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T874 MULTISTAGE THERMOSTATS AND Q674 SUBBASES
60-2485—8
164
Fig. 154. Schematic and hookup of T874G with Q674F. Used in heat pump applications.
H2
FALL
Y
R
COM
G
W
O
EH
O
G
Y
A
H
E
W2
R
1
COMPRESSOR
CONTACTOR
EM. HT.
HEAT
AUTO
COOL
COMP. FAULT
LED (YELLOW)
SYSTEM
SWITCH
FAN
SWITCH
AUTO
ON
1
POWER SUPPLY. PROVIDE DISCONNECT MEANS AND
OVERLOAD PROTECTION AS REQUIRED.
OPTIONAL FIELD WIRE JUMPER TO CYCLE W2 WITH H1
IN EM. HEAT(FASTER RESPONSE).
2
H2 ANTICIPATOR
2
X
C
DF
RS
FAN
L1
(HOT)
L2
EM. HT. RELAY
FAN
REVERSING
SOLENOID
T6031
REFRIGERATION
TEMPERATURE
CONTROLLER
EM. HT. RELAY
CONTACT 1
EM. HT.
L1
(HOT)
L2
EM. HT.
LED (RED)
H1 ANTICIPATOR
H1
FALL
H1 ANTICIPATOR
CO
RISE
C1
RISE
SEQUENTIAL
RELAY
M2858
R8233B
THERMOSTAT
SUBBASE
SYSTEM COMPONENTS
1
2
6
4
8
9
10
OFF