Miswired 3-way switch

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Thaddeus

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Location
Pearisburg, Virginia, USA
A 3-way lighting circuit has been run incorrectly in NM 12/3. Drywall now covers the NM. Can you think of a clever way to recover from the error, without cutting the drywall?

Application: Residential.

Details: NM 12/3 runs from (a) panel to (b) switch to (c) light to (d) light to (e) switch. The second switch is unfortunately last in the chain.

I can think of no way to finesse this. Can you?

Does someone manufacture an electronic 3-way switch which can work in this geometry without the extra wire?
 
Dennis Alwon

Dennis Alwon

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Sierrasparky

Sierrasparky

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Electrician ,contractor
Almost every switch manufacture makes something that will work.
Lutron-
Leviton- Vizia RF
Cooper/eagle
Ge/Iris - z wave 3 way kit no programing necessary
 
Dennis Alwon

Dennis Alwon

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Why a 12/3 from the panel. The setup as I understand it will not work unless you use the wireless system or Pico type system...
 
kwired

kwired

Electron manager
Location
NE Nebraska
Other then the code requirement to have a neutral at the end switch, operational wise all you need is to somehow get one more wire between the two lights and it can work. More details on construction methods that are between the lights is a must before many suggestions have much validity.

If it is easier to get another 3 wire cable between the two switches one could make that work as well.

One could make it work as is - but it requires setting up as an old "Chicago" three way circuit found in older wiring systems, which is not code compliant anymore.
 
Little Bill

Little Bill

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Tennessee NEC:2017
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Just omit/don't use one of the 12-3 conductors, either red or black from the panel to the first switch
In first switch location put in a Lutron 2-button RF switch LUT-PD5SDVWH
Treat the first switch as a SP using just line & load & again omitting the same conductor
At the lights, use the conductor you chose for the line and the white for neutral

At the second switch just cap off ALL the wires

Put in the Lutron PICO that Dennis posted but you will need the adapter plate
Lutron PICO-WBX-ADAPT Pico Wallplate Bracket
in order to mount it in a box

Yes these Lutron products take a Decor switch plate. You can use any Decor or Lutron makes one that is screwless
Lutron CW-1-WH 1-Gang Claro Wall Plate, White

This just lets you use one wired switch/controller and any other switches are wireless.
The "master" just receives an RF signal from the Pico to operate the lights.
 
ActionDave

ActionDave

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Thaddeus said:
Details: NM 12/3 runs from (a) panel to (b) switch
Click to expand...
Huh? Why? What is connected to what in the panel? What is connected to what at the first switch?

to (c) light to (d) light to (e) switch. The second switch is unfortunately last in the chain.
Click to expand...
This part sounds like a dead end three way, which is fine.
 
kwired

kwired

Electron manager
Location
NE Nebraska
kwired said:
Other then the code requirement to have a neutral at the end switch, operational wise all you need is to somehow get one more wire between the two lights and it can work. More details on construction methods that are between the lights is a must before many suggestions have much validity.

If it is easier to get another 3 wire cable between the two switches one could make that work as well.

One could make it work as is - but it requires setting up as an old "Chicago" three way circuit found in older wiring systems, which is not code compliant anymore.
Click to expand...
Never mind on the chicago three way - it would still need one more wire between lights to work.
 
readydave8

readydave8

re member
Location
Clarkesville, Georgia
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electrician
Thaddeus said:
A 3-way lighting circuit has been run incorrectly in NM 12/3. Drywall now covers the NM. Can you think of a clever way to recover from the error, without cutting the drywall?

Application: Residential.

Details: NM 12/3 runs from (a) panel to (b) switch to (c) light to (d) light to (e) switch. The second switch is unfortunately last in the chain.

I can think of no way to finesse this. Can you?

Does someone manufacture an electronic 3-way switch which can work in this geometry without the extra wire?
Click to expand...

Are you fixing someone else's mistake? If so drywall removal is just part of the cost of solution to problem, paid by customer.

Are you fixing your own mistake? If so drywall removal is just part of the cost of solution to problem, not paid by customer.
 
G

gar

Senior Member
Location
Ann Arbor, Michigan
Occupation
EE
150807-2346 EDT

The following is a logical way to accomplish the goal, but I don't suggest that it be used.

Wire the two lights in parallel across white and black. White is a solidly connected neutral, no switching in the neutral path. At the far end is a SPST spring return to off pushbutton wired between neutral and the red wire. Another similar pushbutton is at the beginning end, and wired the same.

At some convenient location that is accessable is located a single pole stepping relay with a low voltage coil, possibly 6 V. The relay single pole contact is used to switch the black wire (hot) to the lights. A small power supply is used to power the relay coil, one side to neutral, and the other to one end of the relay coil. The other relay coil end goes to the red wire.

This is only presented as a solution for a method to meet the requested challenge.

.
 
Sierrasparky

Sierrasparky

Senior Member
Location
USA
Occupation
Electrician ,contractor
gar said:
150807-2346 EDT

The following is a logical way to accomplish the goal, but I don't suggest that it be used.

Wire the two lights in parallel across white and black. White is a solidly connected neutral, no switching in the neutral path. At the far end is a SPST spring return to off pushbutton wired between neutral and the red wire. Another similar pushbutton is at the beginning end, and wired the same.

At some convenient location that is accessable is located a single pole stepping relay with a low voltage coil, possibly 6 V. The relay single pole contact is used to switch the black wire (hot) to the lights. A small power supply is used to power the relay coil, one side to neutral, and the other to one end of the relay coil. The other relay coil end goes to the red wire.

This is only presented as a solution for a method to meet the requested challenge.

.
Click to expand...

Very creative,
Why not use a setup that is listed for the purpose.
Use a Zwave or other power and neutral at both ends per code and be done. 45 bucks in parts
Why make it complicated.
 
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