[TimC527]

In my basement I have power (12-2) going to a 4 way gang box (A) at the top of my stairs. I would like to put four separate 3-way switches in that box to control 4 separate sets of lights. In the basement is a second 4 way gang box (B) that will have 4 3-way dimmers to control the same 4 sets of lights that will be controlled at the top of the stairs. So far, I ran three separate sets of lights (each with 12-2 wires) to gang box B. I have also run one 12-2 wire for one set of lights to gang box A. I have run two separate runs of 12-3 wire between gang box A and gang box B. I plan to run another two lines of 12-3 between gang box A and gang box B. In gang box A, I hooked the incoming 12-2 (wire is from the panel) to the first 3-way switch and 12-3 wire is attached to that same 3-way switch. White wires are wire nutted together. Black from 12-2 is on the black screw of the 3-way switch. Red and black wire from 12-3 line are on two different screws of that 3-way switch. The switch in gang box B is wired the same way with 12-2 outgoing to a set of lights. Those two switches work like they should.
QUESTION: How do I wire the second set of 3 way switches? Please explain which wires go on which screws at both boxes. I assume the third set of switches will be the same.
Will the fourth set of 3-way switches be the same even though the lights will be powered from a 12-2 line coming off of box A? I also assume that I have to run a separate 12-3 line between box A and box B for each set of switches (in this case there will be 4).

 

[joecaption]

Just being nosy why in the world would you want all the light controls at the top of the stairs?
Why not just a 3 way for stair lighting at the top and bottom and the rest down stairs.

 

[AllanJ]

Do not wire together all the whites in the lower box (box B).

For the light wired to box A do this:

It too must have a 3 wire cable going down to box B.

Connect the 3 wire cable white to the cluster of blacks (raw hot) at the top (Box A). Connect the light cable black to the top switch common terminal.

At the lower box connect the white to the common terminal and the red and black to the traveler terminals.

For the other three lights connect the whites of their 3 wire cables all to the neutral white (power cable) at box A. Connect red and black to traveler terminals. In the lower box (Box B_ cpmme cpm cop connect the individual white of the 3 wire cable to the individual white of the light cable. COnnect the black of the light cable to the switch common.

 

[TimC527]

Thanks for your explanation Allan J. Just a few follow-up questions:

When you said, "Connect the 3 wire cable white to the cluster of blacks (raw hot) at the top (Box A)." In Box A - Do I connect all four 3 way white wires and the white wire from the one 12/2 (power in) into one cluster?

Where does the one white wire (12/2) that goes from the light into Box A attach?

Joecaption - good question. I currently have full access to walls and ceilings...and I know that my kids will leave lights on all the time and I'll get tired of having to walk "all the way" down the steps to turn off lights.

 

[Baxter01]

Joecaption - good question. I currently have full access to walls and ceilings...and I know that my kids will leave lights on all the time and I'll get tired of having to walk "all the way" down the steps to turn off lights.

I guess I don't see how wiring four 3-ways at the top of the stairs is a solution to children with little respect for their parent's requests or wishes. I know we got switches when we left the lights on but they weren't the 3-way type.

 

[stickboy1375]

.and I know that my kids will leave lights on all the time and I'll get tired of having to walk "all the way" down the steps to turn off lights.

Here's what I do, "Kids, go shut the lights off!"

 

[joed]

Pigtail the power feed with four wires. Connect all the whites together except the one for the light fed at the top switch. That white will be used as a traveller.

Wire the first switch with lights at top of stairs like this drawing using one of the power feeds.

Take the other three power feeds and wire this setup three times for other three switches.

 

[hammerlane]

Had this diagram saved showing two sets of 3-way switches. Shows with power coming into the left set and switched power leaving the right set.

No grounds shown for ease of drawing.

 

[SquishyBall]

Just being nosy why in the world would you want all the light controls at the top of the stairs? Why not just a 3 way for stair lighting at the top and bottom and the rest down stairs.

Too funny!

Only cuz we're doing a similar thing in our basement. 3 switches tho, not 4. Same basic setup... power from the panel to the basement switch. Then 3 sets of travellers (and a neutral) to the switch at the top of the stairs. Then switched power from there to the fixtures.

Rather than run from there right to the fixtures tho, I'm actually sending the switched power back down to a box in the basement ceiling. From there, I can distribute to the lights. This way only one conduit has to run from the switch back down, which is cleaner, simplifies that box at the top of the stairs and keeps the box-fill under the limit.

I'm only doing a 2-gang box, using one full size touch / 3-way dimmer for the main lights and then one double 3-way switch for the rest of the lights.

We have this setup cuz our basement has two areas... at the bottom of the stairs will be a desk / computer area. It's about 9x9. This area will have 2 or 3 recessed cans. Then the main area is about 12x12, and has a couch, coffeetable, and entertainment / game center. This area is on the dimmer, since setting the lights to custom levels could be useful here. The 3rd switch is going to power some accent lighting in the entertainment center. This one doesn't really have to be a 3-way, but I figured the other two are, so why not. It's not like a 3-way/2-way switch is much cheaper than a 3-way/3-way switch.

 

[Billy_Bob]

FYI - A regular switch 4 gang box has a LOT of wires to "cram" in there. All 3-way switches and even more wires!

A way to get more space in the box (elbow room), is to go to an electrical supply (where electrician's shop) and buy/order a 4 gang plaster ring and the deepest box for that they have. Or a box with an extension to make it deeper. With this there will be extra space on both sides. Also when installing this, be sure to use a level across the top. Any sort of slant with a 3/4 gang box is quite noticeable. Here is what that plaster ring looks like...

 

[AllanJ]

Thanks for your explanation Allan J. Just a few follow-up questions:

When you said, "Connect the 3 wire cable white to the cluster of blacks (raw hot) at the top (Box A)." In Box A - Do I connect all four 3 way white wires and the white wire from the one 12/2 (power in) into one cluster?

Where does the one white wire (12/2) that goes from the light into Box A attach? .

For the neutral connections, the whites for the three 3 wire cables that will serve the lights wired to Box B, and the white of the (2 wire) power feed, and the 2 wire cable white for the light wired into Box A are all in one cluster.

The remaining white (of the 3 wire cable for the switches for the light wired into Box A) is put into the cluster of blacks. Put a stripe using black tape or stain on both ends of this white wire.

 

[TimC527]

Thanks a lot for the detailed explanations and the diagrams, all of which helped me. I even put a third switch (4-way) in the middle of the fourth string of lights.

 

[stickboy1375]

You should always to try to make it ascetically pleasing and easy to flow through the house, not install 3 to 4 gang switch boxes on every wall, its just going to add confusion and be a real pain in the ass, and expensive with all the wasted material, a well laid out switching plan is much better than a I think I want this because i dont know what i want scenario.