Honeywell Q674 Installation Instructions Manual page 4

Fig. 6—Internal schematic and typical wiring diagram for T874N and Q674F.
H1
ANTICIPATOR
H1
FALL
H2
ANTICIPATOR
H2
FALL
RISE
C1
ANTICIPATOR
C1
C0
1 POWER SUPPLY. PROVIDE DISCONNECT MEANS AND OVERLOAD PROTECTION AS REQUIRED.
60-1147-4
FAN SWITCH
AUTO
ON
SYSTEM
SWITCH
OFF
EM. HT.
HEAT
AUTO
COOL
W1
DEFROST
RELAY
EM.HT. RELAY
CONTACT
EM.HT. RELAY
CONTACT
W3
G
R
W2
E
EM. HEAT
LED (RED)
X
CHECK
LED
(GREEN)
L
HIGH
PRESSURE
SWITCH
Y
4
OUTDOOR
THERMOSTAT REVERSING
VALVE
HEAT
RELAY 2
HEAT
RELAY 3
FAN RELAY
1
L1
HOT
L2
HEAT
RELAY 1
EM. HEAT
RELAY
OPTIONAL
COMPRESSOR
FAILURE DEVICE
COMPRESSOR
CONTACTOR
M3686