NOTHERM T8621A User guide

13 68-0058—1
T8621A,C,D
INSTALLATION
Fig. 12—T8621C,D single stage heat pump with heating changeover. HEAT-AUTO-COOL-OFF system and
AUTO-ON fan switching.
M1547C
SYSTEM
TRANSFORMER
R
C
W1
W2
Y2
Y1
G
RC
FAN RELAY
HIGH
LIMIT
HIGH
LIMIT
L1
(HOT)
L2
HEAT
AUTO
COOL
SYSTEM
SWITCH
AUTO
ON
FAN
SWITCH
T8621D ONLY.
DENOTES THERMOSTAT TO SUBBASE CONNECTIONS.
NOTE: SET CYCLE RATE TO HOT WATER SETTING (3 cph).
THERMOSTAT DOES NOT PROVIDE MINIMUM OFF TIME IN
HEATING.
1
S1
S2
S3
S1
S2
S3
202905 REMOTE
SENSOR
3
OFF
COMPRESSOR
CONTACTOR
HEATING
CHANGEOVER
H1
H2
C1
C2
1
2
5
SUBBASE
LOGIC/
CONTROL
CIRCUIT
POWER SUPPLY. PROVIDE DISCONNECT MEANS AND OVERLOAD
PROTECTION AS REQUIRED.
APPLICABLE ONLY ON T8621 MODEL WITH REMOTE SENSOR.
RECOMMENDED INTERCONNECT CABLE: 18-GAUGE THERMOSTAT
CABLE, 200 ft. [61 m] MAXIMUM LENGTH. ROUTE INTERCONNECT
CABLE AWAY FROM SOURCES OF ELECTRICAL NOISE.
3
4
5
4
2
POWER
SUPPLY
THERMOSTAT
LOGIC CIRCUIT