Wiring conventional and heat pump systems
Aux
Y
G
O
L
R
2H/1C Heat Pump System TH4210D
C
24 Vac common
B
Changeover valve energized in
heating
[5]
R
Power
[1]
L
Sends output when set to Em. Heat
O
Changeover valve energized in
cooling
[5]
G
Fan relay
Y
Compressor contactor
Aux
Auxiliary heat relay
E
Emergency heat relay
W
Y
G
O
Rc
R
B
1H/1C System TH4110D (1 transformer)
C
24 Vac common
R
[R+Rc joined by jumper]
Rc
Power
[1]
G
Fan relay
Y
Compressor contactor
W
Heat relay
W
Y
G
O
Rc
R
B
1H/1C System TH4110D (2 transformers)
C
24 Vac common
R
Power (heating transformer)
Rc
Power (cooling transformer)
G
Fan relay
Y
Compressor contactor
W
Heat relay
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]
Remove jumper for 2-transformer systems.
[3]
Optional 24 Vac common connection.
[4]
Common connection must come from cool-
ing transformer.
[5]
Use either O or B terminals for changeover
valve.
B
C
[3]
[8]
[9]
[9]
C
[3]
C
[3, 4]
[1, 2]
[1, 2]
W
Y
G
O
Rc
R
1H/1C Heat Pump System TH4110D
C
24 Vac common
B
Changeover valve energized in
heating
[5]
R
[R+Rc joined by jumper]
Rc
Power
[1]
O
Changeover valve energized in
cooling
[5]
G
Fan relay
Y
Compressor contactor
W
[W+Y joined by jumper]
W
O
Rc
R
Heat Only System TH4110D
C
24Vac common
R
[R+Rc joined by jumper]
Rc
Power
[1]
W
Heat relay
W
G
O
Rc
R
Heat Only System with Fan TH4110D
C
24 Vac common
R
[R+Rc joined by jumper]
Rc
Power
[1]
G
Fan relay
W
Heat relay
Y
G
O
Rc
R
Cool Only System TH4110D
C
24 Vac common
R
[R+Rc joined by jumper]
Rc
Power
[1]
G
Fan relay
Y
Compressor contactor
[6]
Use a small piece of wire (not supplied) to
connect W and Y terminals.
[7]
Set fan operation switch to Heat Pump
(see page 5) and configure system type
for heat pump (see page 6).
[8]
L terminal sends a continuous output when
thermostat is set to Em. Heat. Connect
to Honeywell zoning panels to switch the
panel to Emergency Heat.
[9]
Install field jumper between Aux and E if
there is no emergency heat relay.
3
B
C
[7]
[3]
[6]
B
C
[3]
B
C
[3]
B
C
[3]