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skip67
Three way switch for kitchen

My question is about three way switches. I live in a two bedroom apartment and my main entrance is in the kitchen.The problem is the light switch is on the otherside of the room.I do most of the repairs in the building, however I have never put a three way switch in before and the diagram that came with the new switches sujest I may have to add some more wiring.
[THE DIAGRAM SHOWS ONE SWITCH WITH POWER COMING IN AND GOING OUT TO THE OTHER SWITCH AND POWER GOING FROM THE SECOND SWITCH TO THE LIGHT.][THE PROBLEM IS THE NEW SWITCH AT THE ENTRANCE DOES NOT HAVE A POWER SOURCE ONLY 12/3 WIRE I PUT THROUGH THE HAUL
WALL TO THE OTHER SWITCH WHICH HAS POWER THAT GOES TO THE LIGHT. I CAN NOT RUN ANYMORE WIRE IN THE WALL, BECAUSE NEW DRYWALL HAS BEEN PUT UP. I CAN NOT RUN A WIRE FROM LIGHT TO THE NEW SWITCH, BECAUSE OF CEILING SPACE. PLEASE HELP ME FIGURE THE SAFEST WAY TO DO THIS PROJECT. Please do not send me ideas that might work or THAT are ???? with code. Other people live in this building and I would rather go without the extra switch than take a chance on a fire. My youngest brother died in a fire three years ago. Thanks for your help. Skip

JLMCDANIEL
Re: Three way switch for kitchen

I'm not quite sure exactly what you have in place so I'll try to explain 3-way switch wiring.
You need two 3-way switches. Each switch have 2 screws on the top and one on the bottom. You need to be able to connect the two screws on the top of switch one to the two screws on the top of switch two, these are called travelers. On switch one you hook the supply hot wire to the bottom screw, the bottom screw on switch two is hooked to a wire going to the light, the other side of the light is connected to the supply neutral. See drawing.

Jack

Attachment: 
calcats
Re: Three way switch for kitchen
JLMCDANIEL wrote:

I'm not quite sure exactly what you have in place so I'll try to explain 3-way switch wiring.
You need two 3-way switches. Each switch have 2 screws on the top and one on the bottom. You need to be able to connect the two screws on the top of switch one to the two screws on the top of switch two, these are called travelers. On switch one you hook the supply hot wire to the bottom screw, the bottom screw on switch two is hooked to a wire going to the light, the other side of the light is connected to the supply neutral. See drawing.

Jack

Jack, this picture is undoubtedly the clearest wiring of a 3-way switch I've ever seen. I'm going to copy it and keep it in my wallet. Thanks.

Calcats ;)

wolfbeater85
Re: Three way switch for kitchen

Hi Skip. My name is Trev and I'm a 3rd year electrical apprentice. That being said, If I understand your situation correctly then you yes you can have your 3-ways working properly with what you have installed. Just to verify I am under the impression that your first switch box contains the following: a 12-2 or 14-2 with power and neutral, a 12-2 or 14-2 leading to your light fixture(switch leg), and a 12-3 leading to the second switch box. The second switch box contains only the 12-3 leading back to the first switch box. If this is the case here is what you want to do. Shut of the power to the circuit at the panel and verify all wires are dead with a working voltage tester. Starting with the first switch box, wire all the grounds together being sure to also ground your switch. Wirenut the incoming neutral to the neutral of the switch leg. Wire the incoming hot to the hot screw of the 3-way switch. The hot screw should be identified by a different color than the other 2 screws. Now choose two of the 3 wires in your 12-3 to be used as travelers, lets say for example black and white. Wire each of these to a traveler screw. All you should have left is the red wire from your 12-3 and a black wire leading to the light fixture. Wire nut them together to complete the first switch box. Moving on the the second switch box containing just a 12-3. Wire the red to the switch leg screw (again it should be a different color. Wire the remaining white and black wires each to a traveler screw. Don't forget to ground everything. You're all done. Good luck, -Trev

JLMCDANIEL
Re: Three way switch for kitchen
wolfbeater85 wrote:

Hi Skip. My name is Trev and I'm a 3rd year electrical apprentice. That being said, If I understand your situation correctly then you yes you can have your 3-ways working properly with what you have installed. Just to verify I am under the impression that your first switch box contains the following: a 12-2 or 14-2 with power and neutral, a 12-2 or 14-2 leading to your light fixture(switch leg), and a 12-3 leading to the second switch box. The second switch box contains only the 12-3 leading back to the first switch box. If this is the case here is what you want to do. Shut of the power to the circuit at the panel and verify all wires are dead with a working voltage tester. Starting with the first switch box, wire all the grounds together being sure to also ground your switch. Wirenut the incoming neutral to the neutral of the switch leg should be neutral going to light. Wire the incoming hot to the
hot screw of the 3-way switch. The hot screw should be identified by a different color than the other 2 screws. Now choose two of the 3 wires in your 12-3 to be used as travelers, lets say for example black and white should use red and white. Wire each of these to a traveler screw. All you should have left is the red should be black wire from your 12-3 and a black wire leading to the light fixture. Wire nut them together to complete the first switch box. Moving on the the second switch box containing just a 12-3. Wire the red should be black to the switch leg screw (again it should be a different color. Wire the remaining white and black should be red and white wires each to a traveler screw. Don't forget to ground everything. You're all done. Good luck, -Trev

Just a couple of correction providing you assumtions are correct and the white lead in the 12-3 should be marked with heat shrink or black electric tape to indicate that it is not a neutral. If wolfbeater85's assumptions are correct see drawing below.
Jack

wolfbeater85
Re: Three way switch for kitchen

Thanks for the correction Jack. I have very little residential experience, I'm still learning the conventions and industry standards...among other things.

Fencepost
Re: Three way switch for kitchen

You might also consider a wireless remote switch. The main unit is a direct replacement for the existing switch, and you have a wireless transmitter that you can place anywhere else in the house. It's a quick, easy way to overcome the mysteries of the 3-way switch. Nevertheless, I'll try to explain how I would do it, and hopefully not add confusion.

In this example, I will assume that you can run a 14/3 (15A circuit) or 12/3 (20A circuit) wire from the existing switchbox. Similar to JLMcDaniel's diagram. My method works whether you have one or two cables coming into the switchbox. Switch "A" is at the existing location; switch "B" is at the new location.

First, the only existing wires you will work with are the ones that connect directly to the existing switch. You shouldn't need to mess with the other wires in the box.

Connect one of the two existing wires to the dark-colored screw of switch "A". Connect the black wire of the new cable to the other existing wire at switch "A". Connect the remaining two wires (red & white) to the remaining screws -- it doesn't matter which to which.

Now at switch "B" connect the black wire of the new cable to the dark-colored screw on the switch. Connect the red & white to the other screws.

As others have mentioned, mark the new white wire with black or permanent marker. This is necessary to make it clear to future "electricians" that it's not a neutral. (In electrical wiring, white always indicates neutral and green always indicates ground. It seems like gray might mean something, too, but I don't remember. All other colors may be used for everything else and should not be used for neutral or ground.)

JLMCDANIEL
Re: Three way switch for kitchen

Actually the drawing I did works if there is 2 cables or one in the original box. The switch doesn't care if the power wire is through the box or from the light or if the common is in the box or the light fixture.
Jack

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