Wiring - Honeywell T8775A Installation Instructions Manual

T8775A,C THE DIGITAL ROUND™ NON-PROGRAMMABLE THERMOSTATS

Wiring

IMPORTANT
Use 18-gauge wire to wire the T8775A,C
Thermostats.
All wiring must comply with local electrical codes
and ordinances. Disconnect the power supply to
prevent electrical shock or equipment damage.
Refer to Fig. 2 through 6 for typical wiring hookups.
R
1
1
POWER SUPPLY. PROVIDE DISCONNECT MEANS
AND OVERLOAD PROTECTION AS REQUIRED.
Fig. 2. Typical hookup of T8775A in a heat-only system.
Rc
2
R
1
VALVE COIL
1 POWER SUPPLY. PROVIDE DISCONNECT MEANS
AND OVERLOAD PROTECTION AS REQUIRED.
2 FACTORY INSTALLED JUMPER.
Fig. 3. Typical hookup of T8775C in heat-only system
69-1677ES
W
HEATING
RELAY OR
VALVE COIL
M19513
O
B
G
Y
W
HEATING
FAN
RELAY OR
RELAY
M19514
with fan.
2
R
1
1 POWER SUPPLY. PROVIDE DISCONNECT MEANS
AND OVERLOAD PROTECTION AS REQUIRED.
2 FACTORY INSTALLED JUMPER.
Fig. 4. Typical hookup of T8775C in heat-cool system
with single transformer.
Rc
2
R
RELAY OR
1
VALVE COIL
1 POWER SUPPLY. PROVIDE DISCONNECT MEANS
AND OVERLOAD PROTECTION AS REQUIRED.
REMOVE FACTORY INSTALLED JUMPER BETWEEN R AND R C .
2
Fig. 5. Typical hookup of T8775C in heat-cool system
with two transformers.
4
O
Rc
2
R
COMPRESSOR
CONTACTOR
1
1 POWER SUPPLY. PROVIDE DISCONNECT MEANS
AND OVERLOAD PROTECTION AS REQUIRED.
2 FACTORY INSTALLED JUMPER.
3 USE A JUMPER WIRE (NOT SUPPLIED) TO CONNECT W TO Y.
4 USE EITHER O OR B FOR HEAT PUMP CHANGEOVER.
Fig. 6. Typical hookup of T8775C in single-stage heat
2
O
B
Rc
G
Y
W
HEATING COMPRESSOR
RELAY OR CONTACTOR
VALVE COIL
B
G
Y
W
COMPRESSOR
CONTACTOR
HEATING
FAN
RELAY
B
G
Y
3
W
HEAT
CHANGEOVER
VALVE
FAN
CHANGEOVER
RELAY
pump system.
FAN
RELAY
M19515
1
M19517
COOL
VALVE
M19516