66901 / 035-20393-001 Rev. C (1204)
6
Unitary Products Group
FIGURE 7:
Typical Variable Speed Air Handler Thermostat Wiring
FIGURE 8:
Typical Variable Speed Furnace Thermostat Wiring
VARIABLE
SPEED
AIR HANDLER
2 -STAGE
AIR CONDITIONER
C
Y1
R
W
O
G
C
Y1
R
O
Y
W2
W1
G
X/L
X/L
1
2
1
HUMIDISTAT CONTACTS OPEN ON HUMIDITY RISE.
JUMPER ON CFM SELECTION BOARD MUST BE
.
HUMIDISTAT
REMOVED
2
Y1, Y2, AND HUM LOCATED ON CFM SELECTION BOARD.
THERMOSTAT
E
Y2
Y2
HUM
BLU/YEL
YEL
BLK
RED
1
VARIABLE
SPEED
FURNACE
2-STAGE
AIR CONDITIONER
C
Y1
R
W
O
HUMIDISTAT CONTACTS OPEN ON HUMIDITY RISE.
JUMPER MUST BE IN
POSITION.
HUMIDISTAT INSTALLED?
YES
G
C
Y1
R
O
Y2/Y
W2
W1/W
G
HUM
X/L
X/L
1
2
THERMOSTAT
Y2
BLK
YEL
BLU/YEL
RED
2
HUM LOCATED ON CFM SELECTION BOARD.
E
FIGURE 9:
Typical Previous Generation Variable Speed Furnace
Thermostat Wiring
1
VARIABLE
SPEED
FURNACE
2-STAGE
AIR CONDITONER
C
Y1
R
W
O
HUMIDISTAT CONTACTS OPEN ON HUMIDITY RISE.
JUMPER ON CFM SELECTION BOARD MUST BE
.
HUMIDISTAT
REMOVED
G
C
Y1
R
O
Y
W2
W1
G
HUM
X/L
X/L
1
THERMOSTAT
Y2
BLK
YEL
BLU/YEL
RED
E
Y2
