3-WAY SWITCH
It is a lighting control that can turn “off” or turn
“on” a lighting fixture in two different
locations. It is called a 3-way switch because
there are 3 conductors connecting the
switches.
3-WAY SWITCH DIAGRAM
SPDT SWITCH BSPDT SWITCH A
Lighting Bulb
Conductor
Return Line
Live Side
3-WAY SWITCH OPERATION
•The operation of a 3-way switch is very simple:
When the two switches are in the same
position –both in position 1 or both in position 2
– the bulb is “off”.
When the two switches are in opposite or
unlike positions – switch A in position 1 and
switch B in position 2 ; or switch A in position 2
and switch B in position 1 – the bulb will turn
“on”.
SWITCH POSITIONS
Position 1 Position 2
Sw A in position 1; Sw B in position 1
Bulb is “Off”
SW A in position 2; Sw B in position 2
Bulb is “Off”
Sw A in position 1; Sw B in position 2
Bulb is “On”