TH8320U AND TH8321U TOUCH SCREEN PROGRAMMABLE THERMOSTATS
69-1706
4
Fig. 9. Typical hookup of heat only Series 20 system.
Fig. 10. Typical hookup of cool only system
(1C conventional).
Fig. 11. Typical hookup of conventional multistage two-stage heating and two-stage cooling
in a single transformer system (2H/2C or 2H/1C or 1H/2C conventional).
M19899
OUTDOOR/INDOOR
TEMPERATURE
SENSOR
POWER SUPPLY. PROVIDE DISCONNECT MEANS AND OVERLOAD
PROTECTION AS REQUIRED.
FACTORY INSTALLED JUMPER.
OPTIONAL OUTDOOR OR INDOOR REMOTE SENSOR. AVAILABLE
ON SELECT MODELS. WIRES MUST HAVE A CABLE SEPARATE
FROM THE THERMOSTAT CABLE.
1
3
2
3
Y2
RC
S1
R
S2
W
W2
Y
G
C
2
CONVENTIONAL
R
TR
C
1
TR
W
B
R
SERIES 20
MOTOR OR
VALVE
M19900
OUTDOOR/INDOOR
TEMPERATURE
SENSOR
FAN
RELAY
R
C
POWER SUPPLY. PROVIDE DISCONNECT MEANS AND OVERLOAD
PROTECTION AS REQUIRED.
FACTORY INSTALLED JUMPER.
OPTIONAL OUTDOOR OR INDOOR REMOTE SENSOR. AVAILABLE
ON SELECT MODELS. WIRES MUST HAVE A CABLE SEPARATE
FROM THE THERMOSTAT CABLE.
1
1
3
2
3
OPTIONAL
24 VAC
COMMON
CONNECTION
Y2
RC
S1
R
S2
W
W2
Y
G
C
2
CONVENTIONAL
COMPRESSOR
CONTACTOR
RC
R
W
Y
G
C
Y2
W2
S2
S1
CONVENTIONAL
COOL RELAY 2
COOL RELAY 1
M19901
HEAT RELAY 1
FAN RELAY
HEAT RELAY 2
R
C
POWER SUPPLY. PROVIDE DISCONNECT MEANS AND OVERLOAD PROTECTION AS REQUIRED.
1
1
2
2
3
FACTORY INSTALLED JUMPER.
OPTIONAL OUTDOOR OR INDOOR REMOTE SENSOR. AVAILABLE ON SELECT MODELS. WIRES MUST
HAVE A CABLE SEPARATE FROM THE THERMOSTAT CABLE.
OPTIONAL 24 VAC
COMMON CONNECTION
MUST COME FROM
THE COOLING
TRANSFORMER.
OUTDOOR/INDOOR
TEMPERATURE
SENSOR