60-1147-45
Fig. 7—Internal schematic and typical wiring diagram for T874R and Q674L.
L1
HOT
L2
1
X2
W2
EM. HEAT
LED (RED)
AUX. HEAT
LED (GREEN)
HIGH LIMIT
SWITCH
FAN RELAY
G
EM. HEAT
RELAY
COMPRESSOR
CONTACTOR
Y
E
SYSTEM
SWITCH
EM. HT.
HEAT
OFF
COOL
H1/C1
ANTICIPATOR
H1
H2
H2
ANTICIPATOR
1
POWER SUPPLY. PROVIDE DISCONNECT MEANS
AND OVERLOAD PROTECTION AS REQUIRED.
M3685
FALL
R
FALL
L
C1
HEAT
RELAY 1
HEAT
CONTACTOR 3
EM.HT. RELAY
CONTACT
OUTDOOR
THERMOSTAT
HEAT
CONTACTOR 2
AUTO
ON
FAN SWITCH
O
X1
B
W3
OPTIONAL COMP
FAILURE DEVICE
DEFROST
RELAY
DEFROST
RELAY
REVERSING
VALVE
EM.HT. RELAY
CONTACT
COOL RELAY
HIGH
PRESSURE
SWITCH
LOW
AMBIENT
CUTOFF
4. Turn over thermostat base and note the spring fingers
that engage the subbase contacts. Make sure the spring
fingers are not bent flat. Flat fingers prevent proper electrical
contact with the subbase.
5. Set the second stage heat anticipation indicator to
match the current rating of the controlled equipment. See
Heat Anticipator Setting section. The first stage heat antici-
pator and the cooling anticipator are nonadjustable.
6. Note the two tabs on the top inside edge of the
thermostat base. The tabs fit into corresponding slots on top
of the subbase. Mount the thermostat on the subbase.
7. Align the two captive mounting screws in the thermo-
stat base with the posts on the subbase (Fig. 9). Tighten both
screws. Do not overtighten screws because damage to
subbase posts can result.
Fig. 8—LED space location and adjustable lever
stops.
TIGHTENING SCREW
ADJUSTABLE STOPS
LED SPACE
M7557
