Bryant T874 Thermostat User Manual


 
T874 MULTISTAGE THERMOSTATS AND Q674 SUBBASES
105 60-24858
Fig. 61. Schematic and hookup of T874C with Q674N. Used in evaporative cooler applications.
Fig. 62. Schematic and hookup of T874F with Q674B. Used in wood/coal applications.
L1
(HOT)
L2
EVAPORATOR
RELAY
ELEC. HT. RELAY
FAN RELAY
COMPRESSOR
CONTACTOR
CHANGEOVER
RELAY
O
Y2
W2
G
R
H2
ANTICIPATOR
AUTO
ON
FAN
SWITCH
H1 ANTICIPATOR
C1
RISE
FALL
H2
FALL
H1
SYSTEM
SWITCH
EVAP.
HEAT
COOL
OFF
1
POWER SUPPLY. PROVIDE DISCONNECT MEANS AND OVERLOAD PROTECTION AS REQUIRED.
C1
ANTICIPATOR
Y1
M2862
1
THERMOSTAT SUBBASE
SYSTEM COMPONENTS
1
4
6
8
9
10
L1
(HOT)
L2
1
FAN RELAY
SYSTEM
SWITCH
OFF
H2 ANTICIPATOR
H1
H2
FALL
1
POWER SUPPLY. PROVIDE DISCONNECT MEANS
AND OVERLOAD PROTECTION AS REQUIRED.
M3723A
AUTO
ON
FAN SWITCH
R
COMPRESSOR
CONTACTOR
G
W2
H1 ANTICIPATOR
X2
AUX. HT. RELAY
HEAT
X1
EXTERNAL COOLING
THERMOSTAT
(SUCH AS T87 F)
COOL
W1
R
Y
C
WOOD/COAL
RELAY
FALL
YELLOW
GREEN
THERMOSTAT
SUBBASE SYSTEM COMPONENTS
1
4
8
9
10