Honeywell T874 - Schematic and Hookup of T874 D with Q674 B. Used in Standard Applications

T874 MULTISTAGE THERMOSTATS AND Q674 SUBBASES
60-2485—8 98
Fig. 48. Schematic and hookup of T874D with Q674B. Used in standard applications.
H1
FALL
W1
G
W2
B
RH
X1
O
FAN RELAY
HEAT RELAY 1
HEAT
OFF
COOL
SYSTEM
SWITCH
H1 ANTICIPATOR
C1 ANTICIPATOR
AUTO
ON
FAN
SWITCH
2
1
POWER SUPPLY. PROVIDE DISCONNECT MEANS AND OVERLOAD
PROTECTION AS REQUIRED.
CLOGGED FILTER, SERVICE SWITCH.
M2905
THERMOSTAT
SUBBASE
SYSTEM COMPONENTS
RC
HEAT CHANGEOVER
VALVE
L1
(HOT
)
L2
1
COOL CHANGEOVER
VALVE
COMPRESSOR
CONTACTOR 2
COMPRESSOR
CONTACTOR 1
1
4
6
8
9
10
11
H2
FALL
C2 ANTICIPATOR
RISE
RISE
C1
C2
Y1
Y2
HEAT RELAY 2
EXTERNAL
FAN SWITCH
2
L1
(HOT
)
L2
1
FILTER
LED (RED)
H2
ANTICIPATOR