3
WIRING CONNECTIONS
WIRING DIAGRAM
Refer to equipment manufacturers' instructions for specific
system wiring information . After wiring, see CONFIGURA-
TION section for proper thermostat configuration .
Wiring diagrams shown are for typical systems and describe
the thermostat terminal functions .
Terminal Designation
Description
B . . . . . . . . . . . . . . . . . . . Changeover valve for heat pump energized constantly in heating
O . . . . . . . . . . . . . . . . . . . Changeover valve for heat pump energized constantly in cooling and off
Y2 . . . . . . . . . . . . . . . . . . . 2nd Stage Compressor
Y . . . . . . . . . . . . . . . . . . . Compressor Relay
G . . . . . . . . . . . . . . . . . . . Fan Relay
RC . . . . . . . . . . . . . . . . . . . Power for Cooling
RH . . . . . . . . . . . . . . . . . . . Power for Heating
C . . . . . . . . . . . . . . . . . . . Common wire from secondary side of cooling (Optional) . Required for fault indication,
continuous backlight operation or remote temperature sensor operation
L . . . . . . . . . . . . . . . . . . . Malfunction indicator for systems with malfunction connection
6 . . . . . . . . . . . . . . . . . . . Powered closed 3rd wire for 3-wire zone valve
W/E . . . . . . . . . . . . . . . . . . Heat Relay/Emergency Heat Relay (Stage 1)
W2 . . . . . . . . . . . . . . . . . . . 2nd Stage Heat (3rd Stage Heat in HP2)
Blank . . . . . . . . . . . . . . . . . . Blank
- . . . . . . . . . . . . . . . . . . . . Common (DC) for wired remote temperature sensor
S . . . . . . . . . . . . . . . . . . . Frequency signal from remote temperature sensor
+ . . . . . . . . . . . . . . . . . . . Power (DC) to remote temperature sensor
TERMINAL DESIGNATION DESCRIPTIONS
Heat
Pump 1
(HP1)
Heat
Pump 2
(HP2)
Energiz-
ed in
Cool
& Off
Mode
Energiz-
ed in
Heat/
Emer-
gency
Mode
System
O
RH
+
B
CLASS II
TRANSFORMER
HOT
24VAC
NEUTRAL
120VAC
W/E
Jumper
G
C
-
W2
Jumper
No
Output 1st
Stage
Heat &
Cool
(Com-
pressor)
**
Blower/
Circula-
tor Fan
Energiz-
ed on
call for
Heat or
Cool
24 VAC
(Hot)
Cool
DC
supply
voltage
to re-
mote
Temp-
erature
Sensor
Remote
Temp-
erature
Sensor
signal
DC
Return
to
Remote
Temp-
erature
Sensor
Auxil-
iary &
Emer-
gency
Heat
1st
Stage
Power
Closed
Conn-
ection
for
3-wire
zone
valve
Fault
Indicator
or
System
Malfunc-
tion
Switch
Y2
Y
RC
S
6
L
{
To Remote Temperature Sensor
2nd
Stage
Heat/
Cool
(Com-
pressor)
24 VAC
(Hot)
Heat
24 VAC
Com-
mon
(option-
al) *
(Dual
Fuel
disabled)
Emer-
gency
heat
2nd stage
(Dual
Fuel
enabled)
Auxiliary
& Emer-
gency
heat
2nd stage
Comfort
Alert II module
or similar
malfunction
module
Heat Pump Connections
Refer to equipment manufacturers' instructions for specific system
wiring information .
You can configure the thermostat for use with the following heat pump
systems .
HEAT PUMP TYPE 1 (HP 1)
. Single stage compressor sys-
tem; gas or electric backup .
HEAT PUMP TYPE 2 (HP 2)
. Multi-stage compressor or two
compressor system with gas or electric backup .
After wiring, see INSTALLER CONFIGURATION section for proper
thermostat configuration .
NOTE: If your system does provide an E connection, jumper between
W2 and W/E should be removed .
* 24 VAC common connection optional for system operation .
Required for fault or malfunction indication, remote temperature
sensor, or for continuous backlight operation .
** Dual fuel option de-energizes compressor when auxiliary heat is
energized .
