Honeywell T874 Product Data page 152

T874 MULTISTAGE THERMOSTATS AND Q674 SUBBASES
THERMOSTAT
H1/C1
ANTICIPATOR
H1
C1
RESET
HEATER
FALL
H2 ANTICIPATOR
H2
FALL
1 POWER SUPPLY. PROVIDE DISCONNECT MEANS AND OVERLOAD
PROTECTION AS REQUIRED.
Fig. 135. Schematic and hookup of T874R with Q674L. Used in heat pump applications.
THERMOSTAT
C1
ANTICIPATOR
H1
C1
FALL
H2
FALL
1
FIELD REMOVABLE JUMPER
2 POWER SUPPLY. PROVIDE DISCONNECT MEANS AND OVERLOAD
PROTECTION AS REQUIRED.
Fig. 136. Schematic and hookup of T874R with Q674L. Used in heat pump applications.
60-2485—8
FAN
SWITCH
AUTO
2 ON
3
4
SYSTEM
SWITCH
SUPL. HT.
6
HEAT
OFF
COOL
1
H1
ANTICIPATOR
2
3
4
RESET
5
6
SUBBASE
SUPL. HT.
LED (RED)
SUBBASE
AUX. HT.
FAN
LED (GRN)
SWITCH
AUTO
EM. HT.
LED (RED)
ON
SYSTEM
SWITCH
EM. HT.
HEAT
OFF
COOL
152
SYSTEM COMPONENTS
R
W2
HCR 1
L
ODT HCR 1
C
G
FAN RELAY
O
COOL
CHANGEOVER VALVE
E
HCR 3
HCR 2
Y
COMPRESSOR
CONTACTOR
SYSTEM COMPONENTS
G
FAN RELAY
W
AUX. HEAT
1
U
RELAY
B
COMP.
F
FAILURE
R
T
X2
C815A OUTDOOR
O.D.
THERMISTOR
STAT
COOL CHANGEOVER
VALVE
O
COMPRESSOR
CONTACTOR
Y
L1
(HOT)
L2 1
HCR 2
M2017
2
L2
L1
(HOT)
M2012