Honeywell T874 - Page 149

T874 MULTISTAGE THERMOSTATS AND Q674 SUBBASES
149 60-2485—8
Fig. 131. Schematic and hookup of T874R with Q674L. Used in heat pump applications.
H2
FALL
H1
FALL
C1
L1
(HOT)
L2
1
1
2
2
POWER SUPPLY. PROVIDE DISCONNECT MEANS AND OVERLOAD PROTECTION AS REQUIRED.
FOR Q674L1454, IS "OFF".
THERMOSTAT
SUBBASE
SYSTEM COMPONENTS
H1/C1 ANTICIPATOR
H2 ANTICIPATOR
SYSTEM
SWITCH
FAN
SWITCH
AUTO
ON
SUPL. HT.
HEAT
COOL
COOL CHANGEOVER
VALVE
COMPRESSOR
CONTACTOR
FAN RELAY
M472
3
2
3
4
6
R
W2
L
SUPL. HT.
LED (RED)
C
G
O
E
Y
HCR 1
HCR 2
HCR 2
HCR 3
ODT
HCR 1
RESET
HEATER