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questions about wiring for several 3-way switches in 2x4 framing

questions about wiring for several 3-way switches in 2x4 framing

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  #1  
Old 12-14-15, 08:07 PM
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questions about wiring for several 3-way switches in 2x4 framing

Hi everyone.

I am looking for help with wiring for an unheated mudroom. I had an unheated 4x9 feet (small) porch and we just built an exterior wall with a door and a window. I would like to add one 3-gang box for light switches, one power outlet with 2 sockets under the window, one external light, and an external doorbell. The framing is 2x4, the floor is concrete slab, no access from basement. Please see attached 5 photos of the area and one for a proposed circuit.

The circuit: I currently have a foyer light and a mudroom light. I want to add one exterior light. I currently have 3 one-way switches in the foyer. I would like to replace them with 3 two-way switches and add another 3 two-way switches in the mudroom, so all 3 lights could be controlled either from the foyer or from the mudroom. I currently have 14-3g running from foyer light to the foyer switches (4,5,6), and 14-2g from switches (4,5,6) to the mudroom light. I want to keep the existing 14-3g for the common and travelers 1 and 2, use existing 14-2g for travelers 3 and 4 and add other wires as shown on the last picture. I will run power 14-2g from the foyer light to the mudroom light, then to the new box on the new wall, and then to the outlet. So, for this circuit I need to run two 14-3g's, two 14-2g's, and one doorbell wires from the attic down to the new box. Please criticize the circuit if you see how to improve it. In the foyer light I have 2 4-wire nuts and 3 2-wire nuts. Looks like a lot. Do I need a junction box for this?

The problem is how do it properly. Unfortunately, I cannot drill through the header because I was asked to write on the construction plan that I am not touching the header. The top plate of the framing is proud with respect to the header by 9/16'' (see last photo). I am thinking about running a conduit to the 3-gang box, putting all wires into it, driving wires into the 3-gang box, and then making connections for the outside light, power outlet (and doorbell?). It would be very nice if I could notch the top plate of the framing by 9/16'', and run wires through a rectangular steel tubing (1/2''x something like 1''), and attach that tubing to the vertical stud. I do not know if it up to code or not, and how to make proper connections between the tubing, switch box, light box, and doorbell and whether I can use a rectangular conduit.

I could run two round 0.5'' conduits, but I don't know if I can fit 14-3+14-2 in one conduit and 14-3+14-2+doorbell into another. I also don't know how far apart the conduits should be (do I need to run them along different studs?) and how to make connections to the switch boxes.

The power outlet seems easy, because I should be able to run the wire down from the box and drill through the centers of window cripples. Is it what I should do?

The cleanest solution seems to be to run all wires through 0.5''x1'' rectangular steel tube, but I don't know how to connect things and whether it is up to code.

I am in Falmouth, MA, if that matters.

Thanks a lot.

Pictures:

http://s21.postimg.org/rmpmiugs7/IMG...214_191407.jpg
http://s21.postimg.org/o5s5tm73r/IMG...214_191412.jpg
http://s21.postimg.org/owkvze9h3/IMG...214_191419.jpg
http://s21.postimg.org/9y2h4yuev/IMG...214_191425.jpg
http://s21.postimg.org/ma0s4psvr/IMG...214_191537.jpg
http://s19.postimg.org/ki9c6iyhv/circuit.jpg
 
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  #2  
Old 12-14-15, 08:30 PM
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I approved your post. There shouldn't have been an issue as your pictures are links but the spam reduction system thought your links were spam.

A picture looking at the whole wall would be good. You could drill under the window to get power where you need it. I'm still reading your post. A bit confusing.

In the foyer light I have 2 4-wire nuts and 3 2-wire nuts. Looks like a lot. Do I need a junction box for this?
All wiring and connections must terminate in junction boxes.


Why are you running all the three way switch lines thru the fixture boxes ?
You are creating too many splices.
 
  #3  
Old 12-15-15, 07:11 AM
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Dear PJmax,

thank you for quick reply.

Sorry for being confusing. I said I have one-way switches and want two-way. I meant I have two-way, and I want three-way switches. Three pairs of three way switches so I can control 3 lights from 2 rooms, foyer and mudroom.

Here are 3 more pictures:
http://s30.postimg.org/ppsuwfhy9/IMG...215_064303.jpg
http://s30.postimg.org/z04yzyso1/IMG...215_064330.jpg
http://s30.postimg.org/xjtghtpr5/IMG...215_064353.jpg

It is hard to take the whole wall picture, because the mudroom is less than 4' deep, I can't stand back far enough.

1) Nuts in the foyer light box: I meant to ask whether I should have a separate junction box to twist 4+4+2+2+2 or should I try to stick them into the light box as they are now? (probably not, because the volume would be too small for so many wires, right?)

2) Yes, I agree that splices of travel wires are not needed in the foyer and mudroom fixture boxes. However, I have a few concerns. If I run travel wires directly between switches 2-5, and switches 3-6 I would need to use a single 14-1 wire for the common between the foyer light and switch 6. I would also need to use two single 14-1 wires for common returns from boxes 2 and 3 to the lights. I've never seen that. Wouldn't it be easier to stick to 14-2 and 14-3 wires? I already have 14-3g between foyer and switch 6, I also already have 14-2 between mudroom and switch 5, and I have common connected between 4,5, and 6. I only need to add 14-3's from lights to switches 2 and 3, add 14-2 between 4 and 1, and extend the 14-2 power line to mudroom, new box, new outlet, and new light. If I use 14-1's that will increase the number of cables entering the new 3-gang box, which is already a lot.

3) I would prefer not to run the wires laterally from another switch. It is much easier to run them up into the attic and then down to the new box. The area behind the (storm) door is finished, I would have to take the whole drywall apart. Also, there is a door (which was external before this wall was built), the framing makes it difficult to drill sideways towards existing foyer box. I still need to connect lights to the new box, so I probably cannot run these wires to the foyer box first and then laterally to the new box, because there will be too many wires in the foyer box. I will also have to drill through a quadruplet of 2x4s (2 cripples and 2 studs) if I want to bring wiring from the right, which will be difficult. On another hand running wires straight down from the attic is easy, the problem is how to make it code compliant. As you can see, I can use as many as 4 studs and run 4 individual cables (but I need 5 with doorbell), make 4 notches in the top plate, and then run wires laterally. But, I think, I still need some kind of conduit because I am less than 1-1/4 from the stud face.

I am sorry it is confusing. I am trying to understand it myself.

Thanks a lot for your help.
 
  #4  
Old 12-15-15, 07:39 AM
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It would be easier to understand if you inserted you images into the posts. Having to click on that many links it is hard to keep focus. Reduce your photos to a width of 900px or less and they should insert okay. http://www.doityourself.com/forum/li...rt-images.html
 
  #5  
Old 12-15-15, 08:06 AM
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Ray2047,

thanks.

All pictures are inserted.

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  #6  
Old 12-15-15, 11:43 AM
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Thanks for the pictures.

Terminology: 2-way switch is what they call a 3-way switch in the UK. It has no meaning in the U.S. For a switch that just works from a single location call it a "single location" switch. My made up terminology but others will understand.

Have you considered using surface raceway (AKA Wiremold). If ascetics aren't critical you could run in the stud cavities where possible then where needed bring the cable out to a surface mounted box and run in surface raceway to the next available wall cavity.

You would run what cable you could in the cavity and just let a few inches hang out where the obstruction begins. Then hang your Sheetrock bringing about 10 inches of cable through it. After the Sheetrock is up you would mount a surface box over the cable coming through the Sheetrock. Connect your surface boxes with wire mold using THHN wire in the Wiremold raceway.
 
  #7  
Old 12-15-15, 01:02 PM
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Ray2047,

thanks. Raceway is a good suggestion. But the looks are kind of important too. This is the main entrance to the house. It would be nice to have all wires hidden. If nothing else is possible I will try raceway.

What do I do inside the cavity? Can I just stack all wires together, use 3M wire separators (separating wires laterally) and run them vertically along the center line of the right stud (closest to the new window)? And then just route them into the 3-gang box?

When I hit the top plate of the 2x4 framing, can I make a notch 9/16'' deep and run the wires straight up into the ceiling, in front of the header? To protect them I can get a 0.5''x1''x height (about 8'') stainless steel pipe and fasten it to the header. Alternatively, I can cut out 2 wooden "shims", 9/16'' thick, fasten them to the header so they are flush with the framing, run all wires in between and cover all that by 1/16'' steel plate or several plates, either along or across from the bottom of the framing top plate to the ceiling. Would any of this be up to code?

In either case, with the raceway or without by how much should I separate wires running vertically along the header? Should I drill 5 holes for 5 cords in the ceiling, or can I run several (how many?) wires through a single hole?

Please see the drawing. Would this be up to code?

Thanks.

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  #8  
Old 12-15-15, 04:49 PM
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Unfortunately, I cannot drill through the header because I was asked to write on the construction plan that I am not touching the header.
I'm still not understanding why that couldn't be drilled. It's only a 4' wall.... there should be minimal load on it. What is it..... two 2x12"s nailed together ?

Hmmmm..... I guess if it was only three inches thick it would be tough to drill. As it is you'll have to shim it out for a place to fasten the sheetrock to.

Your idea looks to be ok. I can't say what an inspector would say as each one has his own ideas. You will need to use a continuous nail plate and the wiring will also need to be protected where it's drilled up. It needs to be protected anywhere a nail could hit it.

Let's see what the other guys think.
 
  #9  
Old 12-15-15, 06:35 PM
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Pete,

Thanks. The header is a double 2 x something, probably 10, not 12. I did not measure, because it goes up into the attic. The building commissioner asked me to write on the plan that I am not modifying the existing header. Even if I ask for deviation from the plan it would be hard to drill it. If I drill through the center of the 2x4 top plate, the hole will be too close to the side of the header. If I aim to drill through the center of the 2'' wide header, I will be closer than 1-1/4'' to the side of the top plate. The header supports at least 10' (not 4'), the length of the mudroom. It might extend further into the foyer beyond switches (4-6). I did not check. Drilling closely spaced 5 holes in the 2'' load-bearing header sounds dangerous.

I would be happy to put a single piece 1/16'' stainless steel plate over that area (if other experts think it is ok too), but I need more specific details and guidance.

I could use cable stackers like these Cable Stacker, Pack of 15, but I read online that some inspectors complain that these stackers are not designed to support the weight. What hardware do I need then? I can't fasten all cables together to the 2x4.

Also, how do I protect these wires from nails? Nails are all over the place in the sheathing, as you see in the pictures. Should I cover all these nails with some caps? What should I use to space wires behind the proposed steel shield? Should I, after all, drill 5 separate holes, or can I run a few wires through the same hole?

Will putting 9/16'' shims and nailing or screwing a plate through them to the header be ok?

Thanks.
 
  #10  
Old 12-16-15, 10:10 PM
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I would not approve your circuitry.

The neutral or the live feed in a switch loop is required by code to be in the same cable or conduit as the switched wire. Separating these wires in different cables that go to different boxes can cause strange electrical effects (usually incurable noises) in electronic devices (e.g. a stereo system), troubles with carrier current controls, trouble with AFCI and GFCI breakers false tripping, and extra damage if lightning strikes the power lines or a short circuit occurs.

A short circuit in a normal circuit creates a momentary large magnetic field, but it is confined to the space between the wires in the cable or conduit. But if the travelers do not follow the same cable the neutral or the hot feed is in, then the large magnetic field created by the short circuit is created in ALL of the space between these cables. This can magnetize objects (e.g.watches, floppy discs, and credit cards), or even throw small metal objects off of shelves.

In addition, the new code requires a neutral to be present in each switch loop box, so that electronic switch devices that need a neutral can be used at a later date.

Essentially, the current that powers any electrical load must flow in both directions in the SAME cable or conduit run all the way from the load center to the load.

Thus, the neutral should be following the travelers wherever they go.

You should run a 12/2 to the first switch box. Then run three 12/3 cables to the second switch box (travelers and neutral) for each light. Do NOT connect the neutrals for the three lights to each other in the second box (Doing so causes false tripping of AFCI and GFCI.breakers). You can connect the grounds together provided the three cable runs closely parallel each other. Then run a 12-2 to each lamp from the second switch box.
 

Last edited by MidiMagic; 12-16-15 at 10:36 PM. Reason: typos
  #11  
Old 12-17-15, 07:15 AM
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MidiMagic,

these are great points. Thank you!

The circuit you suggest requires me to run 5 cables along the right stud (3x14-3s between switches and 2 14-2s back to the lights), and 2 cables along the left stud (to the outside light and low voltage doorbell). I bought Gardner Bender stackers from Lowes, but they only accept 4 cables. How should I position these 7 cables along the studs? Also, should I make 6 separate holes in the ceiling?

Should I just terminate neutrals in the second box with wire nuts? Should I connect all 4 neutrals (incoming at 3 outgoing) together in the 1-st box?

Thank you.
 
  #12  
Old 12-17-15, 07:18 AM
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Each neutral in the second box should be spliced and continue to its respective 14-2 to the light. Right?
 
  #13  
Old 12-18-15, 07:57 AM
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The proposed circuit is too complex, I think. Too many wires. I eliminated one 3-way switch for the foyer and updated the circuit. Please make your suggestions and criticize. Would you approve it?

I don't touch the foyer light circuit, run new power to the new switch 2, run 2 new 14-3g's, but wire the two lights in the "opposite" direction.

Now I can run 4 new cables, 2x14-3s and 2x14-2s, in the 4-slot stacker along the right stud, and staple the only low voltage doorbell wire to the center of the left stud.

I have a 16GA 18x8 inches steel plate from Lowes which I plan to cut to size to cover wires along the header. Is it ok?

Thanks.

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  #14  
Old 12-20-15, 08:40 PM
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I can't tell where neutral wires are connected together and where they are just crossing on the diagram.

Also, why is one 14-3 cable going through the new power outlet box?
 
  #15  
Old 12-23-15, 05:56 PM
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I updated the diagram. Thanks.

14-3 wire is not going through the box. The neutrals are connected as shown by blue fat dots. There are 2 nuts holding neutrals in each box.

I also found an existing 14-2 wire going out of 3-5 box into the basement, which was resting on the sill un-insulated (not good). The wire was connected to the switch 5. I built a new outlet in the basement and attached the wire as shown.Name:  mud_room_3_2_circuit_2.jpg
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  #16  
Old 12-28-15, 05:36 PM
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We just passed the framing inspection. The idea with this circuit, steel plate covering the wires along the header, and cable stackers worked out well. Thanks a lot for your help.
 
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