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Fig. 10—T874D/Q674G in standard heating/cooling system.
FALL
H1
H1 ANTICIPATOR
H2
ANTICIPATOR
FALL
H2
RISE
C1
C1
ANTICIPATOR
C2
ANTICIPATOR
RISE
1
C2
2
Fig. 11—Typical Q674 terminal designations. The thermostat used determines the number of connections.
STAGE 1
HEATING
RELAY
STAGE 2
HEATING
RELAY
STAGE 3
HEATING
RELAY
CLOGGED
FILTER
SWITCH
SYSTEM
MONITOR
OUTDOOR
THERMISTOR
HEATING DAMPER
MOTOR (OR
CHANGEOVER
VALVE)
EMERGENCY
HEAT
RELAY
LED
2
M954
NO FAN
SWITCH
SYSTEM SWITCH
OFF
AUTO
POWER SUPPLY. PROVIDE DISCONNECT MEANS AND OVERLOAD PROTECTION AS REQUIRED.
JUMPER RC, RH FOR SINGLE TRANSFORMER.
RC
O
1
RH
W2
1
ADD JUMPER (RH-RC) FOR HOOKUP USING COMMON TRANSFORMER.
POWER
2
PROVIDE DISCONNECT MEANS AND OVERLOAD PROTECTION AS REQUIRED.
SUPPLY
RH
W1
2
W2
B
O
Y2
Y1
RC
L
W3
Y1
Y2
W1
X
G
B
X1
E
T
Q674
SUBBASE
6
L1
(HOT)
L2
1
HEAT RELAY 1
HEAT RELAY 2
COMPRESSOR
CONTACTOR 2
1
COMPRESSOR
L2
CONTACTOR 1
L1
(HOT)
M3726
COOLING DAMPER
MOTOR (OR
CHANGEOVER
VALVE)
STAGE 1
COOLING
RELAY
STAGE 2
COOLING
RELAY
COOLING
FAN RELAY
COIL
POWER
SUPPLY
2
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