Honeywell THX9321 Prestige 2.0 System Installation Manual page 13

Thermostat wiring guides — Prestige THX9321
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
COMPRESSOR MONITOR
L/A
OR ZONE PANEL
K
6
Typical wiring of a 3-heat / 2-cool heat
pump system with two transformers
(example - oil forced air backup heat)
Air Handler 120
Transformer
VAC VAC
O/B CHANGEOVER VALVE
AUX/E
Y COMPRESSOR STAGE 1
Y2
COMPRESSOR STAGE 2
G FAN RELAY
COMPRESSOR MONITOR
L/A
OR ZONE PANEL
2
K
6
Backup Heat
120
Transformer
VAC
VAC
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 wiring section.
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 Wiresaver Module 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.
24
C
R
C
Rc
R
U1
U1
1
U2
2
U2
MCR32948B
24
C
R
C
Rc
1 3
R
U1
U1
U2
U2
BACKUP HEAT
24
R
C
MCR32950A
THX9321/9421 Prestige
Typical wiring of a 2-heat / 2-cool con-
ventional system with one transformer
Transformer
W
W2
Y COMPRESSOR STAGE 1
Y2 COMPRESSOR STAGE 2
G
A
K
6
Typical wiring for geothermal radi-
ant heat, geothermal forced-air and
backup heat with one transformer. See
page 19 for operation.
Transformer
O/B
CHANGEOVER VALVE
AUX/E
Y
COMPRESSOR STAGE 1
Y2 COMPRESSOR STAGE 2
G
1
L/A COMPRESSOR MONITOR
K
6
13
IAQ and RF EIM
®
120
24
C
VAC
VAC
R
HEAT STAGE 1
HEAT STAGE 2
FAN RELAY
120
24
C
VAC
VAC
R
BACKUP HEAT
GEOTHERMAL
FAN RELAY RADIANT
HEAT
STAGE 1
OR ZONE PANEL
2
C
Rc
R
5
U1
U1
1
U2
U2
MCR32949A
C
Rc
R
4
U1
U1
U2
3
U2
MCR32951A
69-2490—05