Bryant T874 Thermostat User Manual


 
T874 MULTISTAGE THERMOSTATS AND Q674 SUBBASES
60-24858208
Fig. 224. Schematic and hookup of T874A,D with Q674E. Used in standard applications.
M5927
H1
FALL
L1
(HOT)
L2
1
L1
(HOT)
L2
1
THERMOSTAT SUBBASE
SYSTEM COMPONENTS
1
4
6
8
9
10
11
FAN
SWITCH
SYSTEM
SWITCH
AUTO
ON
OFF
HEAT
AUTO
COOL
SERVICE
LED (RED)
COOL CHANGEOVER VALVE
COMPRESSOR CONTACTOR #2
HEAT RELAY #2
FAN RELAY
COMPRESSOR CONTACTOR #1
HEAT CHANGEOVER VALVE
HEAT RELAY #1
H1
ANTICIPATOR
H2
ANTICIPATOR
C1
C2
RISE
RISE
FALL
POWER SUPPLY. PROVIDE DISCONNECT MEANS AND OVERLOAD PROTECTION AS REQUIRED.
1
CONTROL MODULE
H2
B
W1
Y1
G
RC
W2
RH
A
Y2
O
SYSTEM MONITOR