T874 MULTISTAGE THERMOSTATS AND Q674 SUBBASES
60-2485—8 114
Fig. 79. Schematic and hookup of T874G,H with Q674C. Used in standard applications. Fig. 80. Schematic and hookup of T874D with Q674E. Used in standard applications.
O
1
THERMOSTAT SUBBASE SYSTEM COMPONENTS
R1
G
R2
H1 ANTICIPATOR
CO
RISE
H1 FALL
FALL
H2
C1
C1
ANTICIPATOR
POWER SUPPLY. PROVIDE DISCONNECT MEANS AND OVERLOAD
PROTECTION AS REQUIRED.
SETBACK CONTACT ON Q674C1124.
Y
1
6
9
10
4
8
AUTO
ON
FAN
SWITCH
SYSTEM
SWITCH
OFF COMPRESSOR
CONTACTOR
AUTO
X
L1
(HOT
)
1
L2
COOL
CHANGEOVER
VALVE
23
RESET
FAN RELAY
SETBACK
CONTACT
RISE
RESET
LED (RED)
H2 ON T874G. M7027
3
2
H1
FALL
FALL
L1
(HOT
)
L21
2
2
1POWER SUPPLY. PROVIDE DISCONNECT MEANS AND OVERLOAD PROTECTION AS REQUIRED.
OPTIONAL FIELDWIRE JUMPER TO ALLOW SINGLE SYSTEM TRANSFORMER.
THERMOSTAT SUBBASE SYSTEM COMPONENTS
M5997
HEAT
RELAY 1 CONTACTOR
COMPRESSOR 1
FAN RELAY
HEAT RELAY 2
COMPRESSOR
FAULT COMPRESSOR
CONTACTOR 2
SERVICE
LED (RED)
SYSTEM
SWITCH OFF
HEAT
AUTO
COOL
C2 ANTICIPATOR
C1 ANTICIPATOR
C2
RISE
RISE
C1
H2 ANTICIPATOR
H1 ANTICIPATOR
H2
4
6
8
10
11 Y2
Z
C
W2
RC
G
Y1
W1
FAN SWITCH
AUTO
ON
1
RH
9