Home>Discussions>ELECTRICAL & LIGHTING>3 Switches & 2 Lights - possible?
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Michael Mc
3 Switches & 2 Lights - possible?

Current situation: Switches at bottom and top of staircase control light fixture in upper hallway.

My wife would like: Another light added (no problem) and another switch added near the bedroom doorway (opposite upper landing switch).

How would I go about wiring three 3-way switches to control the upper hallway lights? In all my books, I can find no method of doing this, just the usual 3-way switch wiring. :confused:

kentvw
Re: 3 Switches & 2 Lights - possible?

This should get you heading in the right direction.

http://www.wfu.edu/~matthews/courses/p230/switches/SwitchesTut.html

Blue RidgeParkway
Re: 3 Switches & 2 Lights - possible?

you'd need to create a 4-way switch loop. you'll be able to reuse the two existing 3-way switches along with a 4-way switch.

since there are several possibilities as to your existing wiring this page is a very good place to start that includes specific instructions for a variety of wiring situations.

link: http://www.selfhelpandmore.com/switch-outlet/4-way/

good luck

JLMCDANIEL
Re: 3 Switches & 2 Lights - possible?

This is a schematic drawing of how 3 way and 4 way switches are connected. The colors do not match your wiring but was done for clarity in following the line. There may be intermediate connections in your wiring also not shown.Ground has been omitted for simplicity

Each 3 way has a common and 2 traveler connections, a 4 way has 2 travelers in and 2 travelers out. One 3 way common is connected to power, the other 3 way common is connected as the hot to a light or lights. The 2 travelers on switch 1 are connected to the travelers on switch 2.

To add a 4 way, you break the connection of the travelers to one switch and connect those wires to the 2 traveler in posts on the 4 way. The 2 traveler out terminals are then connected to the wires that go the the 2 traveler screws on the other switch. This break in the travelers can be made any where along the length of the travelers.

In you particular case the easiest way may be to run a 4 cond + ground from the upstairs switch over head and down to the new switch location. Disconnect the two travelers from the upstairs switch, connect 2 of the 4 conds. to the traveler screws and the other 2 wire nut to the 2 wires you had just disconnected. Keep the paired. Then connect the wires from the upstairs switch to one end of the 4 way and the other 2 wires to the other end of the 4 way.

Jack

Michael Mc
Re: 3 Switches & 2 Lights - possible?

Kent and BlueRidge, thanks for the links! Now I've got something to read while working (instead of doing actual work at work).

Jack, thanks for the diagram and discussion - they really helped get my mind around the problem. Guess I ought to spend more time in the electrical aisle of the home store... did not know there was such a thing as a 4-way switch. Not discussed in any of my books, either.

I wonder if we're related... same last name. :)

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