Thx9321 Thermostat Wiring Diagrams - Honeywell Home THX9321 Prestige 2.0 Manual

®
THX9321 PRESTIGE 2.0 AND THX9421 PRESTIGE

THX9321 Thermostat Wiring Diagrams

Typical wiring of a 3-heat / 2-cool heat pump system with
one transformer.
Transformer
120
VAC
VAC
O/B
CHANGEOVER VALVE
AUX/E
BACKUP HEAT
Y COMPRESSOR STAGE 1
Y2 COMPRESSOR STAGE 2
G FAN RELAY
L/A COMPRESSOR MONITOR
OR ZONE PANEL
K
6
Fig. 327. Prestige THX9321 and heat pump system with
one transformer.
Typical wiring of a 2-heat / 2-cool conventional system
with one transformer.
Transformer
120
VAC VAC
W HEAT STAGE 1
W2
HEAT STAGE 2
Y
COMPRESSOR STAGE 1
Y2
COMPRESSOR STAGE 2
G FAN RELAY
A
K
6
Fig. 328. Prestige THX9321 and 2-heat / 2-cool
conventional system with one transformer.
1 U1 and U2 terminals are dry contacts.
2 L/A terminal sends continuous output when thermostat is set to EM HEAT mode except when set up for Economizer or
TOD. See "Economizer Module Wiring Diagrams" beginning on page 150.
3 U1 or U2 terminals must be used for geothermal radiant heat (ISU 2010). Thermostat allows 2 stages of radiant heat—
geothermal (stage 1) and boiler (stage 2).
4 "U" terminals are normally open dry contacts when set up for geothermal radiant heat. You must install a field jumper if
radiant heat is powered by system transformer. Do NOT install a field jumper if radiant heat has its own transformer.
5 Remove jumper if using separate transformers.
6 Connect the THP9045 C-wire adapter to the K terminal in heating/cooling applications that do not have a common wire
at the thermostat. The K terminal cannot be used in heat-only applications. See THP9045 installation instructions for
more information.
NOTE: For setup and operation, see "Geothermal Radiant Heat" beginning on page 99.
68-0311—08
®
24
C
R
C
Rc
R
U1
U1
1
U2
2
U2
M32948A
24
C
R
C
Rc
R
5
U1
U1
1
U2
U2
M32949A
IAQ WITH EIM
Typical wiring of a 3-heat / 2-cool heat pump system with
two transformers.
Air Handler
Transformer
O/B
AUX/E
Y
Y2
G
L/A
K
6
Backup Heat
Transformer
Fig. 329. Prestige THX9321 and heat pump system with
Typical wiring for geothermal radiant heat, geothermal
forced-air and backup heat with one transformer. See
"Geothermal Radiant Heat" on page 99.
Transformer
O/B
AUX/E
Y
Y2
G
L/A
K
6
Fig. 330. Prestige THX9321 and geothermal radiant
heat, geothermal forced-air and backup heat with one
140
120 24
C
VAC VAC
R
CHANGEOVER VALVE
1 3
COMPRESSOR STAGE 1
COMPRESSOR STAGE 2
FAN RELAY
COMPRESSOR MONITOR
OR ZONE PANEL
2
BACKUP HEAT
120 24
R
VAC VAC
C
two transformers.
120 24
C
VAC VAC
R
CHANGEOVER VALVE
BACKUP HEAT
COMPRESSOR STAGE 1
4
COMPRESSOR STAGE 2
GEOTHERMAL
RADIANT
FAN RELAY
HEAT
STAGE 1
COMPRESSOR MONITOR
OR ZONE PANEL
2 3
transformer.
C
Rc
R
U1
U1
1
U2
U2
M32950A
C
Rc
R
U1
U1
U2
U2
M32951A