Honeywell T874 - Schematic and Hookup of T874 A-D with Q674 A. Used in Standard Applications; Schematic and Hookup of T874 D, E, F with Q674 R. Used in Standard Applications

T874 MULTISTAGE THERMOSTATS AND Q674 SUBBASES
60-2485—8 110
Fig. 71. Schematic and hookup of T874A-D with Q674A. Used in standard applications.
Fig. 72. Schematic and hookup of T874D,E,F with Q674C. Used in standard applications.
H1
FALL
L1
(HOT
)
L2
1
RH
W1
W2
G
Y2
Y1
RC
HEAT RELAY 2
HEAT RELAY 1
HEAT
AUTO
COOL
SYSTEM
SWITCH
H1
ANTICIPATOR
C1 ANTICIPATOR
AUTO
ON
FAN SWITCH
2
1
POWER SUPPLY. PROVIDE DISCONNECT MEANS AND OVERLOAD
PROTECTION AS REQUIRED.
JUMPER RH, RC FOR SINGLE TRANSFORMER.
2
M932B
L1
(HOT
)
L2
1
FAN RELAY
COMPRESSOR
CONTACTOR 2
COMPRESSOR
CONTACTOR 1
1
4
6
8
9
10
11
H2
FALL
C2 ANTICIPATOR
RISE
RISE
C1
C2
X1
3
OPTIONAL LED ON SOME MODELS.
THERMOSTAT
SUBBASE
SYSTEM COMPONENTS
3
H2 ANTICIPATOR
CHECK
L1
(HOT
)
L2
1
H2 ANTICIPATOR
H1 ANTICIPATOR
C1 ANTICIPATOR
C2 ANTICIPATOR
FALL
H1
W2
W1
B
G
RH
1
2
3
3
2
2
POWER SUPPLY. PROVIDE DISCONNECT MEANS AND OVERLOAD
PROTECTION AS REQUIRED.
JUMPER TERMINALS RC-RH FOR SINGLE SYSTEM TRANSFORMER ONLY.
B,O TERMINALS ON SOME MODELS.
AUTO
ON
FAN
SWITCH
SYSTEM
SWITCH
AUTO
OFF
RISE
C2
C1
FALL
RISE
H2
O
Y2
Y1
RC
HEAT DAMPER
COOL DAMPER
FAN RELAY
COMPRESSOR
CONTACTOR 2
COMPRESSOR
CONTACTOR 1
L1
(HOT
)
L2
1
HEAT RELAY 1
HEAT RELAY 2
M5122A
THERMOSTAT
SUBBASE SYSTEM COMPONENTS
1
4
6
8
9
10
11