8T8624C,D
INSTALLATION
DENOTES THERMOSTAT TO SUBBASE INTERCONNECTION. M3765
HEATING
TRANSFORMER
R
C
W1
W2
HEAT RELAY 1
HEAT RELAY 2
COOLING
TRANSFORMER
Y2
Y1
G
RC
COOLING
CONTACTOR 1
COOLING
CONTACTOR 2
FAN RELAY
HIGH
LIMIT
HIGH
LIMIT
HEAT
AUTO
OFF
SYSTEM
SWITCH
AUTO
ON
FAN
SWITCH
COOL
HEAT 2
COOL 2
COOL 1
SUBBASE
LOGIC/
CONTROL
CIRCUIT
POWER SUPPLY. PROVIDE DISCONNECT MEANS
AND OVERLOAD PROTECTION AS REQUIRED.
FOR SINGLE TRANSFORMER SYSTEM, JUMPER R AND RC.
NOMINAL 24 Vac POWER MUST BE PRESENT BETWEEN
R AND C FOR THERMOSTAT OPERATION.
AVAILABLE ON T8624D MODELS ONLY.
POWER
SUPPLY
THERMOSTAT
LOGIC
CIRCUIT
1
L1
(HOT)
L2
2
L1
(HOT)
L2 1
2
3
4
1
2
3
4
HEAT 1
5
5

Fig. 7—T8624D 2-stage heat/2-stage cool thermostat with HEAT-AUTO-COOL-OFF system and AUTO-ON

fan switching.