Can Lights on three-way switch question
#1
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Can Lights on three-way switch question
Here's what I am trying to do in my basement: Power source to First can light, to second light, 3rd, etc. Then to a three-way switch; and then to the other switch. I want to use this setup in order to utilize the existing circuit without using junction boxes.
I thought I kind of understood what to do: 14/2 wire to first light; then 14/3 between lights; then 14/2 to first switch; 14/3 to second switch. If this is right, how do the connections look between lights? The can lights have quick connects for ground, white, and black. Should the red wires just be quick connected with the black wires?
I thought I kind of understood what to do: 14/2 wire to first light; then 14/3 between lights; then 14/2 to first switch; 14/3 to second switch. If this is right, how do the connections look between lights? The can lights have quick connects for ground, white, and black. Should the red wires just be quick connected with the black wires?
#2
Welcome to the forums.
You are creating a switch loop at the end of the circuit. Technically this is not to code as you are required to have a neutral at least at one switch location. You could use a three wire cable from the last light to the first switch. That would bring neutral to the first switch where it would be just capped off unless needed.

The lights would connect to the red and white wires. The blacks are carried thru.
You are creating a switch loop at the end of the circuit. Technically this is not to code as you are required to have a neutral at least at one switch location. You could use a three wire cable from the last light to the first switch. That would bring neutral to the first switch where it would be just capped off unless needed.

The lights would connect to the red and white wires. The blacks are carried thru.
#3
Simplest is to bring power to the switch first but what you want to do is doable.
At the first light:
At the last light run a 3-conductor cable to the first 3-way switch.
This gives you the code required neutral at the switch. The black for constant power to the 3-way switches and red to carry switched power back to the lights. To meet code you will probably need a 4-conductor cable (red, black, blue, white) between the switches.
Here is how the switches are wired:

Location of common terminal may be different on your switches.
Darn, Pete types faster.
At the first light:
- Black of power in 2-conductor cable to black of power out 3-conductor cable
- White of power in 2-conductor cable to white of power out 3-conductor cable and white of the light.
- Red of three conductor cable to black of light.
- At each of the other lights red to light black.
- Black in to black out.
- White in to light white and white out.
At the last light run a 3-conductor cable to the first 3-way switch.
- Red in to red out and black of the light.
- Black in to black out to switch.
- White to white out and light white.
This gives you the code required neutral at the switch. The black for constant power to the 3-way switches and red to carry switched power back to the lights. To meet code you will probably need a 4-conductor cable (red, black, blue, white) between the switches.
Here is how the switches are wired:

Location of common terminal may be different on your switches.
Darn, Pete types faster.
Last edited by ray2047; 03-22-17 at 04:15 AM.
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Thanks and a follow-up
Sorry for not responding sooner. I had some trouble logging in and just gave up after a while. I really appreciate your responses. I was not aware of the neutral wire in the switch box requirement. Having considered everything I am trying a new approach:
I just have enough existing wire to reach one switch location, so I will run source --> First Switch --> Second Switch --> to the lights (14/2, then 14/3, then 14/2).
However, I also want to run two additional set of three-ways off this circuit, along with an outlet. Is this doable? The attached image reflects what I am thinking; not sure about how to get power to the other switches and outlet.
I just have enough existing wire to reach one switch location, so I will run source --> First Switch --> Second Switch --> to the lights (14/2, then 14/3, then 14/2).
However, I also want to run two additional set of three-ways off this circuit, along with an outlet. Is this doable? The attached image reflects what I am thinking; not sure about how to get power to the other switches and outlet.

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Let's try this again.
Switches 2 3 and 4 intended to be in the same box. I think I know what to do with 4. Just need some help with the wiring on 2 and 3.
Switches 2 3 and 4 intended to be in the same box. I think I know what to do with 4. Just need some help with the wiring on 2 and 3.

Last edited by ukdjm; 03-29-17 at 07:04 PM.
#9
You are correct. Since power comes in at switch 1..... there is no always hot at the 2,3,4 location.
You also show many cables above switch 2 coming to that box. Those may be just devices powered off the same circuit but plan your wiring to keep cable count as low as possible.
You also show many cables above switch 2 coming to that box. Those may be just devices powered off the same circuit but plan your wiring to keep cable count as low as possible.
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Update. Here's what I am thinking; need some help with the connections between 1 and 2 and the other 4 wires on the left. C marks the common terminal and orange is used for white wires.
Good point on the number of wires. I need to calculate the capacity. If needed I can move something around.
The wiring from switch 1 to the stairway light and to the other switch for that light are behind drywall as the stairway was finished by the builder. Same goes for the wiring to the outlet.
Good point on the number of wires. I need to calculate the capacity. If needed I can move something around.
The wiring from switch 1 to the stairway light and to the other switch for that light are behind drywall as the stairway was finished by the builder. Same goes for the wiring to the outlet.

Last edited by ukdjm; 03-31-17 at 10:39 PM.