Installation Guide
Wiring
1H/1C System (1 transformer)
R
Power
[1, 6]
W
Heat relay
Y
Compressor contactor
G
Fan relay
C
24VAC common
S1/S2 Optional outdoor/remote/discharge
sensor
U1/U1 Optional IAQ relay
Heat Only System
R
Power
[1]
W
Heat relay
C
24VAC common
S1/S2 Optional outdoor/remote/discharge
sensor
U1/U1 Optional IAQ relay
Heat Only System (Series 20)
R
Series 20 valve terminal "R"
W
Series 20 valve terminal "B"
Y
Series 20 valve terminal "W"
C
24VAC common
S1/S2 Optional outdoor/remote/discharge
sensor
U1/U1 Optional IAQ relay
See [notes] below
[1]
Power supply. Provide disconnect means and overload protection as required.
[2]
Optional 24VAC common connection.
[6]
Only works with single transformer systems.
69-2389—03
Wiring guide—conventional systems
[2]
[2]
[1]
[2]
2H/2C System (1 transformer)
Y2
Cool relay 2
W2
Heat relay 2
R
Power
[1, 6]
W
Heat relay 1
Y
Cool relay 1
G
Fan relay
C
24VAC common
S1/S2 Optional outdoor/remote/discharge
sensor
U1/U1 Optional IAQ relay
Heat Only System With Fan
R
Power
[1, 6]
W
Heat relay
G
Fan relay
C
24VAC common
S1/S2 Optional outdoor/remote/discharge
sensor
U1/U1 Optional IAQ relay
Cool Only System
R
Power
[1]
Y
Compressor contactor
G
Fan relay
C
24VAC common
S1/S2 Optional outdoor/remote/discharge
sensor
U1/U1 Optional IAQ relay
4
[2]
[2]
[2]