3 way dimmer switch

[hbiss]

Original post:

*at the location of the dimmer*, I have the power coming in, the switch leg up
To the light, and a 12/3 wire running to the toggle switch...

Now you say:

I explained my scenario as clearly as possible.. I’m not sure how it is confusing to understand... at the dimmer switch there is as follows: FEED-IN, SWITCH LEG, and 12/3 to 3-way toggle switch..... I can operate the lights from the dimmer, and I can shut off the lights from the toggle. When that happens, I can no longer switch the lights ON from the dimmer switch.

Clearly as possible?? Now you change your story too! Now the light fixture is missing!

What have you got?? I understand feed in>dimmer>light fixture>3-way switch. What cable do you have running from the dimmer to the light?? IS IT A 12/3?? because you make it sound like is is only a 2 wire!!

-Hal

 

[LarryFine]

What have you got?? I understand feed in>dimmer>light fixture>3-way switch. What cable do you have running from the dimmer to the light?? IS IT A 12/3?? because you make it sound like is is only a 2 wire!!

As I read it, the 2-wire feed in, the 2-wire to light, and the 3-wire to the second switch box all meet up in the first switch box.

The way he had it, the second switch behaved as a master-off switch; that the light only works with the switch in one position.

 

[kwired]

Original post:


Now you say:

Clearly as possible?? Now you change your story too! Now the light fixture is missing!

What have you got?? I understand feed in>dimmer>light fixture>3-way switch. What cable do you have running from the dimmer to the light?? IS IT A 12/3?? because you make it sound like is is only a 2 wire!!

Geeze! Like pulling teeth. Are you sure you are an electrician?

-Hal

What he has not cleared up and you assumed (don't worry I kind of did as well) that what he is calling "switch leg" is 12-2 and not 12-3. Standard three way switch or dimmer switch will have exactly the problem he mentioned if he only only has 12-2 in that segment of the circuit. That segment needs the neutral and two "traveler" conductors.

"Switch leg" to me means take power from the light location and bring one conductor to a switch, and one conductor back from the switch. If doing so with a cable wiring method it is a two wire cable. Now with more recent codes requiring a grounded conductor at the switch in many cases, it could still be a "switch leg" as I described plus one more conductor for the required grounded conductor.

 

[Little Bill]

He's calling the cable from the light the switch leg. What he has is the following (unless I'm reading it wrong)
First box: Power Hot/neutral, cable from light (I assume 12-2) and a 12-3 going to the other box
2nd box: Just the 12-3 from the 1st box
So has has a "dead end" 3-way.
Larry already described this but this is how it should be wired.
First box:
Incoming neutral to the neutral from the light
Incoming hot/black to the white wire of the 12-3
Red & black from 12-3 to the traveler terminals
Black from light to the common on the 3-way

2nd box:
White from the 12-3 to the common terminal
Red & black on the traveler terminals.

Side note:
I'm calling the dimmer a 3-way even though it is a dimmer, wires the same
Probably need to re-identify the white from the 12-3 to black (marker or tape)

 

[Little Bill]

What he has not cleared up and you assumed (don't worry I kind of did as well) that what he is calling "switch leg" is 12-2 and not 12-3. Standard three way switch or dimmer switch will have exactly the problem he mentioned if he only only has 12-2 in that segment of the circuit. That segment needs the neutral and two "traveler" conductors.

"Switch leg" to me means take power from the light location and bring one conductor to a switch, and one conductor back from the switch. If doing so with a cable wiring method it is a two wire cable. Now with more recent codes requiring a grounded conductor at the switch in many cases, it could still be a "switch leg" as I described plus one more conductor for the required grounded conductor.

That would be a "switch loop". A leg is just one switched hot, and neutral from the switch up to the light.

 

[hbiss]

I read it to be a two wire from the dimmer (switch leg) to the fixture and a 12/3 from the fixture to the 3-way location. I interpreted that way because why else would there be a problem.

Ok, I'll read it again.
*at the location of the dimmer*, I have the power coming in, the switch leg up
To the light, and a 12/3 wire running to the toggle switch...

If you have at the dimmer location the feed, a 12/2 to the fixture and a 12/3 to the 3-way you need a 3-way dimmer and to wire it properly.

-Hal

 

[sameguy]

Did I pass?

JUST!

 

[kwired]

I read it to be a two wire from the dimmer (switch leg) to the fixture and a 12/3 from the fixture to the 3-way location. I interpreted that way because why else would there be a problem.

Ok, I'll read it again.
*at the location of the dimmer*, I have the power coming in, the switch leg up
To the light, and a 12/3 wire running to the toggle switch...

If you have at the dimmer location the feed, a 12/2 to the fixture and a 12/3 to the 3-way you need a 3-way dimmer and to wire it properly.

-Hal

OK after "reading it again" it could be that all those cables mentioned come to the one switch box, which will work if connected correctly.

 

[hbiss]

OK after "reading it again" it could be that all those cables mentioned come to the one switch box, which will work if connected correctly.

To a 3-way dimmer.

-Hal

 

[ActionDave]

To a 3-way dimmer.

-Hal

Which i believe is what the OP has based on nothing but the thread title to start.

 

[hbiss]

Which i believe is what the OP has based on nothing but the thread title to start.

Depends on how you read that too!

-Hal

 

[kwired]

To a 3-way dimmer.

-Hal

To any SPDT switch AKA "three way".

 

[ActionDave]

Depends on how you read that too!

-Hal

Well then there's this in the body of the text of the OP

I have a set of 3 way switches, one being the dimmer, and the other being a standard 3 way

 

[Little Bill]

I don't understand why you guys are having such a hard time reading what the OP wrote. I just had to clarify that he had line/load in the same box, the rest was pretty clear with maybe the exception of calling the load wire a "switch leg".

 

[ActionDave]

I don't understand why you guys are having such a hard time reading what the OP wrote. I just had to clarify that he had line/load in the same box, the rest was pretty clear with maybe the exception of calling the load wire a "switch leg".

I agree

 

[hbiss]

Well then there's this in the body of the text of the OP

I have a set of 3 way switches, one being the dimmer, and the other being a standard 3 way

Fair enough, guess I'm not accustomed to describing it that way. Point is, this guy says he is an electrician so I'm looking for some reason that an electrician would be having this problem and I guess it got lost trying to find something in what he was saying. Any electrician should know how a 3-way works and the various configurations but he had doubts about whether the wiring was run correctly. It turns out that it apparently is. If he had doubts about the wiring and how to wire the devices, the only thing that I can think of is that he isn't using a 3-way dimmer.

So if he is, then at this point it is really a DIY level problem and all I can advise is read the instruction sheet that came with the dimmer.

-Hal

 

[kwired]

Fair enough, guess I'm not accustomed to describing it that way. Point is, this guy says he is an electrician so I'm looking for some reason that an electrician would be having this problem and I guess it got lost trying to find something in what he was saying. Any electrician should know how a 3-way works and the various configurations but he had doubts about whether the wiring was run correctly. It turns out that it apparently is. If he had doubts about the wiring and how to wire the devices, the only thing that I can think of is that he isn't using a 3-way dimmer.

So if he is, then at this point it is really a DIY level problem and all I can advise is read the instruction sheet that came with the dimmer.

-Hal

Or something is connected wrong or maybe malfunctioning.

Some three way dimmers like to trick you if you don't look at instructions. Common terminal isn't what you think it is just looking at it.

 

[readydave8]

I often find 3/ways quicker to trouble shoot if I take one of the switches out and wire nut common to one traveller and then to the other

We've occasionally found new 3/ways that were bad

 

[Fred B]

I often find 3/ways quicker to trouble shoot if I take one of the switches out and wire nut common to one traveller and then to the other

We've occasionally found new 3/ways that were bad

For a while I've found an almost 50% failure rate of 3way dimmers, new from package, especially when they first started to make them usable on LED, they've improved recently though I still get an occasional bad one.