Honeywell T874 - Page 170

T874 MULTISTAGE THERMOSTATS AND Q674 SUBBASES
60-2485—8 170
Fig. 162. Schematic and hookup of T874G with Q674J. Used in heat pump applications.
H1
FALL
EM. HT.
LED (RED)
L1
(HOT)
L2
1
AUX. HT. LED
(GREEN)
F
M5725
POWER SUPPLY. PROVIDE DISCONNECT MEANS AND OVERLOAD PROTECTION AS REQUIRED.
1
SYSTEM COMPONENTSSUBBASETHEROMSTAT
B
W
H2
FALL
CO
RISE
C1
RISE
O
G
T
R
1
2
3
4
5
6
8
9
10
Y
X2
C1
ANTICIPATOR
RESET HEATER
H1 ANTICIPATOR
SYSTEM SWITCH
EM. HT.
AUTO
OFF
FAN SWITCH
AUTO
ON
C815A OUTDOOR
THERMISTOR
FAN RELAY
COOL
CHANGEOVER VALVE
OUTDOOR
THERMOSTAT
AUX. HT. RELAY
EM. HT. RELAY
COMPRESSOR
CONTACTOR