Honeywell Home THX9321 Prestige 2.0 Manual page 135

Conventional System
Terminal
C Common wire from secondary side of cooling
transformer (if 2 transformers).
Rc* Cooling power
R* Heating power
W Heat Stage 1
W2 Heat Stage 2
Y Compressor Stage 1
Y2 Compressor Stage 2
G Fan Relay
A Connect to Economizer Module or Lighting Panel
(TOD).
U1 / U1 Relay for humidification, dehumidification,
U2 / U2 ventilation, or a stage of heating/cooling.
† Connect to K on C-wire adapter.
K
* Remove factory installed jumper for two transformer systems.
†
The THP9045A1098 C-wire adapter is used on heat/cool systems when you only have four wires at the thermostat and
you would like the thermostat to be powered with a common wire. Use the K terminal in place of the Y and G terminals on
conventional or heat pump systems to provide control of the fan and the compressor through a single wire—the unused
wire then becomes your common wire. See THP9045 instructions for more information.
CAUTION
Electrical Hazard.
Can cause electrical shock or equipment damage.
Disconnect power before wiring.
All wiring must comply with local electrical codes and
ordinances. See Fig. 324–332.
1. Select wiring diagram that corresponds with system
type and the equipment being installed (using the
Table 14. THX9321 Terminal Designation Descriptions.
Description
®
THX9321 PRESTIGE 2.0 AND THX9421 PRESTIGE
Terminal
C Common wire from secondary side of cooling
transformer.
Rc* Cooling power
R Heating power
O/B Changeover valve for heat pumps
AUX-E Backup Heat/Emergency Heat
Y Compressor Stage 1
Y2 Compressor Stage 2
G Fan Relay
L/A Connect to Compressor Monitor, Zone Panel,
Economizer Module or Lighting Panel (TOD).
U1/ U1 Relay for humidification, dehumidification,
U2 / U2 ventilation, or a stage of heating/cooling.
† Connect to K on C-wire adapter.
K
EIM or wiring the thermostat directly to the HVAC
equipment).
2. Loosen the screws for the appropriate terminals.
Insert wires in the terminal block under the loosened
screw. See Fig. 322.
3. Securely tighten each screw.
4. Push excess wire back into the hole.
5. Plug the hole with nonflammable insulation to pre-
vent drafts from affecting the thermostat.
6. See Fig. 324–332 for typical wiring hookups.
135
®
IAQ WITH EIM
Heat Pump
Description
68-0311—08