Wiring
Shaded areas below apply only to TH8320/TH8321.
1H/1C Heat Pump (no auxiliary heat)
Rc
Power
[1]
R
[R+Rc joined by jumper]
O/B
Changeover valve
Y
Compressor relay
G
Fan relay
C
24VAC common
S1
Optional outdoor/remote sensor
S2
Optional outdoor/remote sensor
2H/1C Heat Pump (with auxiliary heat)
L
Equipment monitor
E
Emergency heat relay
Aux
Auxiliary heat relay (Heat 2)
Rc
Power
[1]
R
[R+Rc joined by jumper]
O/B
Changeover valve
Y
Compressor relay
G
Fan relay
C
24VAC common
S1
Optional outdoor/remote sensor
S2
Optional outdoor/remote sensor
See [notes] below
[1]
Power supply. Provide disconnect means and overload protection as required.
[3]
Optional 24VAC common connection.
[5]
O/B set to control as either O or B in installer setup.
[6]
If L terminal is used, 24VAC common (terminal C) must be connected.
[7]
Heat pump reset (powered continuously when thermostat is set to Em. Heat; system monitor
when set to Heat, Cool, or Off).
[8]
Install field jumper between Aux and E terminals if there is no emergency heat relay.
Wiring guide—heat pump systems
[5]
[3]
[6, 7]
[8]
[8]
[5]
[3]
2H/2C Heat Pump (no auxiliary heat)
Y2
Compressor 2 relay
Rc
Power
R
[R+Rc joined by jumper]
O/B
Changeover valve
Y
Compressor 1 relay
G
Fan relay
C
24VAC common
S1
Optional outdoor/remote sensor
S2
Optional outdoor/remote sensor
3H/2C Heat Pump (with auxiliary heat)
Y2
Compressor 2 relay
L
Equipment monitor
E
Emergency heat relay
Aux
Auxiliary heat relay (Heat 2)
Rc
Power
R
[R+Rc joined by jumper]
O/B
Changeover valve
Y
Compressor 1 relay
G
Fan relay
C
24VAC common
Optional outdoor/remote sensor
S1
S2
Optional outdoor/remote sensor
VisionPRO
TH8000 Series
TM
[1]
[5]
[3]
[6, 7]
[8]
[1]
[5]
[3]
[8]