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3-way Dimmer Switch

DRJZ1974

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I am replacing an existing 3-way toggle switch with a 3-way dimmer switch. Problem I am having is that with the new switch, it only works if the switch across the room is switched one way, but not the other. The old toggle switch could be turned on or off from either side of the room. Any ideas? I have tried changing some of the connections and have double checked my connections, I can't get it to work. Thanks
 
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DRJZ1974

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I have a wiring diagram that came with the switch and I followed it exactly. Making sure to connect the common wire (which was hooked to the black screw on the old switch) to the common wire on the new switch. Nothing worked at all this way. When looking at the wires as they come into the conduit, there are two wires together and one wire wrapped around the two. The one that wraps around was the wire connected as the common with the old switch.

If I disconnect the switch and then test each wire with a circuit tester, which wires should test hot always? Test hot when the switch on the other side of the room is on? Which will not be hot at all without the switch in place?
 

hammlm

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The answers to your question depend on the position of the switch in the circuit and the position *of* the other switch in the circuit.

Is power feeding this switch, or the other?
 
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DRJZ1974

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I was starting to wonder if there was a difference in which order the power was feeding the switches. How do I figure this out? I don't know which one is being fed first?
 

hammlm

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OK;

Assumption: These are both three-way switches. (ie not one 3-way and one 4-way)

First, remove both switches. If you're not an expert, shut off the breaker first. On each, there will be one wire under a differently colored screw. Make sure you mark that wire. The other two are the travelers.

Don't un-wirenut or otherwise disconnect the neutrals.

Now, carefully, with the power on at the breaker, check each of the wires that you marked. One will be hot, one will be not. The hot one is the "first" switch in this series.

The marked wire in the other junction box will go to the light or device you are controlling.

Turn the breaker off.

Hook up the switches again, making sure that the travelers are on the two screws of the same color and the wire you marked is on the screw of a different color.

It's really that simple. Good Luck
 
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DRJZ1974

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Thank you for the help Hammlm, does this dimmer switch need to be on the first switch position? Also, I did check which wires were hot with the power on. I noticed the hot wires seemed to switch depending on which way I turned the switch across the room.

I did initially hook the common wire to the wire under the black nut and the other two as travelers and this did not seem to work. Given that this switch has been un-nuted, can I re-remove all wires from new switch and recheck which is hot as long as each wire is not touching anything? Thanks for your help, it seems like you are on the right track with me, just need to get this dialed in.
 

BetterDays

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Not to thread jack, but this was perfect timing since I will be experimenting with something like this shortly.

I presume that each switch is a dimmer or is one a dimmer and the other simply a switch?

If both are dimmer's, you would only be able to have power up based on the lowest setting of either switch, right?
 
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DRJZ1974

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In the original set-up, I could turn it on or off from either switch.
 

hammlm

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Hi;

You should only install one 3-way dimmer; the other should be a standard 3-way switch.

You'll be able to get back to the same configuration as before, don't sweat it.

You'll preset the 'dim level' on the dimmer and the other switch will just turn it on and off. You'll only be able to control the brightness from the dimmer (I guess that's obvious).

Yes you can remove all wires and re-check. I would highly recommed doing so. Turn off the breaker and unhook all the wires from both switches. Leave the neutrals and grounds connected to one another.

Make sure the wires are not touching anything and turn the breaker on. Out of the six wires you now have not connected to anything, one will be hot.

Turn the breaker back off. At the location with the identified hot wire, hook up either the dimmer or the switch. Put the wire identified as hot under the odd-colored screw (or wire, if there are leads on the dimmer). Hook the other two wires up to the remaining screw terminals or wires.

Without disturbing the other unconnected wires at the other location, turn the breaker on. One of the wires will be hot. Mark this wire. Go back to the first location and operate the switch (not the dimmer control, but the switch). Go back to the un-installed location. A different wire will be hot. Mark this wire. Turn off the breaker.

Now, take the device (either the dimmer or the switch) and install it by first connecting the UNMARKED wire to the odd-colored screw terminal or lead. Then install the two wires you marked to the other same-colored screw-terminals or leads.

Turn on the breaker and you should be good-to-go. If you are not, I would start to suspect this new dimmer. Replace it with the original three-way switch --- if everything works, replace the dimmer.


That should be it.


No, the dimmer does not need to be in the "first position". It can be either.
 
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DRJZ1974

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So one switch should have the "odd colored screw (I assume this is the "common") or black screw" hooked to hot and the other switch the common nut should be hooked to the only one not hot? Were getting close here! (I think anyway...) Thanks!
 

hammlm

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DRJ;

I re-read my instructions and then your question. I can't seem to reconcile them. Try the procedure, then let me know what problems you have. I'm happy to help.
 
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rburke65

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With a 3-way switch there will be one dark (black) screw, and 2 screws that are the same....silver in color maybe. If you were hooking up 2 3-way switches, ONE wire on one of the dark screws would be the HOT wire....(you only have ONE constant hot wire.) On the other 3-way switch, the wire on the dark screw would be the wire that goes to the light fixture. IF you havea 3-way DIMMER, then you will probably have one BLACK wire and 2 RED wires. The BLACK wire would be the equivalent of the dark screw and the 2 RED wires will be the equivalent of the 2 silver screws. You will have 2 wires the run between the 2 3-way switches, and they will attach to the 2 screws that are the same color or to the same colored wires in the case of the dimmer. These 2 wires are called "travelers" and can vary in color....they can be different colors! But they won't go to any other location....they just run between the 2 switch boxes. One dark screw will be the HOT wire and the other dark screw (or wire) will go to the light .....this wire is called the SWITCHED LEG. These can be very confusing for the rookie. Hope this helps. If it worked before then we can get it to work again.
 
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DRJZ1974

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Thanks guys! I am headed out of town until Sunday. I am hope I can open up the switch again Sunday and give your advises a try again there. I think I understand what you guys are saying and now makes sense to me, hope it works! Will let you know Sunday when I open it up again.
 
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DRJZ1974

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Ok, I took the dimmer out again, with all three wires separated (black, red, grey) I turned the power back on. Tested the wires, black: hot, red: not hot, grey: not hot. Fliped the switch across the room, Black: not hot, Red: hot, Grey: not hot.

None of the wires in this switch are constant hot, just switches between red and black depending on how the other switch is flipped. One wire is always not hot (grey wire) This is with no switch, just wire separated by themselves. Any ideas???
 
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DRJZ1974

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Dimmer switch has a Red, Blue, Black wires. (also has a green wire that is labeled ground wire for bare copper wire)
 
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DRJZ1974

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I think I have tried every wire combination, I can only get it to work one-way.
 
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DRJZ1974

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I tried a different dimmer, same results. So I don't think it is defective. What am I missing?
 

hammlm

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Ok, I took the dimmer out again, with all three wires separated (black, red, grey) I turned the power back on. Tested the wires, black: hot, red: not hot, grey: not hot. Fliped the switch across the room, Black: not hot, Red: hot, Grey: not hot.

None of the wires in this switch are constant hot, just switches between red and black depending on how the other switch is flipped. One wire is always not hot (grey wire) This is with no switch, just wire separated by themselves. Any ideas???

OK, you're on the right track. That grey wire is the wire to the fixture you are controlling with this circuit. You'll have to figure out on your dimmer which two are the travelers (I'd start with black and blue --- using the red for the connection to the grey wire).

Look at the instructions that came with the dimmer. Figure out which two wires are travelers and which two are switch legs.

You're almost there.


EDIT -- Post the manufacturer and part number of the dimmer.
 
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DRJZ1974

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Ok, I did
Black on Dimmer to Black in wall
Blue on Dimmer to Red in wall
Red on Dimmer to Grey in wall

This doesn't work at all, no matter how I switch the switch across the room. With power on, when I test the circuit, the black to black connection is hot and the blue to red connection is hot and the red to grey is dead. This tests this way either way I flip the switch across the room or turn the dimmer switch. Nothing changes and no lights will work.
 
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DRJZ1974

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I followed the directions and I swear I think I did it right, but it seems like when I follow the diagram is the only configuration that does not work at all. It seems like if I wire it in just about other combination, it works at least in one direction. Any thoughts?
 

mrb

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according to what you posted how you wired it, you did not do it according to instructions. You were wiring it how a normal 3 way would be wired, which will not work with this intermatic HA20 dimmer. Look at the wiring diagram again.

Find the other end of that grey wire and confirm that is the hot to the light fixture.

This dimmer must be at the power side of the 3way setup, you are trying to put it at the light side.

-Black on the dimmer goes to power.

-Blue on the dimmer goes to the light fixture (you use one of the travelers (the two unpowered wires between the two switches) for this -splice it to the wire that goes to the light fixture inside the box you currently have the dimmer in)

-Red on the dimmer goes to the second switch.

The second switch can be a regular switch or a 3 way switch. If its a 3 way switch, connect to the black screw, and one of the brass screws goes to the light.
 
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