DIYbanter - View Single Post - 3-way switch

Doug Miller

In article . com, wrote:
On Jul 26, 6:55 pm, (Doug Miller) wrote:
In article . com,
wrote:
On Jul 26, 5:34 pm, Terry wrote:
The easiest way is to turn the power off and take loose both switches.
Only one wire of the 6 will be hot when you turn the power back on.
(This is the switch leg feed)

Turn the power back off, and tie this wire to the screw terminal of the
switch that is marked black. Connect the other two wires to the
remaining two screws.

Turn the power back on and check the 3 wires at the other switch box.
Two of these wires will be hot depending on the position of the other
switch. When you find these two, the wire that never energized when
you flipped the switch is the "return"

Turn the power back off and tie the "return" to the black colored screw
of the switch. Then connect the other two wires to the other two
terminals on the switch.

I like the 1st part, but I would assume the color of the hot wire that
was common on the 1st switch will be the same on the 2nd that feeds
the fixture.

Not necessarily a correct assumption. Terry's procedure is simple,
straightforward, and guaranteed to work as long as there's a ground available
in each box.

Guaranteed to work! By whom...?

I'll be happy to guarantee it. Correctly followed and applied, that procedure
will identify the correct wires every time, without fail.

Logic only works when you think the same.

Logic works all the time, and it works the same way every time. But it's just
like any other tool: if you don't know how to use it, you can't make it work,
but that doesn't mean the tool is broken. :-)

Some people get stuck with
words...or going a wrong way. I was offering a thought to maybe make
it simpler.

Trouble is, that's really only a little better than guessing. There simply
isn't any guarantee at all that the colors of the wires are the same at the
two switches. Or that the colors will be distinct -- ever seen a three-way
switch wired with two 14/2 cables instead of one 14/3? Which of the two black
wires (or the two white wires) is which?

Testing with a voltmeter, as Terry described, is quick, easy, and sure.

--
Regards,
Doug Miller (alphageek at milmac dot com)

It's time to throw all their damned tea in the harbor again.