Honeywell CHRONOTHERM T8621A User Manual page 14

T8621A,C,D
INSTALLATION
Fig. 13—T8621C,D single stage heat pump with cooling changeover. HEAT-AUTO-COOL-OFF system and
AUTO-ON fan switching.
THERMOSTAT
LOGIC CIRCUIT
1
POWER SUPPLY. PROVIDE DISCONNECT MEANS AND OVERLOAD
PROTECTION AS REQUIRED.
2
ADD RELAY (SPDT) TO ACCOMMODATE COOLING CHANGEOVER.
3
APPLICABLE ONLY ON T8621D MODELS WITH REMOTE SENSOR.
6
POWER
SUPPLY
SUBBASE
LOGIC/
CONTROL
CIRCUIT
HIGH
LIMIT
HIGH
LIMIT
H1
SYSTEM
SWITCH
H2
HEAT
AUTO
COOL
OFF
C2
C1
FAN
SWITCH
AUTO
ON
4
RECOMMENDED INTERCONNECT CABLE: 18-GAUGE THERMOSTAT CABLE,
200 ft. [61 m] MAXIMUM LENGTH. ROUTE INTERCONNECT CABLE AWAY
FROM SOURCES OF ELECTRICAL NOISE.
5 T8621D ONLY.
6 DENOTES THERMOSTAT TO SUBBASE INTERCONNECTION.
NOTE: SET CYCLE RATE TO HOT WATER SETTING (3 cph). THERMOSTAT
DOES NOT PROVIDE MINIMUM OFF TIME IN HEATING.
14
L1
(HOT)
1
SYSTEM
TRANSFORMER
R
C
K
COOLING
RELAY K
W1
CHANGE-
OVER
W2
COMPRESSOR
CONTACTOR
5
Y2
Y1
FAN RELAY
G
RC
3
S1 S1
S2 S2
S3 S3
202905 REMOTE
4
SENSOR
M1548C
L2