Honeywell CHRONOTHERM III T8611M User Manual page 15

Fig. 7—Restrict wiring to recessed area surrounding terminals.
6
SUBBASE
THERMOSTAT
LOGIC/
LOGIC
CONTROL
CIRCUIT
CIRCUIT
1
POWER SUPPLY. PROVIDE DISCONNECT MEANS AND OVERLOAD PROTECTION AS REQUIRED.
2
POSSIBLE CHECK LED CIRCUITS:
X2
CHECK
FAULT DETECTION
LED
SWITCH
(YELLOW)
X1
SWITCH TO R (POWER) SIDE OF
SYSTEM TRANSFORMER
3
SOME OLDER HEAT PUMP THERMOSTATS USE X FOR COMMON TERMINAL.
4
NOMINAL 24 Vac POWER MUST BE PRESENT BETWEEN R AND C TERMINALS FOR THERMOSTAT OPERATION.
5
RECOMMENDED INTERCONNECT CABLE: 18-GAUGE THERMOSTAT CABLE, 200 ft. [61 m] MAXIMUM LENGTH. ROUTE
INTERCONNECT CABLE AWAY FROM SOURCES OF ELECTRICAL NOISE.
6 DENOTES THERMOSTAT TO SUBBASE INTERCONNECT.
7 APPLICABLE ONLY ON MODEL WITH REMOTE SENSOR.
POWER
SUPPLY
FAN
SWITCH
ON
AUTO
SYSTEM
SWITCH
EM. HT.
HEAT
OFF
AUTO
COOL
HEAT 1
HIGH
LIMIT
S1
S1
S2 S2
S3 S3
5
202905 REMOTE
SENSOR
TO R
X2
CHECK
FAULT DETECTION
LED
SWITCH
(YELLOW)
TO C
X1
SWITCH TO C (COMMON) SIDE
OF SYSTEM TRANSFORMER
R
4
HIGH
LIMIT
3
C
EM. HEAT AUX. HEAT
LED (RED)
LED (GRN)
L
W3
HEAT 3
W2
HEAT 2
E
G
O
C.O.
B
COOL 1
C.O.
STAGE 1 COMPRESSOR
CONTACTOR
Y
STAGE 2 COMPRESSOR
CONTACTOR
Y2
COOL 2
7
X2
CHECK LED
(YELLOW)
X1
TO R
X2
CHECK
SWITCHING
LED
DEVICE
(YELLOW)
24 Vac
TO C
X1
SWITCH IN SECONDARY OF
SEPARATE TRANSFORMER
15
INSTALLATION
1
L1
(HOT)
L2
MONITOR
STAGE 2
HEAT RELAY
EMERGENCY
HEAT RELAY
FAN RELAY
CHANGEOVER
RELAY (COOL)
CHANGEOVER
RELAY (HEAT)
2
L1
(HOT)
1
L2
M1018D
68-0076—1
T8611M