T8400C1099, T8401C1031 ELECTRONIC THERMOSTATS
3
69-1484-2
Fig. 4. Restrict wiring to shaded area
(T8400C1099 shown).
Fig. 5. Wiring connections
(T8400C1099 shown).
Fig. 6. Typical hookup of T8400C1099 in heat-cool
system with single transformer.
Fig. 7. Typical hookup of T8400C1099 in heat-cool
system with two transformers.
Fig. 8. Typical hookup of T8400C1099 in single-stage
heat pump systems.
KEEP WIRING IN
SHADED AREA
MOUNTING
SCREW HOLE
MOUNTING
SCREW HOLE
WIRING ENTRANCE
HOLE
M16432
G
Rc
R
Y
W
B
O
TERMINAL
SCREW
M13274
G
Rc
R
Y
W
B
O
FOR STRAIGHT INSERTION
STRIP 5/16 IN. (8 MM)
FOR WRAPAROUND
STRIP 7/16 IN. (11 MM)
L1
(HOT)
L2
1
1
COOLING
CONTACTOR
FAN
RELAY
HEATING
PRIMARY
CONTROL
24V
POWER SUPPLY. PROVIDE DISCONNECT MEANS AND
OVERLOAD PROTECTION AS REQUIRED.
FACTORY INSTALLED JUMPER.
M13275
Y
G
Rc
W
R
B
O
2
2
Y
G
Rc
W
2
4
R
B
O
M12562A
L1
(HOT)
L2
FAN
RELAY
HEAT
RELAY
L1
(HOT)
L2
COMPRESSOR
CONTACTOR
HEATING
TRANSFORMER
COOLING
TRANSFORMER
HEAT
DAMPER
COOL
DAMPER
1
POWER SUPPLY. PROVIDE DISCONNECT MEANS AND OVERLOAD
PROTECTION AS REQUIRED.
REMOVE RC TO R JUMPER WHEN INSTALLED ON A TWO TRANSFORMER
SYSTEM.
CAN BE USED FOR CHANGEOVER VALVE ON SINGLE-STAGE HEAT
PUMP SYSTEMS.
POWER TO R TERMINAL IS REQUIRED WHEN THE SYSTEM SWITCH IS IN
THE OFF POSITION.
2
3
3
1
1
3
4
L1
(HOT)
L2
1
COOL
CHANGEOVER
FAN
RELAY
COMPRESSOR
24V
M20880
HEAT
CHANGEOVER
TRANSFORMER
1
POWER SUPPLY. PROVIDE DISCONNECT MEANS
AND OVERLOAD PROTECTION AS REQUIRED.
CAN BE USED FOR CHANGEOVER VALVE ON
SINGLE-STAGE HEAT PUMP SYSTEMS.
FACTORY INSTALLED JUMPER.
FIELD INSTALLED JUMPER.
2
3
4
4
2
2
Y
G
Rc
W
R
B
O
3
