Cdt900 series touchscreen programmable thermostata – Comfort Stat CDT901 User Manual
Page 34

CDT900 Series Touchscreen Programmable Thermostata
1. POWER SUPPLY. PROVIDE DISCONNECT MEANS AND OVERLOAD PROTECTION AS REQUIRED
2. FACTORY INSTALLED JUMPER.
3
.
OUTDOOR SENSOR REQUIRED IN SYSTEM WITH FOSSIL FUEL BACKUP HEAT THAT IS NOT USING AN EXTERNAL FOSSIL FUEL KIT
4
.
OPTIONAL OUTDOOR OR INDOOR REMOTE SENSOR. AVAILABLE ON SELECT MODELS. WIRES MUST HAVE A CABLE SEPARATE FROM THE
THERMOSTAT CABLE
5
.
MUST CONNECT THE 24 VAC COMMON WHEN USING L. THE TERMINAL IS SHOWN AS EQUIPMENT MONITOR, CAN ALSO BE USED AS
A 24 VAC OUTPUT. SEE "HEAT PUMP LED" SECTION FOR MORE INFORMATION.
6
."O/B" TERMINAL SET TO CONTROL AS EITHER "O" OR "B" IN THE INSTALLER SETUP.
Fig. 20. Typical hookup of single-stage heat pump with auxiliary/backu
heat (2H/1C heat pump).
33
3
4
HEAT PUMP
S1 S2 C R RC W W2 Y2 Y G
S1 S2 C R RC E L Y2 Y G
O/B AUX
OUTDOOR/INDOOR
TEMPERATURE
SENSOR
2
R
C 1
CHANGEOVER
VALVE
FAN RELAY
OPTIONAL
24VAC
COMMON
CONNECTION
6
5
COMPRESSOR
RELAY
EMERGENCY
HEAT RELAY
HEAT 2 RELAY
(AUXILIARY HEAT)
EQUIPMENT
MONITOR