69-0268—11 4
T874G,R MULTISTAGE HEAT PUMP THERMOSTATS AND Q674F,J,L SUBBASES
H1
FALL
H2
FALL
CO
RISE
C1 RISE
L1
(HOT)
L2
1
2
1
2
POWER SUPPLY. PROVIDE DISCONNECT MEANS AND OVERLOAD PROTECTION AS REQUIRED.
REMOVE JUMPER FOR INDEPENDENT CONTROL OF W1 AND E TERMINALS.
THERMOSTAT SUBBASE SYSTEM COMPONENTS
H1
ANTICIPATOR
H2 ANTICIPATOR
C1
ANTICIPATOR
SYSTEM
SWITCH
FAN
SWITCH
AUTO
ON
OFF
EM. HT.
AUTO
EM. HT.
RELAY
COOL CHANGEOVER
VALVE
COMPRESSOR
CONTACTOR
M1629
1
2
4
6
8
9
10
Y
C
X
E
W1
R
G
O
AUX. HT.
LED
(YELLOW)
CHECK
LED
(RED)
SYSTEM
LED
(GREEN)
4R
HPS 4R
5R 4R
4R
SEQ 1
SEQ 2
3R
FAN RELAY

Fig. 4. Internal schematic and typical hookup for T874G/Q674J in heat pump system. Includes AUX. HT., CHECK

and SYSTEM LEDs.