ECN Forum Forums General Topics of the Trade General Discussion Area 3-Way Challenge

I recently had to re-wire a three-way switch. What I found on arrival was that when the first 3-way was down, the second 3-way would turn the fixture on and off.

When the first 3-way was up, the fixture would come on and stay on regardless of the position of the second 3-way.

There was nothing unusual about the wiring: Feed at first switch; 12/3 carrying the neutral and two travelers to the fixture; neutral ties to the fixture; 12/3 continuing travelers to the second switch and carrying switched conductor back to fixture from second switch.

Both switches had cracked casings so I replaced them both without paying attention to how they had initially been wired, but afterwards got to thinking about it:

How is it possible to wire a switch so that it will not turn off a light? I can't come up with an answer, can you?

-John

Hi,
There is only one way this can happen.

The switches WERE MISWIRED when you got there...unless the switch is damaged..

look at this: http://www.lowes.com/lkn?action=how... =RightNavFiles/rightNavHowTo#wiring1

Heres what you do..

find where the power comes in...AT THE SWITCH..SW 1..

find/identify the HOT/FEED conductor that goes to the light..this is the COMMON..


then identify two wires as travelers..make sure toi keep them on the same corresponding brass/white scres between the sw1 & sw2

the hot/feed (common)goes to the BLACK screw on one switch for the POWER IN.. SW 1

the supply (POWER OUT) to the LIGHT goes to the OTHER black screw (common) on the OTHER switch.. SW 2

connect the neutral at the light ONLY..and the feed from the sw 2 to the light..

do that and it has to work!

anything else and it wont work properly!

hope that helps..

good luck..

regards

greg


[This message has been edited by mustangelectric (edited 03-17-2005).]

Mustangelectric,

I appreciate your help, but you misunderstood my question: After I replaced the switches, everything worked properly, I was simply wondering how in the world the first yahoo managed to wire them so that the light couldn't be turned off from one of the switches.

-John

Hi,
WHO KNOWS! I have seen this condition many times from home owners or someone else who meant well but once they took the wires apart they realized they did not know what wire went to what..

it was always a simple matter to swap a couple wires...charge them and get some glory!

Glad you fixed it!

thats my best guess!

-regards

greg

Hot - traveler reversed on power side of the circuit.

So... while on the subject. Heres a good 3-way puzzler. How do you make a 2 single pole 120v switches on 2 different services in the same building act as a 3-way for 2 seperate sets of lights? I just did this the other day.

Hi,

e57: You said: "How do you make a 2 single pole 120v switches on 2 different services in the same building act as a 3-way for 2 seperate sets of lights? I just did this the other day."

first question..WHY?

ok i will take your bait!-

first we have four terminals to work with..they are all common...

take the hot in and go to one switch...from that same term....go to the other switch and term on that switch...
the two remaining terms run to the light.

i am not sure how you would do that with two seperate feeds...i gues L1 goes to one switch and L2 goes to the other switch then to the lights?

-regrds

greg


[This message has been edited by mustangelectric (edited 03-17-2005).]

Hi,
Heres another one for you to chew on:

How do you wire up a 2 pole three wire dryer?

-regards

greg

Hi,
to tell you the answer I would have to draw a schematic of it for you all(its kind of complicated) ..but i dont know how to post an image..

how do you do that?

-regards

greg

[This message has been edited by mustangelectric (edited 03-17-2005).]

Hi,
If you cant figure out how to wire a 2 pole three wire dryer..

just use this schematic i made..
http://pg.photos.yahoo.com/ph/masterelectrician@sbcglobal.net/my_photos

it works everytime!

-regards

greg

[This message has been edited by mustangelectric (edited 03-18-2005).]

Nice one greg