ganged wall switches with a dimmer


Old 03-24-07, 12:09 AM
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ganged wall switches with a dimmer

Here is the scenario: 1 3way switch at the bottom of the stairs (light is at the top of the stairs), at the top of the stairs there is a ganged (2 switches together) 1 of the ganged switches works the same light as the switch at the bottom of the stairs and the other works a second light also located at the top of the stairs and this one is also a 3way switch. What I am trying to do is install 2 dimmer switches. This is where I get confused...where the ganged switches are there are 3, 3wire cables entering the box, the dimmer switch has 2 red wires and 1 black and the switch next to it is a regular 3way switch. My question is which wires do I nut together and which wires go to the switches? The second dimmer is going to be located at a third switch. I did have them connected but the dimmer switch in the ganged box would only work if the switch at the bottom of the stairs was turned on so what am I doing wrong? It's those red wires that mess me up!
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Old 03-24-07, 05:33 AM
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Hopefully you either took a picture or notes for how the switches were wired before you took any connections apart.

The problem most likely is that you have a wire crossed on the three way switch. On a standard switch you have two screws that are brass in color and one that is black. The black screw is the point or common terminal and the two brass screws are the travellers. On your new dimmer, the red wires are travellers and black wire is the point.

There should be no need to mess with any of the wire nuts that were tucked up in the back of the box. You will be taking three wires off of screws and putting each of the three to one of the wires on the new dimmer switch.
Old 03-24-07, 06:12 AM
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As jwhite stated, the same wires get connected to the replacement switches that were connected to the original switches, and to the same terminals.

One comment, however. I would not dim a stairway or a hallway light, especially when three way switches are involved. These lights are present to provide light for walking, so you can see the stairs and so you can step over the toys that the kids (or spouse) left in the way.

I would not want to approach the stairs from the normal (non-dimmable) switch end to find the dimmer all the way down (some are effectively off when they are all the way down or low).

Please consider safety before aesthetics.
Old 03-25-07, 03:47 AM
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The Stairs Are Lit Seperately, But Thanks For Your Concern. Had The Original Switches Been Installed Properly I Would Of Done The Obviuos And Connected The New Dimmers The Same Way....directions I Can Read, However, The Explanation Of The Travelers And Common Wires Switching From Red To Black And Black To Red Did Help.
Old 03-25-07, 08:17 AM
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Turn off the caps it makes it hard to read.
Are you saying the original switches did no work properly before you started this project? If that is the case then you need to tell us all the wires in the switch boxes and the fixture. Make special note of which wire is connected to the common screw. The common is the black screw or marked common.

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