Honeywell Q674A-E - Manual (Page 4)

4
60-1165—6
Fig. 8—T874A-D/Q674A in standard heating/cooling system.
Fig. 9—T874C,D/Q674B in standard heating/cooling system with separate transformers for heating and
cooling.
H1
FALL
L1
(HOT)
L2
1
RH
W1
W2
O
G
Y2
Y1
RC
HEAT RELAY 2
HEAT RELAY 1
HEAT
OFF
COOL
SYSTEM
SWITCH
H1 ANTICIPATOR
C1 ANTICIPATOR
AUTO
ON
FAN
SWITCH
2
1 POWER SUPPLY. PROVIDE DISCONNECT MEANS AND OVERLOAD
PROTECTION AS REQUIRED.
JUMPER RH, RC FOR SINGLE TRANSFORMER.
2
M933C
B
HEAT CHANGEOVER
VALVE
L1
(HOT)
L2
1
COOL CHANGEOVER
VALVE
FAN RELAY
COMPRESSOR
CONTACTOR 2
COMPRESSOR
CONTACTOR 1
1
4
6
8
9
10
11
H2
FALL
C2 ANTICIPATOR
RISE
RISE
C1
C2
X1
3 OPTIONAL LED ON SOME MODELS.
THERMOSTAT SUBBASE SYSTEM COMPONENTS
3
H2 ANTICIPATOR