3-way switch question

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  #1  
Old 09-02-12, 11:56 AM
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3-way switch question

I am replacing old switches and running into difficulty with getting the new switches to work.

We have a motion light off the back of the garage that has a switch in the house and a switch in the garage. It has been working fine until I started messing with it. The power comes into the switch in the house, out to the other switch then continues on to the light. It is not wired like a typical 3 way with a 14-3 between the switches. Here's a pic of the switch in the house:



The top wires are power coming in, the bottom is a single black wire that splits into 2 black wires before it goes into the wall. The white wires are tied together and I assume these 4 wires(2 black, 2 white) go to the other switch. The wire(s) go underground to the garage, more importantly under a sidewalk, so accessing them after this switch would be labor intensive and cost me a sidewalk.

Pic of the garage switch:
Back:


Front:


Only one wire(black, white) came into this switch and one went out to the light. The top terminals go to the light and the bottom terminal(marked "line") was a black wire coming from the house. The white wire with it was tied into another white wire in the double gang box. What's going with this mess?
 

Last edited by Nashkat1; 09-02-12 at 12:54 PM. Reason: clarification
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  #2  
Old 09-02-12, 01:50 PM
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Ignoring the SPST switch on the right in your picture of the duplex switch in the garage for the moment, a pair of 3-way switches must have three conductors run between the two boxes to work. In setups like yours, where the power comes into one box and the load is fed from the other box, one of those three wires is used to carry the ungrounded conductor, or neutral, from the panel feed to the load. That would appear to be
The white wires are tied together [in the box inside the house and] The white wire [that is] tied into another white wire in the double gang box.
The other two wires are the travelers. These are connected to the two (usually brass) traveler terminals on each 3-way switch.

The power from the panel is connected to the point, or common (usually black) screw terminal on the switch in the box with the power feed. The wire that carries power to the load is connected to the point, or common (usually black) screw terminal on the switch in the other box.

The top wires are power coming in, the bottom is a single black wire that splits into 2 black wires before it goes into the wall.
I'm not sure. The wires connected to the "top" of the switch appear to be connected to two brass screws. My first guess is that they are the travelers. The single black pigtail that is spliced to two black wires looks like the power coming in (and continuing on).

Only one [cable, with one black and one white wire] came into this switch and one went out to the light.
That's not enough cables, or wires. Please check again. With only those two 2-conductor cables, this 3-way system would never have been working fine.

Two questions: Is there a box between the switch in the garage and the light with wire fed into it? And, you say the switch box in the garage is a "double gang box." What is mounted in the second position in the box?
 
  #3  
Old 09-02-12, 02:16 PM
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It appears that there are two cables coming into the left side of the box in the house and these two cables have there wires spliced with a pigtail on the black feeding the common terminal on the switch. That would probably mean that one cable is power incoming to the box and the second is power going to the garage. The cable on the right is the switch travelers going to the garage.

At the garage there will be two cables, one has power (hot and neutral) and the other will be the travelers coming from the house switch. The garage light will be connected to the white of the power cable and the common on the switch. The black and white on the power cable will continue on to an "always on" receptacle.
 
  #4  
Old 09-02-12, 03:00 PM
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Thank you for the replies....I have been working on this for most of the day as it's tearing me apart as to why it doesn't work like it used to.

I found a junction box between the first 3 way switch and the garage. Both wires do in fact come into the garage, just at different points....I learn something new everyday about this place. I don't think the PO hired a professional for ANY work and I have tried to fix things as I find them. I am not a professional by any stretch of the imagination, but I will do my best to do it right. When I don't know, I seek help.

OK, so both 14-2 wires from the house switch come into the garage. One of those 14-2 wires has about 80V and one has 120V. I can only assume the 80V wire comes from the 3 way. Is that right?? That wire is extended to the garage 3 way switch. Currently, these wires are connected to the traveler terminals on the switch.

The other 14-2 wire powers everything else in the garage...multiple outlets, interior and new exterior lights not including the motion light.


The original double gang box in the garage had this switch(3 way on top and SPST on bottom) and an outlet. I added a pair of exterior garage lights, which started this whole fiasco. The original wiring was old and brittle, so I began replacing what I could with some 14-2 I had leftover from other wiring projects. I had a picture of the original garage switch box with all wires attached, but my daughter got a hold of my phone and well, you know the rest. I pulled everything out of that box, installed a triple gang box for the switches I need and also moved the outlet down under the switches and installed a GFI. The power for this GFI comes from the "other" 14-2.
 
  #5  
Old 09-02-12, 03:20 PM
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The other 14-2 wire powers everything else in the garage...multiple outlets, interior and exterior lights.
I believe that if you feed this "other" 14-2 cable into the box with the 3-way switch and the feed for the pair of exterior lights, and connect the neutral in it to the neutral feed for the exterior lights, then connect the hot feed for the exterior lights to the point screw on the 3-way switch, everything will work the way you want it to. You can cap off the hot wire in the "other" cable, or use it to feed other devices. It isn't needed for this.

Note that I said it should work. I didn't say it was strictly kosher. It isn't.

Two questions and a comment:

Is the circuit you're adding to with 14AWG wiring protected by a 15A fuse or circuit breaker, or by a 20A?

The splice for the two white wires, and the splice for the three black wires, behind the switch in the house, need to be redone as proper splices unless they are soldered connections, and maybe even then.

Is the power to the garage run in cables pulled through a conduit that is buried under a sidewalk, among other things? If so, what type of cable is it?
 
  #6  
Old 09-02-12, 03:38 PM
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Thank you for the tip...it must've been wired this way and when I pulled the wires out to run new, I probably overlooked this wire.

When you say,"point screw" on the 3 way, I'm assuming common terminal? Could I use a short jumper in the box from one of the switches hot terminal to the 3 way common?

Yes, this circuit has a 15A breaker.

The splices behind the house 3 way bothered me, so I removed the tape and bound them together with wire nuts. Is this sufficient?

The wires for the garage are under ground with conduit where they are exposed at the house exit point and garage entrance point.
 
  #7  
Old 09-02-12, 04:19 PM
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When you say,"point screw" on the 3 way, I'm assuming common terminal?
Yes. I try to remember to say it both ways. I regret the lack of clarity.

Could I use a short jumper in the box from one of the switches hot terminal to the 3 way common?
The 3-way in the house had a hot feed through the pigtail off the power-in-power-out splice. The 3-way in the garage needs to have the wire that will feed hot to the load - the lights - connected to the common, or point, terminal --not a hot wire.

Yes, this circuit has a 15A breaker.
OK, good.

The splices behind the house 3 way bothered me, so I removed the tape and bound them together with wire nuts. Is this sufficient?
If you actually spliced the wires by twisting them together, clockwise, about three times, and then trimmed the end and twisted a wire nut on, then yes.

The wires for the garage are under ground with conduit where they are exposed at the house exit point and garage entrance point.
What type of wire - er cable - is it?
 
  #8  
Old 09-02-12, 05:02 PM
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I read your response a few times and I'm still lost. I'm sorry...I apologize for not using the correct terminology ahead of time.

Also, I have yet to learn how this forum works with replying to a response, this is a bit different than my other forums that I frequent.


Two 14-2 wires come into the garage, one is the traveling wires for the 3 way and the other powers everything out there. The "other" wire has 3 other wires connected to it for the door opener, the new GFI and the old outlets. I jumped power for the interior lights and my new exterior lights from the GFI since it was immediately below the switch location.

You're saying I need another wire from the junction box tied into the "other" wire and run it to the 3 way switch box. Correct? Where do they, white wire and black wire, go? Where do I connect the white and black wire leading to the motion light?
 
  #9  
Old 09-02-12, 05:27 PM
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You're saying I need another wire from the junction box tied into the "other" wire and run it to the 3 way switch box. Correct?
Yep.

Where do they, white wire and black wire, go?
The white wire connects to the white wire leading to the motion light. The black wire can just be capped off, unless you need power there for something else.

Where do I connect the white and black wire leading to the motion light?
The white wire leading to the motion light connects to the white wire in the extension of the "other" cable. The black wire leading to the motion light connects to the point, or common, terminal on the 3-way switch.

Two 14-2 wires come into the garage, one is the traveling wires for the 3 way and the other powers everything out there.
Those aren't wires. they're cables. They have wires inside them.

The question still is "What type of cable?" Type NM (Romex), Type MC, Type UF, or...?

A picture would help.
 
  #10  
Old 09-02-12, 06:02 PM
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[HR][/HR]That is perfect, thank you!!!!

I'm sorry, I forgot to say the cables exiting the house and entering the garage are type UF and they are enclosed in conduit at least into the ground. The conduit very well may run from the house to the garage under ground as the run is approx 6', but I won't know until I break up the concrete path next summer.
 
  #11  
Old 09-02-12, 06:33 PM
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the cables exiting the house and entering the garage are type UF and they are enclosed in conduit at least into the ground.
That is perfect, thank you!
 
  #12  
Old 09-02-12, 06:44 PM
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