Honeywell TH8321 Product Data page 85

Wiring with the THP9045 C-Wire Adapter
The THP9045 C-wire adapter is designed to be used with applicable thermostats in which a 24V common is required and
there are not enough wires. The K terminal on the thermostat can be used to operate both the fan and compressor on a
single wire, and the module is designed to receive the signal from the K terminal, split that signal and re-route it to operate
the compressor and/or fan for normal operation. See form 33-00342 for additional information.
C
K
Rc
R
U1
U1
U2
U2
Fig. 223. Example C-wire adapter wiring diagram for a conventional application.
C
K
Rc
R
U1
U1
U2
U2
Fig. 224. Example C-wire adapter wiring diagram for a heat pump application.
TH8321WF SUBBASE
CONVENTIONAL
S1 S1
S1 S1
W O/B
Y Y
G G
W2 AUX
-E
Y2 Y2
A LA
HEAT PUMP
TH8321WF SUBBASE
CONVENTIONAL
S1 S1
S1 S1
W
O/B
Y Y
G G
W2 AUX
-E
Y2 Y2
A LA
HEAT PUMP
1 MATCH THE WIRES FROM THE HEAT PUMP TO THE AIR HANDLER AS NORMAL.
ON SOME HEAT PUMPS, THE REVERSING VALVE IS LABELED B INSTEAD OF O.
2
VISIONPRO® 8000 SMART THERMOSTAT
FURNACE
R C R C
THERMOSTAT
AIR HANDLER
R C
Y2 AUX
THERMOSTAT
85
W Y G
C-WIRE
ADAPTOR
W C K R
M37962
1
2
O Y G
C-WIRE
ADAPTOR
W C K R
M37963
33-00096—04