6
7
WIRING TERMINAL
Wire specifications
18-24 gauge thermostat wire
Installation notes
• Ensure power at the HVAC
equipment is off .
• Loosen screw terminals,
insert stripped wire and
re-tighten .
• Push the excess wire
back into the opening and
plug the wall opening to
prevent drafts .
INSTALLATION
RC
– 24 VAC supply cooling*
R
– 24 VAC supply heating*
W
– First stage heat (conventional) / First stage auxiliary (heat pump)
Y
– First stage cooling (conventional) / First stage compressor (heat pump)
G
– Fan
C
– Common
S1 & S2
– Outdoor temperature sensor (optional)
O/B
– Reversing valve
L
– System fault indicator
W2
– Second stage heat (conventional) / Second stage auxiliary (heat pump)
Y2
– Second stage cooling (conventional) / Second stage compressor (heat pump)
* Jumper between RC & R is used in single transformer systems (see wiring diagrams).
C
G
Y
W
R
L
S1 S2 O/B
W2 Y2
RC
WIRING – SINGLE TRANSFORMER (USE
JUMPER WIRE) FOR HEAT/COOL SYSTEM
INSTALLATION
1st HEA
TING
1st COOLING
FA
N
2nd HEA
TING
2nd COOLING
OUTDOOR TEMP SENSOR
NOT USED
NOT USED
JUMPER
TRANSFORMER
C
G
Y
W
R
L
S1 S2 O/B
W2 Y2
RC
WIRING – TWO TRANSFORMERS (REMOVE
JUMPER WIRE) FOR HEAT/COOL SYSTEM
1st HEA
TIN
G
1st COOLING
FA
N
2nd HEA
TING
2nd COOLING
OUTDOOR TEMP SENSOR
NOT USED
NOT USED
HEA
TING
TRANSFORMER
COOLING
TRANSFORMER
C
G
Y
W
R
L
S1 S2 O/B
W2 Y2
RC
