"Dan" wrote in message
...
A rental property of mine has a stairway with a light controlled by a
switch
at the top & a switch at the bottom. Either switch will turn the light on
or off, independent of the other switch. A few weeks back, an assistant
of
mine removed one of the switches to do some drywall repair, unfortunately
not noting how the wires were attached. Each switch was 3 wires, the one
at
the bottom has a red, a white & a black wire. On this switch, the red
wire
goes to the common terminal (this switch was not disturbed & the setup did
work previously). The switch at the top has 2 black & one white wire. I
tried connecting the top switch so that the white wire is common, this way
I
can turn on the light with the top switch regardless of the bottom
switch's
position, and I can turn the light on & off with the bottom switch if the
light is left on at the top, but I cannot turn the light on with the
bottom
switch if the top on is off. So I'm wondering how I can determine the
connections for the top switch. There must be a way to do this with a
volt
meter. Suggestions?

TIA

Dan

White can be used as a switch leg or power in residential... Nice to know
huh.
It really depends on how the guy wired it. I would have used black and white
as travelers and black for the switch leg. Try looking into the box and see
which pair of wires are together. Chances are they are the travelers. The
wire alone will be the switch leg, or common, or on the dark screw.
Hope this helps.