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Discussion Starter · #1 ·
so i've decided to relocate and merge an electrical box. to make story short, i have a 3 way switch for the basement.

after some hands on research (existing wires), it seems that the previous owner had installed this configuration

http://buildmyowncabin.com/electrical/img12.gif




anyhow, i putz around.. and now switch 2 (the one away from the power source) can only be turned on and off while switch 1 (switch close to power source and light connection) is in the on position? WTF happened? i've tried numerous combos and now the wiring box looks like a total mess. please help..

one thing to note is that the previous owner placed the black and white cables in opposite positions as opposed to the diagram.
 

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Scared Electrician
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you have a traveler and the switch leg crossed.
 

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Master Electrician
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Cowboy is right. Set it up exactly like the diagram and you'll be good.
 

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The diagram will work, but technically shows a code violation of 200.7. The white can only be used as the feed to the switch.
 

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Your switches may have the terminals physically arranged differently. The common terminal is usually stained a darker color or has "C" engraved near it. If not you will need to look at the switch instructions, or use an ohmmeter (or continuity meter).

Or maybe you have a defective switch.
 

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Discussion Starter · #8 ·
you have a traveler and the switch leg crossed.
Cowboy is right. Set it up exactly like the diagram and you'll be good.

can you be a little more clear which one is the traveler and which is the switch leg on the diagram listed above? thanks

also what do you mean by "The white can only be used as the feed to the switch"??

tx
 

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If you look at the drawing you will see one of the screws on each switch is black. That screw is the common screw. It is important that the black wire be on that screw for this diagram to work. You need to look at your switches to identify the common terminal. It may not be physically in the same position.
 

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The diagram will work, but technically shows a code violation of 200.7. The white can only be used as the feed to the switch.
I don't think it is a violation. The fixture has black and white wires connected to it. That code is made so that you don't have two white wires at the fixture.
 

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At sw#1, the 2 black wires connected are the hot wires.
This feeds to sw#2, and connects to the common screw.

The white and red of sw#2 are the travelers, and connect to the other screws.

At sw#1 the black wire going to the light fixture is wires to the common screw to feed the light.
The red and white are considered the travallers and connect to the remaining screws.

The white wire from the breaker connects to the white wire going to the light.

Your colors may vary.

The common screw is a darker color, or marked with a C.

Older switches are harder to tell.
 

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Here is the section related to my post re white needing to feed switch.

(C) Circuits of 50 Volts or More.​
The use of insulation
that is white or gray or that has three continuous white
stripes for other than a grounded conductor for circuits of
50 volts or more shall be permitted only as in (1) through
(3).
(1) If part of a cable assembly and where the insulation is
permanently reidenti
fied to indicate its use as an ungrounded
conductor, by painting or other effective
means at its termination, and at each location where the
conductor is visible and accessible. Identi
fication shall
encircle the insulation and shall be a color other than
white, gray, or green.
[ROP 526]

(2) Where a cable assembly contains an insulated conductor
for single-pole, 3-way or 4-way switch loops and
the conductor with white or gray insulation or a marking
of three continuous white stripes is used for the
supply to the switch but not as a return conductor from
the switch to the switched outlet. In these applications,
the conductor with white or gray insulation or with
three continuous white stripes shall be permanently reidenti​
fied
to indicate its use by painting or other effective
means at its terminations and at each location

where the conductor is visible and accessible.

Note that this section will not be needed since the 2011 will require a neutral at the switch location.
 
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Master Electrician
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On one hand, I agree, I personally would use a re-marked white to feed power to the switch. On the other hand, would it not be allowed, as the re-marked white in the diagram is not being used as a return to the switched outlet? Or would you consider sw 1 (the one with the source feed) to also be an ‘outlet’ as per NEC definition? Curious on your thoughts.
 

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I too can see that point Kyle. I use the white as the feed and keep the blk/rd as travellers for consistancy. I don't think I have ever asked an inspector for their take on this.
 

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Problem is I don't consider that drawing a switch loop. The feed is at the switch not at the light fixture.
How would you like if the power feed went to the common of the first switch and the black from the far switch connected to the black to fixture.

 

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Functionally I don't see any difference between the two methods Joe.

Why would you not consider the wiring to the 2nd switch a switch loop? You are only taking hot conductors to and from the switch.
 

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Master Electrician
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You're right Jim, there is no difference in either scenerio. As long as the power goes to one common and the load to the other common, makes no difference which switch gets which or where it's located in the circuit. I know you guys know this, just saying.
 

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Kyles Rules for 3-ways are very helpful. You should make a sticky, Kyle ;)

  1. Power (feed; black from source) goes to one Common.
  2. Load (black, or reidentified white), from light goes to other Common (on 2nd switch).
  3. Source white (Neutral) goes directly to light.
  4. Travelers (red and black - if using 3-wire cable) connect to remaining terminals on switches.
  5. If a white is used as a HOT, it must be reidentified as such at both ends (black tape, or a Sharpie Pen).
 

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I am disputing the fact that it was said the white wire must be used to go TO the far switch as the power feed and the black used as a traveller. I believe that only applies to a feed at the light fixture so that you don't end up with two whites on the fixture.
 
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