Bryant T874 Thermostat User Manual


 
T874 MULTISTAGE THERMOSTATS AND Q674 SUBBASES
171 60-24858
Fig. 163. Schematic and hookup of T874G with Q674C. Used in standard applications.
H1
FALL
H2
FALL
CO
FALL
C1
RISE
L1
(HOT)
L2
1
1
1
1
2
3
POWER SUPPLY. PROVIDE DISCONNECT MEANS AND OVERLOAD
PROTECTION AS REQUIRED.
H2 HAS 10¡F FIXED SETBACK FROM H1 ON T874G1485, 0-12¡F
ADJUSTABLE ON T874G1535.
RESET IN MOMENTARY POSITION, SPRING RETURN TO OFF UPON
SWITCH RELEASE.
THERMOSTAT
SUBBASE
SYSTEM COMPONENTS
1
4
6
8
9
10
C1
ANTICIPATOR
H2
ANTICIPATOR
H1
ANTICIPATOR
FAN
SWITCH
AUTO
ON
SYSTEM
SWITCH
AUTO
OFF
RESET
RESET CIRCUIT
RESET CIRCUIT
COMPRESSOR
RELAY
SERVICE LED (RED)
ON LED (YELLOW)
COOL
CHANAGEOVER VALVE
HEAT RELAY 2
FAN RELAY
HEAT RELAY 1
HEAT DAMPER
C
A
X
Y
S2
O
S1
R
W2
G
W1
B
M1820C