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CT1001/CT1002 Touchscreen Programmable Thermostat
Table 2. Terminal Designation Descriptions.
Terminal Designation
Description
RC (see Note 1)
Power for cooling--connect to secondary side of cooling system
transformer
R (see Note 1)
Power for heating--connect to secondary side of heating system
transformer
C (see Note 2)
Common wire from secondary side of cooling system transformer
W
Heat relay
Y
Compressor contactor
G
Fan relay
Y2
Second stage cooling
W2
Second stage heat relay
O/B (see Note 3)
Changeover valve for heat pump systems
AUX
Auxiliary heat relay for heat pump systems
E
Emergency heat relay for heat pump systems
L (see note 4)
Equipment monitor for heat pump systems
S1, S2
Optional outdoor or indoor remote sensor
21
NOTES:
1. When used in a single-transformer system, leave metal jumper wire in place between RC and
R. If used on a two-transformer system, remove metal jumper wire between RC and R.
2. Common wire is optional when thermostat is used with batteries.
3. If thermostat is configured for a heat pump system in the Installer Setup, configure
changeover valve for cool (O-factory setting) or heat (B).
4. L terminal is an input (system monitor) when the System mode is in the HEAT, OFF, COOL or
AUTO position.
“L” terminal is a 24VAC output when System mode is Emergency Heat. When
using the
“L” terminal connect the 24VAC Common. See LCD indications on page 90.
.