Honeywell TH8320U, TH8321U User Manual
TH8320U and TH8321U Touch Screen
Programmable Thermostats
INSTALLATION INSTRUCTIONS
APPLICATION
The TH8320U and TH8321U Touch Screen Universal Programmable Thermostats provide electronic control of 24 Vac
heating and cooling systems or 750 mV heating system. See Table 1 for a general description.
Table 1. TH832 Thermostats Description.
Model
TH8320U Batteries or
TH8321U System and Fan selection
MERCURY NOTICE
If this control is replacing a control that contains
mercury in a sealed tube, do not place your old
control in the trash. Dispose of properly.
Contact your local waste management authority
for instructions regarding recycling and the
proper disposal of the old control.
Power
Method Changeover System Selection Fan Selection Comments
common wire
Automatic or
manual
selectable
Heat-Off-CoolAuto (Em. Heat for
heat pumps)
On-Auto-Circ System and Fan selection
vary based on system type
vary based on System type.
Humidity sensor to control
dehumidification.
Selecting Location
Install the thermostat about 5 ft. (1.5m) above the floor in
an area with good air circulation at average temperature.
See Fig. 1.
INSTALLATION
When Installing this Product...
1. Read these instructions carefully. Failure to follow
the instructions can damage the product or cause
a hazardous condition.
2. Check the ratings given in the instructions to make
sure the product is suitable for your application.
3. Installer must be a trained, experienced service
technician.
4. After completing installation, use these instructions
to check out the product operation.
® U.S. Registered Trademark
Copyright © 2004 Honeywell International Inc. • • All Rights Reserved
NO
NO
YES
NO
5 FEET
[1.5 METERS]
Fig. 1. Selecting thermostat location.
M19925
69-1706
TH8320U AND TH8321U TOUCH SCREEN PROGRAMMABLE THERMOSTATS
CO
L
SC
S
H
UMP
S1
2
C
G
C
Do not install the thermostat where it can be affected by:
— Drafts or dead spots behind doors and in corners.
— Hot or cold air from ducts.
— Radiant heat from sun or appliances.
— Concealed pipes and chimneys.
— Unheated (uncooled) areas such as an outside wall
behind the thermostat.
Installing Wallplate
CAUTION
Electrical Hazard.
Can cause electrical shock or equipment
damage.
Disconnect power before wiring.
The thermostat can be mounted horizontally on the wall
or on a 4 in. x 2 in. (101.6 mm x 50.8 mm) wiring box.
1. Position and level the wallplate (for appearance
only).
2. Use a pencil to mark the mounting holes.
WALL
WIRES THROUGH WALL
AND WIRE SLOT
WALL ANCHORS (2)
MOUNTING
HOLES (2)
MOUNTING
SCREWS (2)
Fig. 2. Mounting wallplate.
3. Remove the wallplate from the wall and, if drywall,
drill two 3/16-in. holes in the wall, as marked. For
firmer material such as plaster, drill two 7/32-in.
holes. Gently tap anchors (provided) into the drilled
holes until flush with the wall.
4. Position the wallplate over the holes, pulling wires
through the wiring opening. See Fig. 2.
5. Insert the mounting screws into the holes and
tighten.
M19916
3. Securely tighten each screw.
4. Push excess wire back into the hole.
5. Plug the hole with nonflammable insulation to
prevent drafts from affecting the thermostat.
EAT P
NVENTIONA
Y2
L
E
AUX
S1
S2
Fig. 3. Selecting terminal identifications for
Table 2. Selecting Terminal Identifications for
W2
S
system type.
System Type.
System Type
R
W
Y
REW TERMINAL
Wallplate
Terminal
Identifications
RC
R
O/B
Y
G
C
M19951
Wiring
Diagram
Reference
Standard Heat/Cool Conventional 5, 6
Heat Only Conventional 7
Heat Only with Fan Conventional 8
Heat Only Series 20 Conventional 9
Cool Only Conventional 10
Standard Multistage
up to 2 Heat/2 Cool
Heat Pump with No
Auxiliary Heat
Heat Pump with
Auxiliary Heat
Conventional 11, 12
Heat Pump 13, 14
Heat Pump 15, 16
WIRING (FIG. 5-16)
All wiring must comply with local electrical codes and
ordinances.
1. Select set of terminal identifications (Table 2) that
corresponds with system type (conventional or
heat pump in Fig. 3).
2. Loosen the screws for the appropriate system type
selected; see Table 2. Insert wires in the terminal
block under the loosened screw. See Fig. 4.
69-1706 2
Fig. 4. Inserting wires in terminal block.
IMPORTANT
Use 18 gauge thermostat wire.
M19917
TH8320U AND TH8321U TOUCH SCREEN PROGRAMMABLE THERMOSTATS
CONVENTIONAL
RC
Y2
W2
S1
S2
3
OUTDOOR/INDOOR
TEMPERATURE
SENSOR
1
POWER SUPPLY. PROVIDE DISCONNECT MEANS AND OVERLOAD
PROTECTION AS REQUIRED.
2
FACTORY INSTALLED JUMPER.
3
OPTIONAL OUTDOOR OR INDOOR REMOTE SENSOR. AVAILABLE
ON SELECT MODELS. WIRES MUST HAVE A CABLE SEPARATE
FROM THE THERMOSTAT CABLE.
Fig. 5. Typical hookup of conventional single-stage
heat and cool system with single transformer
Y2
W2
S1
S2
3
OUTDOOR/INDOOR
TEMPERATURE
SENSOR
1
POWER SUPPLY. PROVIDE DISCONNECT MEANS AND OVERLOAD
PROTECTION AS REQUIRED.
2
REMOVE FACTORY INSTALLED JUMPER.
3
OPTIONAL OUTDOOR OR INDOOR REMOTE SENSOR. AVAILABLE
ON SELECT MODELS. WIRES MUST HAVE A CABLE SEPARATE
FROM THE THERMOSTAT CABLE.
2
R
W
Y
G
C
CONNECTION
FAN
RELAY
COMPRESSOR
CONTACTOR
HEAT RELAY
(1H/1C conventional).
CONVENTIONAL
RC
2
R
W
Y
G
C
CONNECTION
FAN
RELAY
COMPRESSOR
CONTACTOR
HEAT RELAY
OPTIONAL
24 VAC
COMMON
OPTIONAL
24 VAC
COMMON
M19895
M19896
CONVENTIONAL
RC
1
R
C
Y2
W2
S1
S2
3
OUTDOOR/INDOOR
TEMPERATURE
SENSOR
1
POWER SUPPLY. PROVIDE DISCONNECT MEANS AND OVERLOAD
PROTECTION AS REQUIRED.
2
FACTORY INSTALLED JUMPER.
3
OPTIONAL OUTDOOR OR INDOOR REMOTE SENSOR. AVAILABLE
ON SELECT MODELS. WIRES MUST HAVE A CABLE SEPARATE
FROM THE THERMOSTAT CABLE.
Fig. 7. Typical hookup of heat-only system
Y2
W2
1
R
C
1
C
R
OUTDOOR/INDOOR
1
2
3
S1
S2
3
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.
Fig. 8. Typical hookup of heat only system with fan
2
R
W
Y
G
C
HEAT RELAY
(1H conventional).
CONVENTIONAL
RC
2
R
W
Y
G
C
FAN
RELAY
HEAT RELAY
(1H conventional).
CONNECTION
OPTIONAL
24 VAC
COMMON
OPTIONAL
24 VAC
COMMON
CONNECTION
1
R
C
M19897
1
R
C
M19898
Fig. 6. Typical hookup of conventional single-stage
heat and cool system with two transformers
(1H/1C conventional).
3 69-1706
TH8320U AND TH8321U TOUCH SCREEN PROGRAMMABLE THERMOSTATS
C
G
CS2S1
CO
L
CONVENTIONAL
RC
Y2
W2
S1
S2
3
OUTDOOR/INDOOR
TEMPERATURE
SENSOR
1
POWER SUPPLY. PROVIDE DISCONNECT MEANS AND OVERLOAD
PROTECTION AS REQUIRED.
2
FACTORY INSTALLED JUMPER.
3
OPTIONAL OUTDOOR OR INDOOR REMOTE SENSOR. AVAILABLE
ON SELECT MODELS. WIRES MUST HAVE A CABLE SEPARATE
FROM THE THERMOSTAT CABLE.
2
R
W
Y
G
C
W BR
SERIES 20
MOTOR OR
TR
TR
1
VALVE
M19899
Fig. 9. Typical hookup of heat only Series 20 system.
NVENTIONA
R
OUTDOOR/INDOOR
TEMPERATURE
SENSOR
HEAT RELAY 2
1
POWER SUPPLY. PROVIDE DISCONNECT MEANS AND OVERLOAD PROTECTION AS REQUIRED.
2
FACTORY INSTALLED JUMPER.
3
OPTIONAL OUTDOOR OR INDOOR REMOTE SENSOR. AVAILABLE ON SELECT MODELS. WIRES MUST
HAVE A CABLE SEPARATE FROM THE THERMOSTAT CABLE.
COOL RELAY 2 COOL RELAY 1
HEAT RELAY 1
R
C
CONVENTIONAL
RC
Y2
W2
S1
S2
3
OUTDOOR/INDOOR
TEMPERATURE
SENSOR
1
POWER SUPPLY. PROVIDE DISCONNECT MEANS AND OVERLOAD
PROTECTION AS REQUIRED.
2
FACTORY INSTALLED JUMPER.
3
OPTIONAL OUTDOOR OR INDOOR REMOTE SENSOR. AVAILABLE
ON SELECT MODELS. WIRES MUST HAVE A CABLE SEPARATE
FROM THE THERMOSTAT CABLE.
Fig. 10. Typical hookup of cool only system
COMMON CONNECTION
MUST COME FROM
2
R
W
Y
G
C
RELAY
COMPRESSOR
CONTACTOR
(1C conventional).
OPTIONAL 24 VAC
THE COOLING
TRANSFORMER.
FAN
OPTIONAL
24 VAC
COMMON
CONNECTION
FAN RELAY
M19901
1
R
C
M19900
1
R
C
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).
69-1706 4
TH8320U AND TH8321U TOUCH SCREEN PROGRAMMABLE THERMOSTATS
C
G
CS2S1
CO
L
C
O/
G
C
UX
SI
S2
P
3
COMMON CO
ON
NVENTIONA
R
OPTIONAL 24 VAC
COMMON CONNECTION
MUST COME FROM
THE COOLING
TRANSFORMER.
OUTDOOR/INDOOR
3
TEMPERATURE
SENSOR
HEAT RELAY 2
1
POWER SUPPLY. PROVIDE DISCONNECT MEANS AND OVERLOAD PROTECTION AS REQUIRED.
2
FACTORY INSTALLED JUMPER REMOVED.
OPTIONAL OUTDOOR OR INDOOR REMOTE SENSOR. AVAILABLE ON SELECT MODELS. WIRES MUST HAVE A CABL
3
SEPARATE FROM THE THERMOSTAT CABLE.
Fig. 12. Typical hookup of conventional multistage two-stage heating and two-stage cooling
in a two-transformer system (2H/2C or 2H/1C or 1H/2C conventional).
COOL RELAY 2 COOL RELAY 1
HEAT RELAY 1
FAN RELAY
HEAT PUM
R
1
R
C
M19902
1
R
C
1
R
C
B
A
OPTIONAL 24 VAC
NNECTI
OUTDOOR/INDOOR
4
TEMPERATURE
SENSOR
POWER SUPPLY. PROVIDE DISCONNECT MEANS AND OVERLOAD PROTECTION AS REQUIRED.
1
FACTORY INSTALLED JUMPER.
2
"O/B" TERMINAL SET TO CONTROL AS EITHER "O" OR "B" IN THE INSTALLER SETUP.
3
OPTIONAL OUTDOOR OR INDOOR REMOTE SENSOR. AVAILABLE ON SELECT MODELS. WIRES MUST HAVE A CABLE SEPARATE
4
FROM THE THERMOSTAT CABLE.
CHANGEOVER
VALV E
Fig. 13. Typical hookup of single-stage heat pump with no auxiliary/backup heat (1H/1C heat pump).
5 69-1706
FAN RELAY
COMPRESSOR
M19903
TH8320U AND TH8321U TOUCH SCREEN PROGRAMMABLE THERMOSTATS
C
O/
G
C
UX
SI
S2
P
3
COMMON CO
ON
O/
G
C
UX
SI
S2
P
6
5
COMMON CO
ON
HEAT PUM
R
B
A
OPTIONAL 24 VAC
NNECTI
OUTDOOR/INDOOR
TEMPERATURE
5
SENSOR
POWER SUPPLY. PROVIDE DISCONNECT MEANS AND OVERLOAD PROTECTION AS REQUIRED.
1
FACTORY INSTALLED JUMPER.
2
MUST CONNECT THE 24 VAC COMMON WHEN USING L. THE TERMINAL IS SHOWN AS EQUIPMENT MONITOR, CAN ALSO BE USED AS A 24 VAC
3
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.
CHANGEOVER
VALV E
Fig. 14. Typical hookup of multistage heat pump with no auxiliary/backup heat (2H/2C heat pump).
HEAT PUM
FAN RELAY
COMPRESSOR 1COMPRESSOR 2
EQUIPMENT
MONITOR
M19904
1
R
C
1
R
C
A
3
OUTDOOR/INDOOR
TEMPERATURE
4
SENSOR
HEAT 2 RELAY
(AUXILIARY HEAT)
POWER SUPPLY. PROVIDE DISCONNECT MEANS AND OVERLOAD PROTECTION AS REQUIRED.
1
FACTORY INSTALLED JUMPER.
2
OUTDOOR SENSOR REQUIRED IN SYSTEM WITH FOSSIL FUEL BACKUP HEAT THAT IS NOT USING AN EXTERNAL FOSSIL FUEL KIT.
3
OPTIONAL OUTDOOR OR INDOOR REMOTE SENSOR. AVAILABLE ON SELECT MODELS. WIRES MUST HAVE A CABLE SEPARATE
4
FROM THE THERMOSTAT CABLE.
MUST CONNECT THE 24 VAC COMMON WHEN USING L. THE TERMINAL IS SHOWN AS EQUIPMENT MONITOR, CAN ALSO BE USED AS
5
A 24 VAC OUTPUT. SEE "L TERMINAL" SECTION FOR MORE INFORMATION.
"O/B" TERMINAL SET TO CONTROL AS EITHER "O" OR "B" IN THE INSTALLER SETUP.
6
Fig. 15. Typical hookup of single-stage heat pump with auxiliary/backup heat (2H/1C heat pump).
69-1706 6
EMERGENCY
HEAT RELAY
B
CHANGEOVER
VALV E
OPTIONAL 24 VAC
NNECTI
FAN RELAY
COMPRESSOR
RELAY
M19905
Loading...