4
1H/1C System
(1 transformer)
R
Power
[1]
Rc
[R+Rc joined by Slider Tab]
[2]
Y
Compressor contactor
C
24VAC common
[3]
W
Heat relay
G
Fan relay
Heat-only System
R
Power
[1]
Rc
[R+Rc joined by Slider Tab]
[2]
C
24VAC common
[3]
W
Heat relay
Heat-only System
(Series 20)
[5]
R
Series 20 valve terminal “R”
[1]
Rc
[R+Rc joined by Slider Tab]
[2]
Y
Series 20 valve terminal “W”
C
24VAC common
[3]
W
Series 20 valve terminal “B”
Heat-only System
(power open zone valve)
[5]
R
Power
[1]
Rc
[R+Rc joined by Slider Tab]
[2]
W
Valve
C
24VAC common
[3]
1H/1C System
(2 transformers)
R
Power (heating transformer)
[1]
Rc
Power (cooling transformer)
[1]
Y
Compressor contactor
C
24VAC common
[3, 4]
W
Heat relay
G
Fan relay
Heat-only System with Fan
R
Power
[1]
Rc
[R+Rc joined by Slider Tab]
[2]
C
24VAC common
[3]
W
Heat relay
G
Fan relay
Cool-only System
R
Power
[1]
Rc
[R+Rc joined by Slider Tab]
[2]
Y
Compressor contactor
C
24VAC common
[3]
G
Fan relay
2H/2C System
(1 transformer)
[6]
R
Power
[1]
Rc
[R+Rc joined by Slider Tab]
[2]
Y
Compressor contactor (stage 1)
C
24VAC common
[3]
W
Heat relay (stage 1)
G
Fan relay
W2
Heat relay (stage 2)
Y2
Compressor contactor (stage 2)
Wiring conventional systems: forced air and hydronics
Shaded areas below apply only to
TH6320U/TH6220U
or as otherwise noted.
NOTES
Wire specifications: Use 18- to 22-gauge thermostat wire. Shielded cable is not required.
[1]
Power supply. Provide disconnect means and overload
protection as required.
[2]
Move R-Slider Tab on UWP to the
R
setting. For more
information, see “Setting Slider Tabs” on page 3
[3]
Optional 24VAC common connection.
[4]
Common connection must come from cooling transformer.
[5]
In ISU set Heat system type to Radiant Heat. Set number of
cool stages to 0.
[6]
In Installer Setup, set system type to 2Heat/2Cool
Conventional.
