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Making a lighting circuit a 3 way

matt_i

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Some background, I am trying to finish adding a new shop to an existing shop. I have some reasonably high powered lighting (1kW) on the "old" side which often gets left on while I'm working in the "new" side. When I remember, and ultimately trying to conserve energy I have to walk all the way back thru to the single pole switch and turn it off.

It occurred to me to try to work smarter and not harder, and make this a 3 way circuit.

So I started making some circuit drawings to try to minimize the damage as the single pole switch for this circuit is set in drywall, with some access from above.

Drawing #1 is the original circuit, simple switch and a bulb to represent the lighting load.

Drawing #2 involves running a 14-3 "traveler" wire between the boxes, and then a 14-2 wire to carry the common-hot back to the bulb, so 2 wires would have to be run.

After thinking about the circuit for awhile, and trying to simplify, the redundancy is in the neutral wire which goes all the way over on the traveler 14-3 above and then comes back on the 14-2 above. If the neutral could just stay at the original box location, then the common-hot is the only one that has to come back. Essentially I could perform this function with a single 14-3 (enter Drawing #3). Functional problem solved, wire minimization = great.

But I have a new problem in that a 14-3 doesn't come in a black-red-orange. ..or any other 3rd color for as far as I know. Do I enter the extremely perilous territory of "phase-taping" a #14 awg, or do I just use Drawing #2, or is there something else easy that I'm missing. Thanks for your input.

Grounds eliminated for simplicity. They are there and present as normally used.

 
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akpingel

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What if you put the second switch in series with the first, so that you only need to run 2 wire? Downside would be that when you leave, you need to turn the light back on locally, then again shut it off at the main switch.
 

Wirepuller

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If you have the feed and load in the existing switch box run a 14/3 from the single pole to wherever you want the new switch to be. In the new box tie the white to common screw on the switch black and red are your travelers. In the existing box splice the white of the new 3 wire to the black of the feed wire and tuck them in the box, Put the black of the load wire to common of the switch and black and red of the 3 wire are your travelers.


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matt_i

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If you have the feed and load in the existing switch box run a 14/3 from the single pole to wherever you want the new switch to be. In the new box tie the white to common screw on the switch black and red are your travelers. In the existing box splice the white of the new 3 wire to the black of the feed wire and tuck them in the box, Put the black of the load wire to common of the switch and black and red of the 3 wire are your travelers.


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I think that's my "Drawing 3" just without phase-taping the neutral....connect white to common.

I know what I plan to do :D (there are two lighting circuits in the same box, iow 2 different 3-way travellers to be added). I was trying to challenge myself to "not phase-tape any conductors" and see what the actual outcome would be. Its a lot of extra work!
 

dogdog

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#2 is better, at least you have neutral everywhere .
#3 is just a pain to implemented and troubleshoot when you get senile, so you are going to run 1 wire (the orange one) from the remote switch to lights if you go by #3....???? and run 1 neutral wire to the lights from the other to the light..... some how that doesn't make sense but it works.
 
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Radix2

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#3 is the normal way to do it...your concern about taping the white wire is "odd"

Under the new code that requires a neutral in every box I suppose it is not allowed, but who's going to complain...

The ultimate way to do this (the garage journal way) is to do #3 but run two 14-2 or find some 14-4 or 14-2-2 NM wire and send the neutral over to the new location.

If you are big on smart switches everywhere you might consider it, but I can't see the value myself....
 
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matt_i

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Going with Pathway #2, I just phase-taped the neutrals, phase taped the perimeter of the switches the same color, phase taped the exterior of the wires as soon as they break into the open attics for someone in the future to help them recognize what is up.
 

jim111

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tx
#3 is the normal way to do it...your concern about taping the white wire is "odd"

Under the new code that requires a neutral in every box I suppose it is not allowed, but who's going to complain...

The ultimate way to do this (the garage journal way) is to do #3 but run two 14-2 or find some 14-4 or 14-2-2 NM wire and send the neutral over to the new location.

If you are big on smart switches everywhere you might consider it, but I can't see the value myself....

Code doesn't require the neutral at the second switch of a three-way setup if they are in the same room. Just run drawing #3 with 3 wire cable and be done with it
 

Matt Matt

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Ontario
I would like to clarify... is your original power coming into the first switch? Or to the bulb? I always like to run the three wire between two switches when possible. I don't have a problem with labelling the white. And there is no code requirement besides "labelling the white wire as not common". You can use black tape or red tape or shrink of the same colors. Personally I would choose number two. Number two does not require any tape as common is passed right through to bulb. Is number one your original wiring??? If so I'd, probably Number three and label the white as anything but blue.

The more think about this, the more I like this question you proposed.:beer:
 
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prostreetamx

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Las Vegas
We did this all the time on houses where a 3 way is somewhere that makes it inconvenient
to run the power or switch leg to a second location such as at stairs or even long pony walls. In Nevada we called this a California 3-way. We always sent away the power leg over the white wire that we wrapped around the travelers at the other end. I would mark the white wire with a Sharpie stripe at both ends to identify it. We did it a lot and had no issues since all of my guys knew that the wire wrapped around the other pair was always the common. Personally I would never run travelers on a 2 wire cable even if there already was a neutral at both ends. It is too confusing to use black and white as travelers and if you don't know the circuits in the house, there is no guarantee that both neutrals are even on the same circuit. This could cause a neutral overload issue.
 

arkieguide

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Having served my union electrical apprenticeship in California - i remember the California 3 way well - not legal but works.
 
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