Replies

1. 
   pm22 | Dec 13, 2009 06:50pm | #1

   You only need a three conductor cable between light 1 and light 2.

   You need it also between the first switch and light 1 and between light 2 and the second three way switch. You can use 14- or 12-2 between the source and switch number one. Look up a chart or diagram on the web for what you're doing.

   ~Peter

1. 
   RichMcD | Dec 13, 2009 07:38pm | #2

   Peter,

   Thanks - i guess am missing something. The closest diagram I have found calls for 2 2-wires connectors between the lights. With a single 3 wire connector do I need to use the ground to carry a load?

   
1. 
   pm22 | Dec 13, 2009 10:47pm | #3

   The ground wire is connected to each box and is assumed.

   The white, neutral, grounded conductor goes directly to the two lights at the silver screws.

   The source wire goes to the first three way and attaches to the common. Then the two travelers go to the two traveler contacts on the other three way. The common from the second three way goes to the two lights to the gold terminals.

   So you would have to identify all of the wires in this system.

   My first post was, regretably, incorrect. You have a white and a black to the first switch box. Then you use 14-3 to send your white to light #1 and two travellers. Then you have 14-4 to light #2. White as stated. Red and black are the travellers. Blue goes from the gold terminalon light #1 to the gold terminal of luminaire #2. Red and black are tied respectively together.

   At light #2, black to black [traveler]; red to red [traveller], white to blue [re-identify with tape]. At switch #2, white is second common [re-identify with tape], red and black to common of switch.

   ~Peter

1. 
   RichMcD | Dec 14, 2009 12:03am | #4

   Peter, as in noted in my original posting this was a fully functioning circuit with a single 12-3 or 14-3 between the two lights. Had I simply bothered to pay attention to how the light was wired I wouldn't have this problem. Here is what I am confident in; Switch1 has the hot on the common and the neutral bonded to the neutral in the 14-3 that leads to Light1 ; the black and red conductors from the 14-3 leading to light 1 are attached to switch1 (the red conductors appears to be bonded in each junction box and terminates at switch2) and the ground is bonded to the ground in the 14-3 that leads to Light1. Switch2 has a 14-3 coming in from Light2; the neutral is being used as a carrier (white that has been marked with black tape) and terminates switch2's common terminal. The ground from the 14-3 appears to be bonded to something outside this box which leads me to believe that the person who wired this used the ground in the 14-3 between light1 and light2 to carry a load. I will draw out the elements of the circuit that I have not disturbed however I will not be in a position to do that until Tues evening. Again, thanks for helping me work through this.

1. 
   DanH | Dec 14, 2009 07:21am | #6

   If there's a "real" 4-wire
   If there's a "real" 4-wire (not counting ground) wire running between the two lights, there'd be no reason to use the ground wire as something else. (No justification in doing it in any case, but that's a different story.) You do need 4 insulated wires between the two lights.

2. 
   DanH | Dec 14, 2009 07:18am | #5

   Pretty sure you need 4 wires between light 1 and light 2: Switched, neutral, and two travelers.

   Coming from switch 1 you oddly only need 3: Neutral and two travelers. The "switched" wire feeds back from switch 2 to the two lights, so 3 wires again to between light 2 and switch 2.

1. 
   DanH | Dec 14, 2009 07:23am | #7

   (No subject)
   View Image

1. 
   DanH | Dec 14, 2009 07:24am | #8

   Note in the above two x2 cables are used in place of the single x4. I've heard conflicting stories on whether the double x2 is legal.

1. 
   jimjimjim | Dec 14, 2009 03:01pm | #9

   Dan,

   My take on 1 X 14/4 vs. 2 x 14/2 between the lights is that 2 x 14/2 is appropriate as long as the (black) switched hot and (white) true neutral between the lights are in 1 14/2 cable. If you cross the wires in the 2 cables on both ends, the circuit will work but will not be code correct. But I'm sure others may require a single 14/4. I wouldn't do this with 2 parallel EMT conduit runs (and there would be no reason for it). 2008 NEC 300.5(I)

   Regards,

   Jim x 3

2. 
   RichMcD | Dec 14, 2009 07:23pm | #10

   Thanks to all - now I need to figure out the easiest way to pull a new wire between the two boxes. The run is only about 10 feet but the the ceiling is a textured plaster and there is no access from above. I guess I can hope that the single 14/3 is not tacked down and try pulling it through with a line attached.

3. 
   DanH | Dec 14, 2009 08:34pm | #12

   Good luck with that! Keep in mind that another option is to buy "smart" switches.

4. 
   DanH | Dec 14, 2009 08:33pm | #11

   The issue I've heard is that
   The issue I've heard is that the current flow through any cable (or conduit) is supposed to net to zero. No way I can see that happening without a 4-wire cable.