Fig.
11—Unit
Wiring
Diagram
A92176
FU1
IDR
PL1-3
PR-1
PR-2
SEC-1
SEC-2
TRAN
24VAC
115VAC
BLWM
LO
MED LO
MED HI
HI
COM
CAP
L2
COM
4
3
2
1
C
CFR
HFR
PL4
NOTE#4
NOTE#8
EAC-1
EAC-2
L1
ILK
EQUIPMENT GROUND
TO 115V AC FIELD DISCONNECTIONS
NOTE #5
NOTE#10
PL2
L1
L2
PL1-1
IDR
PL1-4
ALS
FL
LS
PL1-7
R
Y
W
G
C
NOTE #1
CFR
NOTE #10
PL1-2
PL1-6
NC
NO
PRS
C
DSS
TH
TR
PILOT
MGV
GV
PL1-8
TIME
DELAY
LOGIC
HFR
3A
FUSE
PL1-9
(WHEN USED)
NOTE #7
SCHEMATIC
DIAGRAM
MGV
1
4
7
2
5
8
3
6
9
BLWM
MED LO
MED HI
HI
COM
LO
CAP
PRS
C
NO
NC
DSS
BRN
TH
PILOT
GV
TR
ALS
(WHEN USED)
NOTE #7
FL
LS
ORN
YEL
BRN
BLU
RED
BLK
RED
BLU
BLK
BLK
BLU
RED
WHT
TRAN
WHT
ILK
NOTE #5
WHT
BLK
IDM
GRN
JB
GRN
BLK
WHT
FU2
FUSED DISCONNECT
SWITCH (WHEN REQ'D)
BRN
BRN
WHT
BLK
RED
WHT
BLK
COM
PR2
L2
L1
PR1
HFR
CFR
LO
HI
NOTE #10
EAC-1
EAC-2
W
Y
R
C
G
NOTE #9
PCB
NOTE #1
GROUND
SCREW
REQ'D
FU1
3AMP
FUSE
NOTE #8
SEC-1
SEC-2
IDR
PL1
CONNECTION
DIAGRAM
JUNCTION
TERMINAL
PCB TERMINAL
FACTORY POWER WIRING (120VAC)
FACTORY CONTROL WIRING (120VAC)
FIELD POWER WIRING (120VAC)
CONDUCTOR ON PCB
FIELD WIRING SCREW TERMINAL
FIELD GROUND
EQUIPMENT GROUND
FIELD SPLICE
PLUG RECEPTACLE
AUX. LIMIT SWITCH (OVER TEMP), SPST-(N.C.),
MANUAL RESET
BLOWER MOTOR
CAPACITOR
COOLING FAN RELAY, SPDT
DRAFT SAFEGUARD SWITCH, SPST-(N.C.), MANUAL RESET
ELECTRONIC AIR CLEANER CONNECTION (115VAC)
ELECTRONIC AIR CLEANER CONNECTION (COMMON)
FUSE, 3 AMP, AUTOMOTIVE BLADE TYPE
FUSE, FIELD INSTALLED
FUSIBLE LINK
GAS VALVE, (REDUNDANT)
HEATING FAN RELAY, SPST (N.O.)
INDUCED DRAFT MOTOR
INDUCER DRAFT RELAY, DPST-(N.O.)
BLOWER DOOR INTERLOCK SWITCH, SPST-(N.O.)
JUNCTION BOX
LIMIT SWITCH (OVER TEMP), SPST-(N.C.), AUTO RESET
PRINTED CIRCUIT BOARD (FURNACE CONTROL)
9-CIRCUIT CONNECTOR (PCB1)
2-CIRCUIT CONNECTOR (L1, L2)
5-CIRCUIT PLUG CONNECTOR (BLWM)
PRESSURE SWITCH, SPDT
TRANSFORMER (115VAC/24VAC)
ALS
BLWM
CAP
CFR
DSS
EAC-1
EAC-2
FU1
FU2
FL
GV
HFR
IDM
IDR
ILK
JB
LS
PCB
PL1
PL2
PL4
PRS
TRAN
LEGEND
NOTES:
1. INTERNALLY CONNECTED TO EQUIPMENT GROUND THROUGH MOUNTING SCREW.
2. IF ANY OF THE ORIGINAL EQUIPMENT WIRE IS REPLACED, USE WIRE RATED FOR
105° C.
3. BLOWER MOTOR (BLWM) & INDUCER MOTOR (IDM) CONTAIN AUTO-RESET
THERMAL OVERLOAD SWITCH.
4. BLOWER MOTOR FACTORY SPEED SELECTIONS (PL4) ARE FOR AVERAGE
CONDITIONS. SEE INSTALLATION INSTRUCTIONS FOR DETAILS ON OPTIMUM
SPEED SELECTIONS.
5. USE ONLY COPPER WIRE BETWEEN THE DISCONNECT SWITCH AND THE
FURNACE JUNCTION BOX (JB).
6. SYMBOLS ARE ELECTRICAL REPRESENTATIONS ONLY.
7. AUXILIARY LIMIT SWITCH (ALS) USED ON DOWNFLOW MODELS ONLY.
8. THE TRANSFORMER 24VAC WINDING IS PROTECTED BY A 3 AMP AUTOMOTIVE
BLADE TYPE FUSE ON THE CONTROL BOARD. A 24VAC SHORT TO GROUND
DURING INSTALLATION, CHECKOUT, OPERATION, SERVICE OR MAINTENANCE
COULD CAUSE THIS FUSE TO OPEN. DO NOT REPLACE THE 3 AMP FUSE
WITH ANY OTHER SIZE FUSE.
9. BLOWER MOTOR (BLWM) ADJUSTABLE OFF-DELAY. FACTORY SET: 120 SECS.
CUT RESISTOR: 180 SECS.
10. WHEN CFR RELAY IS ENERGIZED, HFR RELAY IS ALSO ENERGIZED.
319593-401 REV. C
RED
WHT
4
3
2
1
C
PL2
1
2
NOTE #4
PL4
IDM
IDR
—9—
