Service Instructions

ACCESSORIES WIRING DIAGRAMS
121
HIGH VOLTAGE!
DISCONNECT ALL POWER BEFORE SERVICING OR INSTALLING THIS
UNIT. MULTIPLE POWER SOURCES MAY BE PRESENT. FAILURE TO
DO SO MAY CAUSE PROPERTY DAMAGE, PERSONAL INJURY OR DEATH.
+5VDC
24VAC
G
POWER SUPPLY
INPUT
POWER SUPPLY COMMON
OUT TO HP CONTROL
P3-1
6.8K
P3-7
Y-HP
P1-6
P1-4
COMPRESSOR OUTPUT
P1-7
O
POWER SUPPLY OUT
TO THERMOSTAT
24VAC
Q2
K3
W1
POWER SUPPLY INPUT
(COMMON)
+VDC
E/W1
Y
P2-8
CALL FOR
REVERSING VALVE
P3-5
C
C
BLOWER FAN DEMAND
OUTPUT
P3-3
P1-8
Y-STAT
Y-FURN
C
P3-2
P1-1
P3-8
REVERSING VALVE
OUTPUT
BREAK FOR ODT
FURNACE DEMAND
OUTPUT
P1-3
R
24VAC
K4
HP CALL FOR FURNACE
(DURING DEFROST)
W2
Y2-STAT
Y2-FURN
CALL FOR
COMPRESSOR
P2-7
P3-6
+VDC
Y2
O
REVERSING
VALVE OUTPUT
Q1
Y
P2-4
K1
OT-NO
Y
P2-9
CALL FOR 2ND STAGE
COMPRESSOR
Y2
1.0K
G-FURN
P2-1
C
OT-C
C
SECOND STAGE
COMPRESSOR OUTPUT
G
CALL FOR
EMERGENCY HEAT
W1-FURN
W2-HP
F1
3A
OT-NC
24VAC
2ND STAGE COMPRESSOR
DEMAND OUTPUT
W1
CALL FOR
FURNACE HEAT
6.8K
G-STAT
+VDC
P3-4
F
U
R
N
A
C
E
P2-6
K2
ODT (OUTDOOR
THERMOSTAT)
Y
R
SECOND STAGE FURNACE
DEMAND OUTPUT
MICROPROCESSOR
Y2-HP
P1-5
CALL FOR 2ND STAGE
FURNACE HEAT
O
W2
CALL FOR
BLOWER FAN
T
H
E
R
M
O
S
T
A
T
P2-5
1 2
R
Y2
POWER
SUPPLY
COMPRESSOR
CONTACTOR OUTPUT
O
H
E
A
T
P
U
M
P
P2-3
+5VDC
W2
P3-9
P2-2
E
POWER SUPPLY COMMON
OUT TO THERMOSTAT
POWER SUPPLY OUT
TO HP CONTROL
C
P1-2
ALL FUEL SYSTEM AFE18-60A CONTROL BOARD
ALL FUEL CONTROL BOARD - AFE18-60A
This wiring diagram is for reference only. Not all wiring is as shown above.
Refer to the appropriate wiring diagram for the unit being serviced.
(For use with Heat Pumps in conjunction with 80% or 90% Single-Stage or Two-Stage Furnaces)