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
1POWER 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
1POWER 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
CWOOD/COAL
RELAY
FALL
YELLOW
GREEN
THERMOSTAT SUBBASE SYSTEM COMPONENTS
1
4
8
9
10