T874 MULTISTAGE THERMOSTATS AND Q674 SUBBASES
199 60-2485—8
Fig. 211. Schematic and hookup of T874G with Q674F. Used in standard applications. Fig. 212. Schematic and hookup of T874A with Q674E. Used in standard applications.
H1
FALL G
R
L
X
W2
FAN RELAY
W1 RELAY
EM. HT.
OFF
AUTO
SYSTEM
SWITCH
H1 ANTICIPATOR
C1
ANTICIPATOR
AUTO
ON
FAN SWITCH
1POWER SUPPLY. PROVIDE DISCONNECT MEANS AND OVERLOAD PROTECTION AS REQUIRED. M2989
THERMOSTAT SUBBASE SYSTEM COMPONENTS
W1
COMPRESSOR
FAULT
AUX. HT. RELAY
3
4
6
8
10
H2
FALL
RISE C1
L1
(HOT
)
L2
1
H2
ANTICIPATOR
2
EM. HT.
LED (RED)
Y1
AUX. HT.
LED
(GREEN)
COOL
HEAT
COMPRESSOR
CONTACTOR
H1
FALL
W1
W2
HEAT RELAY 1
H1 ANTICIPATOR
C1 ANTICIPATOR
1POWER SUPPLY. PROVIDE DISCONNECT MEANS AND OVERLOAD PROTECTION AS REQUIRED.
RC -RH REMOVABLE JUMPER WHEN SPECIFIED. M2990
THERMOSTAT SUBBASE SYSTEM COMPONENTS
COMPRESSOR
CONTACTOR 2
COMPRESSOR
CONTACTOR 1
1
6
8
9
10
11
H2
FALL
C2 ANTICIPATOR
RISE
RISE
C1
C2
Y1
Y2
HEAT RELAY 2
L1
(HO
T)
L2
1
H2
ANTICIPATOR
L1
(HO
T)
L2
1
RC
RH
2
4
2
G
FAN RELAY
HEAT
AUTO
COOL
SYSTEM
SWITCH
AUTO
ON
FAN
SWITCH
OFF