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TYPICAL WIRING
1F97-1277
Single
Stage
(SS)
Energized
in Cool
Mode
Energized
in Heat,
Off Mode
System
O
RH
+
B
CLASS II
TRANSFORMER
HOT
24VAC
NEUTRAL
120VAC
W
G
C*
-
Energized
on call
for Cool
(Com-
pressor)
Blower/
Circula-
tor Fan
Energiz-
ed on
call for
Heat or
Cool
(if ELE
is sel-
ected)
24 Volt
(Hot)
Cool
Power
remote
Temp-
erature
Sensor
Remote
Temp-
erature
Sensor
signal
Power
Remote
Temp-
erature
Sensor
Energized
on call for
Heat
Third wire
for 3-wire
zone valve
Y
RC
S
6
L
{
To Remote Temperature Sensor
24 Volt
(Hot)
Heat
24 Volt
Com-
mon
(option-
al)
CLASS II
TRANSFORMER
120VAC
HOT
24VAC
NEUTRAL
HEATING
COOLING
Diagnostic
Indicator
(See
Note
)
1
Jumper
Remove Jumper Wire
between RH & RC
Single
Stage
(SS)
Energiz-
ed in
Cool
Mode
Energized
in Heat
or Off
Mode
System
O
RH
+
B
CLASS II
TRANSFORMER
HOT
24VAC
NEUTRAL
120VAC
W
G
C*
-
Jumper
Energized
on call
for Cool
(Com-
pressor)
Blower/
Circula-
tor Fan
Energiz-
ed on
call for
Cool &
for Heat
(if ELE
is sel-
ected)
24 Volt
(Hot)
Cool
Power
Temp-
erature
Sensor
Remote
Temp-
erature
Sensor
Power
Remote
Temp-
erature
Sensor
Energized
on call for
Heat
Third
wire for
3-wire
zone
valve
Diagnostic
Indicator
(See
Note
)
Y
RC
S
6
L
{
To Remote Temperature Sensor
24 Volt
(Hot)
Heat
24 Volt
Com-
mon
(option-
al)
1
Single Stage System with Single Transformer
Single Stage with Two Transformers
* Common connection
required for fault or
malfunction indication
and remote sensor.
NOTE
: If continuous backlight or hardwired power input are de-
sired but do not function in both HEAT and COOL modes, cut
the heating transformer 24V wires and tape off. Connect the
neutral circuit disconnected from the heating transformer to the
neutral circuit of the cooling transformer. Disconnect the wire
to the RH terminal and install a jumper between RH and RC.
Depending on the system requirements, replace the cooling
transformer with a 75VA class II transformer if needed.
* Common connection
required for fault or
malfunction indication
and remote sensor.
NOTE
: Connection for Call for Service diagnostic indicator compatible with mechanical or electronic condenser control with Comfort Alert
TM
.
TYPICAL WIRING DIAGRAMS
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