Honeywell T874 Product Data page 167

THERMOSTAT
H1 ANTICIPATOR
H1
FALL
H2
H2 ANTICIPATOR
FALL
CO
RISE
C1 ANTICIPATOR
C1
RISE
10
1
POWER SUPPLY. PROVIDE DISCONNECT MEANS
AND OVERLOAD PROTECTION AS REQUIRED.
Fig. 158. Schematic and hookup of T874G with Q674F. Used in heat pump applications.
SUBBASE
1
FAN
2
SWITCH
AUTO
ON
4
6
SYSTEM
SWITCH
OFF
EM. HT.
8
HEAT
AUTO
9
COOL
2
B TERMINAL ON SELECT MODELS.
167
T874 MULTISTAGE THERMOSTATS AND Q674 SUBBASES
L1
(HOT) L2
1
O
E
G
2
B
R
W2
L 1
EM. HT. LED
(RED)
X
AUX. HT. LED (GREEN)
Y
COMPRESSOR CONTACTOR
SYSTEM COMPONENTS
COOL CHANGEOVER VALVE
EM. HT. RELAY
FAN RELAY
HEAT CHANGEOVER VALVE
AUX. HT. RELAY
COMPRESSOR
FAILURE
M5721
60-2485—8