T874 MULTISTAGE THERMOSTATS AND Q674 SUBBASES
60-24858160
Fig. 149. Schematic and hookup of T874C with Q674F. Used in heat pump applications.
THERMOSTAT SUBBASE SYSTEM COMPONENTS
H1
FALL
H1 ANTICIPATOR
1
H2
FALL
H2
ANTICIPATOR
W1
EMR4 2R
1R
5R
3R
Y1
G
EMR4
EMR2
THERMAL SWITCHES
FOR HEATING
ELEMENTS HTR 1
C1
RISE
HTR 3
HTR 2
OUTDOOR
THERMOSTAT
EMR3
L1
(HOT)
L2
1
L1
(HOT) L2
1
C2
RISE
8
3
C1
ANTICIPATOR
C2
ANTICIPATOR
9
11
10
EM. HT. LED
RC
X1
RH
EMR1
EMR1
Z
EM. HT. RELAY
2
1
2
3
POWER SUPPLY. PROVIDE DISCONNECT MEANS
AND OVERLOAD PROTECTION AS REQUIRED.
OPTIONAL FIELD WIRE JUMPER TO ALLOW
SINGLE SYSTEM TRANSFORMER.
FOR Q674F1048, DELETE C2 STAGE.
M8380
SYSTEM
SWITCH
OFF
EM. HT.
HEAT
AUTO
COOL
E
FAN
SWITCH
AUTO
ON
W2
6
4
3R1
4R2 2R2