3-way switch problems

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  #1  
Old 09-01-13, 10:07 PM
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3-way switch problems

Owner/builder here...All new construction. I have been sure up to this point that I did everything 100% right, much thanks to forums like this.
Right now I am having a very strange problem with a simple three way switch that will control a single hallway light with a toggle switch.

I've looked at so many diagrams and read so many different posts...I think my set-up is correct but something isn't working right so maybe not.

On a two occasions, it has worked correctly and then stopped exhibiting the same symptoms afterwards.

I am sure I have it wired correctly as follows:

12/2 coming from the breaker to a switch/box.

This box controls a dimmer switch that has worked fine for several months.

In this box, I also have:

1. A line to another switch that controls some lights. They also have worked fine for some time.

2. A line to the lights controlled by this dimmer switch. These lights work fine also.

3. A line to the first switch/box of a 3-way light system controlling a single hall light. The black from this line feeds the common on the first switch.
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The line into the first switch/box on the 3-way circuit has 12/2 coming in Name:  DSCN6141.jpg
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It has 12/3 running to the second switch/box on the 3-way light. The red and black wires from the 12/3 are on the transfer screws on the first switch..

In the second box on the 3-way light, I have 12/3 coming in from the first switch. The black and red are both connected to the travelers like the first switch. 12/2 going up to the light and the black wire is connected to the common screw on the second switch.

I have tried 6 switches now.

The symptom is that when I connect the first black common on the first switch for the 3-way light, both transfer screws become hot. If I connect the transfer wires, both are hot on the other side as well, regardless of the first switch position. If I connect the black wire that travels to the lamp to the common on the second switch, the lamp wire tests hot also.

If I remove one (1) transfer wire from the first switch, the first switch will control the lamp/black wire.

If the first switch is one way, the lamp wire tests hot, If I flip the switch on the first switch, the lamp wire tests off. There is no light on it, just the 3 wires. I have not tried it with a lamp.

I have rewired from the first picture to clean up the copper wires. I thought that maybe I was getting a short from that.

I bought 2 new switches, again, and hooked them up outside the box.

Same symptom immediately.

I have been using all the other lights for a long time. I didn't have a hall light so I don't know how long I've had this problem.

I am testing with an electrical tester that lights up and beeps. It is a good tester but doesn't measure ohms.

Don't know what else to check. Thanks for reading
 
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  #2  
Old 09-01-13, 10:24 PM
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I am testing with an electrical tester that lights up and beeps.
That type of tester is not used for what you're doing. A non contact tester has only ONE purpose.....to let you know there is dangerous voltage in the area.

You need a voltage tester with leads or a voltmeter.

It sounds like you are wiring it right. Although it looks and sounds like you have a lot of wire in your boxes....especially it being #12.

At your first 3 way switch.... you are supplying the common with hot. Then you are using the red and black in the 12-3 as your travelers. That would mean that the white is just carried thru as neutral. At your second switch.... the red and black are travelers and the black of the two wire going to your light goes to the common on the switch, The neutral is just carried thru.

Stick a light on the ceiling and see if it works....never mind the tester.
 
  #3  
Old 09-02-13, 07:13 AM
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I have a voltmeter with leads... I will try with that although the wire for the lamp is far from any other hot wire. With everything connected, It is always hot so I'm pretty sure I have a problem.

I did cut down some of the wire too.

I wondered about a short, but I don't know where it could be. I guess that's where the voltmeter comes in. I was very careful but things happen.

Thanks for the advice
 
  #4  
Old 09-02-13, 07:28 AM
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In the first picture, I don't see a 12-3 in the box. But I'm old and bifocals only work on Wednesdays How are you connecting the two switches, and why did you use 12- cables? What a pain.
 
  #5  
Old 09-02-13, 08:10 AM
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In the first picture, I don't see a 12-3 in the box.

Read more: http://www.doityourself.com/forum/ne...#ixzz2dkDKhV00
Me either I'm thinking 12/2 was used for the travelers:NO NO NO:
 
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Old 09-02-13, 08:47 AM
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In the first picture, I don't see a 12-3 in the box. But I'm old and bifocals only work on Wednesdays How are you connecting the two switches, and why did you use 12- cables? What a pain.
In addition, there is too much sheathing on the NM cables in the box and there is no wire nut on the ground wires (no pigtail to ground the switch either). These things shouldn't keep the 3-way switches from working, but they are indicative of the overall electrical system in terms of code compliance and workmanship.

Me either I'm thinking 12/2 was used for the travelers


But, in defense of the OP, I don't believe the first picture is the first of the two 3-way switch boxes. I am not sure why this first picture is pertinent. He does, however, say there is a 3-wire cable (12-3) connecting the two 3-way switches. That being said, the second picture of the first 3-way switch box shows the same compliance and workmanship issues as the first picture.
 
  #7  
Old 09-02-13, 08:50 AM
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Your pic with the dimmer needs to have travelers and all I see is 12/2. The 3 way dimmer has a lead capped where both leads are travelers. This is what happens when builders do their own electrical work?
 
  #8  
Old 09-02-13, 11:20 AM
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testing

Man... I'm definitely looking for advice and direction but can you add some sugar please? lol...but Bring it on... I'll get it one way or another!

I'll try to address some of the questions in the different posts. Obviously there is some confusion.

I did take the pictures with the wire pulled out after I had been working on it for a while so it does look like its a mess, but I did try to carefully put it in the wall the first time, with caps on everything. It will be neat and clean when I'm done.

I used 12 wire because I used a 20 amp breaker.

The 12/3 is not in the first box at all. I showed the first box to show the line in from the breaker, and where everything originated from.

The dimmer is not part of the 3-way light, It controls a set of can lights that have worked perfectly for some time. There is a feed to the first box on the 3-way light. This feed is 12/2.

In that box, (second picture shows the first box for the 3-way light), The 12/2 is coming in from the bottom. That is the common on my switch. I have 12/3 going out of the top and over to another switch. (switch 2 of the 3-way light)

The black and red wires of the 12/3 are the transfer wires on the second switch, and 12/2 is going up to where the light will be.

I'll look thru the posts again and see if I missed anything.

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I have been using the pointer that just tests for power.

I would like to test for continuity to see if there is a short somewhere. Maybe a staple or nail?? I don't know how to do it exactly, but I believe the meter will let me.
 
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  #9  
Old 09-02-13, 11:24 AM
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My setup exactly

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This is my setup exactly.

12/2 from the feed switch
12/3 between the two 3-way switches
12/2 to the light fixture
 
  #10  
Old 09-02-13, 11:25 AM
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Maybe if we back up and you post pictures of the pertinent switch boxes with the wires separated and capped, we can come up with better solutions. If the first pix has nothing to do with the switching we didn't need it. I think it is more important for us to see the switch box wiring on both ends, and possibly the wiring from the ceiling canopy.
 
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Old 09-02-13, 11:28 AM
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Master teacher

Thanks for reading it carefully and giving such good advice. You're awesome! I don't know what I was thinking... Trying to do something on my own and learning new things. What an idiot I was being. Thanks again for setting me straight Danny7633
 
  #12  
Old 09-02-13, 11:43 AM
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You sound a little hurt. I'm sorry if I hurt your feelings however your post is very confusing and makes it hard for people to help you. If you wanted to learn I would suggest reading up on common wiring practices and code before doing this work for hire. You're a builder? Hire an electrician because you have no idea what you're doing but you're selling this service. If you we're a DIY trying to save a buck then I would refrain from being so harsh. You're only hurting your customers and cheating licensed professionals such as myself out of work.
 
  #13  
Old 09-02-13, 11:45 AM
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The first picture

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is the first switch/box for the 3-way light. One traveler is removed in the picture but it is 12/3 from this switch to the second switch/box for the light. It is 12/2 coming into the box from the first switch(That's why I showed the first picture, to show where the power was coming from)

The second picture is the second switch/box for the 3-way light.

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12/3 coming in, black and red on the travelers, 12/2 going up to the light (3rd picture)

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Again, I have been struggling with it for a few days now so it looks messy but it will be neat again.
 
  #14  
Old 09-02-13, 11:47 AM
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We posted at the same time, but your schematic is good. If that is how things are wired, exactly, then all should be working. Just not seeing the 12-3 threw us off course a little. You are ensuring all your neutrals are connected throughout the installation? You said it was working, then stopped. What symptoms is it exhibiting now? Just not working? With wires extended from the box safely, use your multimeter to determine the hot wire is correctly connected to the black andonized screw of the switch, and that the traveler didn't sneak down there. Let us know.

You and Danny can't go to recess if you don't stop, OK?
 
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Old 09-02-13, 11:52 AM
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Im cool Danny... no hard feelings. Sometimes in forums like, its hard to get things across but I'm trying to clear any confusion as I go.

Also, this is where I will live. It's mine. My father and I have done about 70% of the work and have been involved in everything except the foundation/slab and stucco. We hired some framers, electricians, plumbers, and worked along side them as we went. It has been inspected and the inspector even commented on how clean the electrical work looked before the drywall.

We are building it with what we have trying to do it without a big loan so we count nickels. I'm pretty sure I have an understanding of basic wiring but there is always more to learn.
 
  #16  
Old 09-02-13, 11:53 AM
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Your hook is backwards.
 
  #17  
Old 09-02-13, 12:01 PM
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I checked the neutrals and they look good although I would like to use the meter to test them if it's possible.

The symptoms are that if I connect the common on the first switch, both traveler screws are immediately hot. (6 switches now) Tested with the pen tester. One the second switch, both traveler wires are hot and the black for the lamp is hot.

If I disconnect one traveler on the first switch, the first switch will control power to the light fixture and second switch.

Those are the only symptoms. Don't know what to test from here.
 
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Old 09-02-13, 12:04 PM
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thanks

lol... thanks man. Seriously. I can use all the help I can get. Which way are they supposed to go?
 
  #19  
Old 09-02-13, 02:18 PM
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The 3 way dimmer has a lead capped where both leads are travelers.
What 3-way dimmer? The only dimmer mentioned is in the second box from the panel feed, and controls from a single location.

This is what happens when builders do their own electrical work?
Is it? Or is it what happens when posts aren't read carefully?
 

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  #20  
Old 09-02-13, 03:24 PM
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I'm pretty sure I have an understanding of basic wiring but there is always more to learn>
A copy of Wiring Simplified should help with that. It's inexpensive, authoritative, comprehensive, continually updated to comply with each code revision, and it explains why, as well as how, residential electrical systems are built the way they are. You can sometimes find it in the electrical aisle at home improvement and hardware stores.

That said, the schematic you posted is one correct way to connect a pair of 3-way switches. It should be working, as Chandler said.

Your pictures aren't helping because they don't show us what we need to see: the wiring connections by wire and color. Posting descriptions and test results will help more. In fact, obtaining test results will help.

These are the testing tools I have... I have been using the pointer that just tests for power.
And it's been telling you you have power. It hasn't been telling you which wire you have power on because it can't distinguish that.

I would like to test for continuity to see if there is a short somewhere. Maybe a staple or nail??
You don't have a short. You have power and you aren't tripping the breaker. Don't waste any time on that and don't worry about it until and unless a symptom of a short appears.

I don't know how to do it exactly, but I believe the meter will let me.
The meter will let you test for which wire is hot and whether it has 120V line-to-neutral on it. That's what you need to know, not continuity.

If the first switch is one way, [with one traveler disconnected] the lamp wire tests hot, If I flip the switch on the first switch, the lamp wire tests off.
This is as it should be.

There is no light on it, just the 3 wires. I have not tried it with a lamp.
Do that now. Terminate the wires according to the schematic you posted and add a light bulb at the ceiling outlet. You can use a rubber lampholder for that.
 
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Old 09-02-13, 03:25 PM
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The symptoms are that if I connect the common on the first switch, both traveler screws are immediately hot. (6 switches now) Tested with the pen tester. One the second switch, both traveler wires are hot and the black for the lamp is hot
I thought we were passed this. Put your pen tester away. Give it a small vacation. From the way you described your wiring and again in that diagram you posted.....you ARE wiring it correct. If you put a hot wire on a common screw of a three way switch....both traveler screws CAN NOT be hot.

Did you put an actual light fixture in the circuit to test with at the ceiling box ? It can be anything....even an electricians chandelier.

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  #22  
Old 09-02-13, 04:18 PM
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Did you put an actual light fixture in the circuit to test with at the ceiling box ? It can be anything....even an electricians chandelier.
Thanks for posting a picture of the fixture I linked to.
 
  #23  
Old 09-02-13, 04:20 PM
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Problem solved

Thanks for all the help... you guys are tough!

I did use the meter to test it. I didn't know how to use it, that's why I was using the pen tester. Everything is right and works perfectly. Both switches control the light fixture on or off now.

Not to bring up the pen tester again, but the black wire still tests hot. Using the meter, it show hot and off but the pen tester shows hot all the time.

Not sure if it matters or not but I think I'm good to go now.

Thanks again.
 
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Old 09-02-13, 04:27 PM
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I till try a light, I don't have one yet. The reason I thought not having one transfer wire connected is that without it, the light wire wouldn't test hot if the switch was one way on the first switch. With both transfer wires connected, the light wire tested hot all the time.

Again... just explaining my trouble shooting methods for anyone else that has trouble with a 3-way switch.
 
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Old 09-02-13, 04:31 PM
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The symptoms are that if I connect the common on the first switch, both traveler screws are immediately hot. (6 switches now) Tested with the pen tester.
No, unless that switch is defective only one of the traveler terminals is hot at any time - and one of them is always hot. Your pen tester can't tell which is which.

On the second switch, both traveler wires are hot and the black for the lamp is hot.
Really? Is the wire to the lamp hot no matter which way the second switch is flipped?

If I disconnect one traveler on the first switch, the first switch will control power to the light fixture and second switch.
The first switch hot or not depending on which way it's flipped. The second switch will control the power to the light while that traveler is hot.

Here's a quick tutorial on 3-way switches:

3-Way Switch

A 3-way switch is a single-pole, double-throw switch. Single-pole means that only one "hot wire" is connected to it. It also has two other wires connected to it, and double-throw means that when you switch it, instead of opening and closing the circuit, a 3-way switch changes the connection of the "hot wire" back and forth between two other wires.

Those other two wires are called "travelers." They are connected, ultimately, to a second 3-way switch, and that second switch is connected to the wire that carries the power to your light. That's why, by installing a pair of 3-way switches, you can turn a light on or off from two different locations.

Internally, a 3-way switch looks like a "V". The point of the V is the terminal where the hot wire or the load wire -- the one going to the light -- is connected. The two traveler wires are connected to the two open points of the V. The point of the V is called the common, or point terminal. It will look different, usually because it will have a dark, almost black, screw. The open points of the V are called the traveler terminals, and they will usually have bright brass screws.

On one of the switches, the power coming from the panel is continuing on one of the two travelers to the second switch. If the second switch is not set to connect that traveler to its common terminal the light is off. If you flip either switch then both of the switches will have their common terminal connected to the same traveler, the power will go on to the light and it will come on.
 
  #26  
Old 09-02-13, 04:42 PM
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Thanks...

when I said they were both hot, that was according to the pen tester.

The meter shows only one hot at a time.

The pen tester shows the light wire hot
The meter shows it on/off depending on the switches.

I think I get the concept of a 3-way switch pretty good. What was throwing me is the lamp wire testing hot.

ASAP, I'll get a lamp to make absolute certain but the meter is testing everything OK.
 
  #27  
Old 09-02-13, 05:12 PM
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I think I get the concept of a 3-way switch pretty good. What was throwing me is the lamp wire testing hot.
It sounds like what was throwing you, in addition to not being entirely comfortable with 3-way switch function, was forgetting to flip the second switch and test again. That would probably have given it to you.

Glad you got it figured out. Amazing what you can do with a meter, isn't it?
 
  #28  
Old 09-02-13, 05:16 PM
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sure hope someone else can benefit from this someday

Better to learn from experience...Preferably somebody else's.

Thanks again!



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  #29  
Old 09-02-13, 05:21 PM
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So just to be clear, nothing would suggest a problem with the pen tester testing the wire hot all the time?

The meter checks and confirms that it is working properly, and most importantly it works with a light bulb.

I just don't know why it tests hot with the pen tester. If that's normal, and most people have said pen testers aren't the best tools to use for this, then ok.

If it doesn't seem normal... I need to find out why.
 
  #30  
Old 09-02-13, 06:53 PM
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The tick tracer will detect voltage induced over a space of several inches, so it is entirely possible it was detecting both wires hot, when in reality only one was hot, and the induced current was causing a false reading. I use one every day, just to detect the presence of voltage. Then I break out the meter and determine all the information, like you did regarding which one is hot.
 
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Old 09-02-13, 08:14 PM
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So just to be clear, nothing would suggest a problem with the pen tester testing the wire hot all the time?
There doesn't appear to be anything wrong with your pen tester, if that's what you're asking. The problem was that you were trying to use it to do something it isn't designed to do: Tell you which wire or terminal is hot.

As Chandler said, I use one every day. All day. It lives in my shirt pocket at work. I also carry two meters. If I need to know something more than "hot or not," I pull out one of my meters... usually the one that lives in my other shirt pocket at work.
 
  #32  
Old 09-02-13, 11:15 PM
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see guys... that's what has me confused. The pen tester is showing the black wire hot. It is about 3 feet from the switch/box so I don't think it would detect a live wire in the box. I can take the light off and see if there are any volts when the switch is off, but I don't think it showed any when I tested it.

So the problem isn't only which wire the pen was detecting inside the box... its that the black wire in the 12/2 up at the lamp location is still testing hot with the pen tester regardless of switch position.

I can understand it not being able to detect which traveler but I think the box is too far away to effect the reading on the lamp location.

The light works good... I've been using it for the past few hours.

If you guys think its alright, I'll leave it as a problem solved but I'd like to make sure.
 
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