2 grounded or will a single run of 12/3 grounded (two hot, one return and one ground) allow me to service both outlets?
 
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Old 03-07-04, 06:49 PM
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Running a 3-wire cable will probably be the easiest thing to do but you will need a two pole GFI breaker. You cannot use two single pole GFI breakers in this case. It's not a big deal since you need two anyway and the cost is not much different.

The other option is to use faceless GFI's near the unit but this is more of a hassle than it's worth IMO.

Why 12/2? If the circuits only need to be 15 amp 14/2 or 14/3 is fine unless the distance is around 100 feet or more. You could also use 12 wire on 20 amp breakers unless the manufacturer specifically states 15 amp.

In a residence the distances requiring up sizing wire a rarely met. I really do not like mixing wire sizes or straying from the norm of 14 wire on a 15 amp and 12 wire on a 20 amp. It only serves to add confusion later on.
 
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Old 03-07-04, 07:10 PM
R
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I would run a multiwire circuit of 12-3. I would run 12-3 even though 14-3 would work, just in case in the future a replacement tub needs a 20 amp circuit.
 
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Old 03-07-04, 07:55 PM
stevejr
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The run from the box to the outlet is pushing 70 feet so, with the added advantage of future expansion I'll probably go with the 14 guage as planned. Thanks to both for your suggestions!
 
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Old 03-07-04, 08:03 PM
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Huh? You do realize that 12-gauge wire is heavier than 14-gauge wire, right?
 
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Old 03-08-04, 09:25 AM
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Because of the lenth of the run and one of the loads is a motor, dismiss any consideration of using #14 wire. A motor will draw 300% of the normal full-load current when starting.

I advise two seperate 12/2 cables for the 2 Branch-Circuits, each protected by a GFI C-B. A problem in one circuit won't affect the other circuit, and if such occurs, you'll know exactly where to look.

You also will have "flexibilty" for and needed circuit modifications. For example, in the future you could convert either circuit from 120 volts to 220 volts. This is a distict possibility with motor-circuits because many motors are wound for "dual-voltage" connections.

Good Luck & Enjoy the Experience!!!!!!!!!!
 
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Old 03-08-04, 04:31 PM
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PATTBAA,

I don't want to question your knowlege but what does the start up current have to do with it? All breakers have this taken into consideration. If you size a circuit to the running amps you are fine. The breaker will not trip. As far as the wire is concerned, this current is momentary. It's not like it runs at this number for any time at all.

Like I said in my post, running 12 is fine. I just personally do not like to put 12 on a 15 amp unless it is absolutely necesary. And in that case I mark the wire as to why it is on a non-standard breaker.
 
  #8  
Old 03-08-04, 08:09 PM
stevejr
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Hey All,
Sorry for the confusion. What I meant to say is that I'll be using the 12/3 as originally planned... not 14/3. That is what the manufacturer recommends and it squares with everything you've all told me.

I'm still inclined to use a single 12/3 run rather than two 12/2 runs. Cost isn't an issue but I'm going to have to snake through a lot of tight places and I figure the single round cable will be easier to work with.

The only other question is on the GFCIs themselves All I've seen at the big orange box is two pole models and the man in the orange vest told me that can use two of these in a double box. He told me I can split the common and the ground while running a hot to each. I've gotten allot of bad advise from people wearing the same outfit... can I trust this one???

Steve
 
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Old 03-08-04, 09:24 PM
ltngbolt
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Maybe I am misunderstanding what you are attempting to do but if you plan on running a 3 wire cable and then putting it on a 220 volt GFI circuit breaker in the panel for two different loads it is not going to work nor is it legal. What you can do in the case of the 3 wire cable is put the GFI in the form of deadfronts or receptacles somewhere up near the tub to protect each circuit individually.

If I misunderstood my apologies....it's late and I am tired
 
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Old 03-08-04, 09:48 PM
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Itngbolt, I'm not sure what you mean when you say "it is not going to work nor is it legal." 12/3 on a double-pole GFCI breaker will be both functional and legal.

Nevertheless, I agree with your suggestion to use two GFCIs near the tub, but only because it will cost less than the double-pole GFCI breaker.
 
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Old 03-09-04, 05:38 AM
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If you use 12-3 then you should use a double pole breaker, even though it may not be specifically required. If you use two separate runs of 12-2 then you can use two separate single pole breakers.

If you have the GFCI at the breakers (either single or double pole) then you can use regular receptacles at the tub.

If you use non-GFCI breaker(s) then you need to add the GFCI protection at the other end. There are several ways to do this. You can do so with 2 normal GFCI receptacle outlets. You can do so with 2 faceless GFCIs and then one or two normal receptacle outlets.

If you run a multiwire circuit and have the GFCIs at the tub, you connect as follows: One hot to each line side hot on the GFCI. The neutral is pigtailed to each line side neutral on the GFCIs. After the GFCIs (if you use faceless ones) then you need two separate 12-2 circuits to the outlets from the load side of the GFCIs.

Personally I prefer GFCIs to be at the point of use, making a reset easier. However not everyone agrees with that.
 
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Old 03-09-04, 08:19 AM
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John Nelson;
You state " 12/3 on a 2-pole GFI C-B is fuctional"

One could conclude from this observation that the obvious current un-balance inherent in such a circuit will have no effect on the operation of the GFI C-B.

With 8 amps in one pole and 10 amps in the other pole, how does the GFI C-B "detect" a current-leakage to Ground.?

Cheers, PATTBAA
 
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Old 03-09-04, 08:50 AM
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A double-pole GFCI breaker has three connections, one for each hot and one for the neutral. The internal electronics do a three-way current comparison. A GFCI receptacle only does a two-way current comparison.
 
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Old 03-09-04, 09:33 AM
stevejr
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Hey guys,
I hadn't thought about using a GFCI breaker in the service panel but in this case it would be the best solution. The outlets will be mounted inside the tub enclosure and will only be accesible through the service pannel. If the breaker does trip it will be much simpler to reset at the source. However, I don't think HD stocks 15amp (manufacturer recommended) two pole GFCI breakers so I'll have to do a little detective work to find one.

While on the subject of the service pannel... right now I don't have any open slots. There is a 40amp two pole breaker that was supplying the electric cooktop but we switched to gas and don't intend to go back.

My original plan was two switch out the 40amp breaker with a 15amp and leave the expandablilty issue for the next home owner. But, now I'm wondering if I should use the existing 40amp breaker to supply a subpannel and run the tub circuits from there. Assuming that's doable, would it be a project you would recommend for a DIYer?
Steve
 
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Old 03-09-04, 10:10 AM
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If this is the last electrical project you will do, then replacing the 40-amp with a 15-amp is certainly the easiest. If you think you'll need more space, then put in the subpanel. However, don't feel compelled to put in a 40-amp subpanel just because you happen to have a 40-amp breaker there. If you go to all the trouble of a subpanel, make it at least a 60-amp subpanel.

Installing a subpanel, especially one in the same building as the main panel, is certainly within the capabilities of an experienced DIYer. There are a lot of rules to follow, but these rules are posted all over the web, and have been posted in this forum a few hundred times too.
 
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Old 03-09-04, 12:29 PM
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John;

Please know that your concise but clear expalnation of how a 2-pole GFI C-B "functions' is much appreciated, and I'm sure the info will be useful to all those who have "viewed" this posting.


"And gladly would he learn, and gladly teach"
 
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Old 03-09-04, 04:15 PM
ltngbolt
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John, you are always on the mark so I don't doubt your right. Could you point me to the section of the code that allows 2 different loads to be controlled by a 2 pole GFCI circuit breaker.
Thank you in advance.
 
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Old 03-09-04, 04:54 PM
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Regardless of the fact that it's a GFCB it's still a basic multi-wire circuit. 210.4
 
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Old 03-09-04, 06:47 PM
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Itngbolt, this is common as dirt--not at all unusual. It's called a "multiwire circuit." Start in article 100 and look up the definition of "Branch circuit, multiwire". Then look up that same term in the index. It will point you to 210.4 and a few other places. But 210.4 tells you most of what you need to know.

One of the odd things about multiwire circuits is that code allows you to treat this as either one circuit or two, whichever is to your advantage. For example, you can treat it as one circuit when supplying an outbuilding (because code doesn't permit you to run two circuits to an outbuilding). And you can treat it as two circuits when satisfying the requirement for two small appliance circuits. Pretty cool.

But all this comes with a caveat. If you don't know what you're doing, it can be hazardous. These points must be considered before running a multiwire circuit;[list=1][*]Make sure the two hots are on different power legs, or the neutral will catch fire.[*]Make sure you pigtail the neutral at any receptacle.[*]Don't try to connect a shared neutral to the load side of a GFCI.[*]Use a double-pole breaker if using both hots on any one device.[/list=1]If you're not 100% sure what each of these mean, then please do not install a multiwire circuit. For most applications, I do not recommend a multiwire circuit for DIYers. Having said that stevejr has a good reason to use one--poor access. Other good reasons are long distances (where you are trying to control voltage drop) and providing power to an outbuilding (as previously discussed).
 
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Old 03-09-04, 07:02 PM
ltngbolt
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Thanks so much for the info John.
Truth is I am not a DIY I am a licensed electrician in the business for over 25 years. I am a little embarrassed to say I have never seen this practice used. I am not sure what the reason is but in this area it must not be practiced very often. I have been in thousands of residences over the years and never once ran across this application.

Thanks for the eye opener
 
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Old 03-09-04, 07:06 PM
ltngbolt
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Just to clarify it wasn't the multi wire circuit that puzzled me it was the use of a 2 pole circuit breaker gfi
 
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Old 03-09-04, 07:20 PM
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I've done this when the customer doesn't want those "ugly GFI's" on their new granite counter.
 
 

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