3 way mistake...


Old 10-29-05, 11:32 AM
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3 way mistake...

Just finished rewiring my kitchen, and everything on all 5 circuits works fine with one exception, my 3 ways that control my 3 pendants in the ceiling. One 3 way will light the pendants, the other will throw the breaker. They are wired correctly at the switches. I changed the switch that trips, no difference. I brought the source up to the first ceiling box (This is a lighting circuit) and wired the source hot directly to the first run of 12/3, white to the other run of 12/3 and red as well. The lights took the neutral, and I pigtailed the hot lines together going to the lights and the other run of 12/3. Everything in this circuit works, cannisters over the sink, pendants, entry lamps, chandalier. But just flip that 1st 3 way and the breaker trips. I'm sure I have made a simple mistake somewhere, but the 300 feet of line and numerous devices installed may have made me stupid, so please advise me of the obvious, what ever it may be! The first box also has the line to my cannister lights spliced in with the source.
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Old 10-29-05, 01:16 PM
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OK, let me see if I have this correct:

You have two three way switches (call them SW1 and SW2).

You have a light fixture mounted to a box that has a 12-2wg coming in (call this NM1), a 12-3wg going to SW1 (NM2), and a 12-3wg going to SW2 (NM3). I'm assuming you also have an additional 12-2wg going to the next light fixture (NM4).

Is all this correct?

If so, here's how I'd wire it:

Fixture box:
NM1 black to NM2 black.
NM1 white to NM4 white and to fixture white.
NM2 and NM3 reds together.
NM2 and NM3 whites together.
NM3 black to NM4 black and to fixture black.

SW1 and SW2 should then both be wired with the black wire to COMMON, red to one traveler screw and white to other traveler screw.

All grounds should be tied together and connected to fixtures and/or screws, as applicable.

Reidentify both ends of NM2 and NM3 white wires with magic marker or electrical tape to identify them as hot wires.
Old 10-29-05, 01:29 PM
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3 way mistake

Yes, that's what I have. I suppose I will have to open the first ceiling box to make certain, but what you described is the way I wired it. What am I looking for?
And why would one of the 3 ways work but not the other?
Old 10-29-05, 01:48 PM
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I suspect you may have mixed one of the white traveler wires with one of the white neutral wires. When the combination of switch positions are just right, you are connecting the neutral directly to the hot feed, thus creating a short and tripping the breaker.

The ceiling box is almost certainly where the problem lies.

Only other possibility I can thing of is that you have a ground wire in contact with one of the other wires somewhere (touching a screw, touching a wire with damaged insulation, etc.).
Old 10-29-05, 03:15 PM
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Makes sense, I will check it. Curious. Of the three pendant lights, only the one in the main ceiling box where all the activity is will light. That tells me that their n (the other two pendants) neutrals must be crossed with the switch that throws the breaker.

Does this sound logical?

Thank you for your help today!
Old 10-29-05, 07:26 PM
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In your case, the easiest thing to do is to correctly wire the two switches and one light. When that works properly, connect the line that goes to the second and third lights to the same wires that go to the first light.
Old 10-30-05, 08:59 AM
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This link shows some two light three way and four way configurations.


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