Honeywell T874 Product Data page 204

T874 MULTISTAGE THERMOSTATS AND Q674 SUBBASES
THERMOSTAT
H1
FALL
FALL
POWER SUPPLY. PROVIDE DISCONNECT MEANS AND OVERLOAD PROTECTION AS REQUIRED.
1
2 TERMINAL LABELED C/X ON SOME MODELS.
3 W3 TERMINAL AVAILABLE ON SOME MODELS ONLY.
Fig. 218. Schematic and hookup of T874R with Q674L. Used in heat pump applications.
60-2485—8
2
H1/C1
ANTICIPATOR
FAN
3 SWITCH
AUTO
C1
ON
4
H2
ANTICIPATOR
H2
6
SUBBASE
EM. HT.
LED (RED)
W3
AUX. HT.
LED (GRN)
W2
SYSTEM
SWITCH
EM. HT.
HEAT
OFF
COOL
204
SYSTEM COMPONENTS
R
L
AUX. HT.
3 RELAY
2
X
AUX. HT.
RELAY
FAN RELAY
G
COOL CHANGEOVER
VALVE
O
E
EM. HT. RELAY
Y
COMPRESSOR
CONTACTOR
B
"B" RELAY
M3683A
L1
(HOT)
L2
1