Honeywell PRESTIGE THX9321 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 24
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
Air Handler 120 24
Transformer VAC
VAC
O/B
CHANGEOVER VALVE
AUX/E
Y
COMPRESSOR STAGE 1
Y2
COMPRESSOR STAGE 2
G
FAN RELAY
L/A COMPRESSOR MONITOR
OR ZONE PANEL
2
K
6
Backup Heat
120
24
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.
69-2490_B.indd 13
C
R
C
Rc
R
U1
U1
1
2
U2
MCR32948
C
R
C
Rc
1 3
R
U1
U1
1
U2
U2
BACKUP HEAT
R
C
MCR32950
THX9321/9421 Prestige
Typical wiring of a 2-heat / 2-cool con-
ventional system with one transformer
Transformer
120 24
VAC
VAC
W
HEAT STAGE 1
W2
HEAT STAGE 2
Y
COMPRESSOR STAGE 1
Y2
COMPRESSOR STAGE 2
G
FAN RELAY
A
K
6
Typical wiring for geothermal radiant
heat, geothermal forced-air and back-
up heat with one transformer
Transformer
120
24
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
13
IAQ and RF EIM
®
C
R
C
Rc
R
5
U1
U1
1
U2
U2
MCR32949
C
R
C
Rc
R
4
U1
GEOTHERMAL
RADIANT
U1
HEAT
STAGE 1
U2
3
2
U2
MCR32951
69-2490—03
7/13/2011 1:41:56 PM