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RBM[_2_] RBM[_2_] is offline
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Default 3-way switch, always hot


"terry" wrote in message
...
On Jun 15, 2:39 pm, RLM wrote:
On Sun, 15 Jun 2008 10:14:36 -0400, John Smith wrote:
I just bought a 3-way switch. I notice that when hot wire is connected
to the black screw, both traveler wires are always hot no matter how I
flip the switch (the hot wire coming out of the other 3-way switch is
always hot, not responding to the position of this switch).


I measured the voltage across the black and either of the two traveler
screws and it was 0. However, if I measure the resistance, it does seem
to work (0 between the black and one of the traveler screws and infinite
if the switch is flipped. Same for both traveler screws.)


This doesn't make sense, does it?


You might want to bookmark these.

http://www.electrical-online.com/wiringdiagrams.htm

..
Agree use a lamp!
He's either picking up induced voltage from adjacent 'live' wires, or
capacitance coupling through switch? Cos even cheap meters are
sufficiently sensitive to do so; OR there is potential coming back on
the 'other' wire from the other 'switch' of the two switches used in
a so called '3 way switch' set up.
PS. Why do we call it '3 way'? Maybe cos of the usually three wires
between the two switches (compared to the usual two for a non-3 way
set up)?
OR ........ ?
Mostly it's a two switch arrangement; typically one switch at top and
another at bottom of stairs! Although there is a special 3rd switch
available (although never seen one) that swaps over the two carriers
of a double pole switch to allow use of witches in three locations.

You never use 3way witches in three locations. You must use at least one
warlock(4way) between the two witches