Honeywell TH8320U Installation Instructions Manual page 6

TH8320U AND TH8321U TOUCH SCREEN PROGRAMMABLE THERMOSTATS
3 3
5
1
POWER SUPPLY. PROVIDE DISCONNECT MEANS AND OVERLOAD PROTECTION AS REQUIRED.
2
FACTORY INSTALLED JUMPER.
3 MUST CONNECT THE 24 VAC COMMON WHEN USING L. THE TERMINAL IS SHOWN AS EQUIPMENT MONITOR, CAN ALSO BE USED AS A 24 VAC
OUTPUT. SEE "L TERMINAL" SECTION FOR MORE INFORMATION.
4
"O/B" TERMINAL SET TO CONTROL AS EITHER "O" OR "B" IN THE INSTALLER SETUP.
5
OPTIONAL OUTDOOR OR INDOOR REMOTE SENSOR. AVAILABLE ON SELECT MODELS. WIRES MUST HAVE A CABLE SEPARATE FROM THE
THERMOSTAT CABLE.
Fig. 14. Typical hookup of multistage heat pump with no auxiliary/backup heat (2H/2C heat pump).
5 5
3
4
HEAT 2 RELAY
(AUXILIARY HEAT)
1
POWER SUPPLY. PROVIDE DISCONNECT MEANS AND OVERLOAD PROTECTION AS REQUIRED.
2
FACTORY INSTALLED JUMPER.
3 OUTDOOR SENSOR REQUIRED IN SYSTEM WITH FOSSIL FUEL BACKUP HEAT THAT IS NOT USING AN EXTERNAL FOSSIL FUEL KIT.
4
OPTIONAL OUTDOOR OR INDOOR REMOTE SENSOR. AVAILABLE ON SELECT MODELS. WIRES MUST HAVE A CABLE SEPARATE
FROM THE THERMOSTAT CABLE.
5
MUST CONNECT THE 24 VAC COMMON WHEN USING L. THE TERMINAL IS SHOWN AS EQUIPMENT MONITOR, CAN ALSO BE USED AS
A 24 VAC OUTPUT. SEE "L TERMINAL" SECTION FOR MORE INFORMATION.
6 "O/B" TERMINAL SET TO CONTROL AS EITHER "O" OR "B" IN THE INSTALLER SETUP.
Fig. 15. Typical hookup of single-stage heat pump with auxiliary/backup heat (2H/1C heat pump).
69-1706
HEAT PUMP
Y2
L
E
AUX
SI
S2
OUTDOOR/INDOOR
TEMPERATURE
SENSOR
COMPRESSOR 2
HEAT PUMP
Y2
L
E
AUX
SI
S2
OUTDOOR/INDOOR
TEMPERATURE
SENSOR
RC
2
R
O/B
Y
G
C
CHANGEOVER
VALVE
2
R
O/B
Y
G
C
CHANGEOVER
VALVE
EMERGENCY
HEAT RELAY
6
4 4
OPTIONAL 24 VAC
COMMON CONNECTION
FAN RELAY
COMPRESSOR 1
EQUIPMENT
MONITOR
6 6
OPTIONAL 24 VAC
COMMON CONNECTION
FAN RELAY
COMPRESSOR
RELAY
1
R
C
M19904
1
R
C
M19905