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T874 MULTISTAGE THERMOSTATS AND Q674 SUBBASES
60-2485—8152
Fig. 135. Schematic and hookup of T874R with Q674L. Used in heat pump applications.
Fig. 136. Schematic and hookup of T874R with Q674L. Used in heat pump applications.
H2
FALL
H1
FALL
C1
L1
(HOT)
L2
1
R
W2
L
C
G
O
E
Y
2
3
4
6
POWER SUPPLY. PROVIDE DISCONNECT MEANS AND OVERLOAD
PROTECTION AS REQUIRED.
1
THERMOSTAT
SUBBASE SYSTEM COMPONENTS
FAN
SWITCH
AUTO
ON
SYSTEM
SWITCH
SUPL. HT.
HEAT
OFF
COOL
M2017
HCR 1
ODT
HCR 1
HCR 2
FAN RELAY
COOL
CHANGEOVER VALVE
HCR 2
HCR 3
COMPRESSOR
CONTACTOR
SUPL. HT.
LED (RED)
H1/C1
ANTICIPATOR
RESET
HEATER
H2 ANTICIPATOR
H2
FALL
H1
FALL
C1
L1
(HOT)
L2
1
G
W
U
B
F
R
T
X2
O
Y
2
1
3
4
5
6
FAN RELAY
AUX. HEAT
RELAY
COMP.
FAILURE
O.D.
STAT
C815A OUTDOOR
THERMISTOR
COOL CHANGEOVER
VALVE
COMPRESSOR
CONTACTOR
POWER SUPPLY. PROVIDE DISCONNECT MEANS AND OVERLOAD
PROTECTION AS REQUIRED.
FIELD REMOVABLE JUMPER
1
2
2
THERMOSTAT
SUBBASE SYSTEM COMPONENTS
RESET
FAN
SWITCH
AUTO
ON
AUX. HT.
LED (GRN)
EM. HT.
LED (RED)
SYSTEM
SWITCH
EM. HT.
HEAT
OFF
COOL
M2012
C1
ANTICIPATOR
H1
ANTICIPATOR