Honeywell T874 Product Data page 168

T874 MULTISTAGE THERMOSTATS AND Q674 SUBBASES
THERMOSTAT
H1 ANTICIPATOR
H1 FALL
FALL
H2
RISE
CO
RISE
C1
Fig. 159. Schematic and hookup of T874G with Q674J. Used in heat pump applications.
THERMOSTAT
FALL
H1
H1 ANTICIPATOR
H2 ANTICIPATOR
FALL
H2
RISE
CO
C1 ANTICIPATOR
RISE
C1
Fig. 160. Schematic and hookup of T874G with Q674J. Used in heat pump applications.
60-2485—8
1
FAN SWITCH
AUTO
2
OFF
4
SYSTEM
6
SWITCH
H2 ANTICIPATOR
8
EM.HT.
9
AUTO
OFF
C1 ANTICIPATOR
10
1
POWER SUPPLY. PROVIDE DISCONNECT MEANS AND OVERLOAD PROTECTION AS REQUIRED.
2
3
4
5
6
8
9
10
1 POWER SUPPLY. PROVIDE DISCONNECT MEANS AND OVERLOAD PROTECTION AS REQUIRED.
SUBBASE
O
L1
(HOT)
G
R
W
OUTDOOR
THERMOSTAT
E
EM. HT. LED
(RED)
X
Y
SUBBASE
FAN
SWITCH
AUTO
ON
SYSTEM
SWITCH
EM. HT.
AUTO
OFF
168
SYSTEM COMPONENTS
COOL CHANGEOVER VALVE
L2
1
FAN RELAY
HEAT RELAY
CONTACT
AUX. HT. RELAY
HEAT RELAY EM. HT.
CONTACT RELAY
COMPRESSOR
LIMIT CONTACTOR
M5722
SYSTEM COMPONENTS
O
COOL CHANGEOVER VALVE
G
FAN RELAY
R
W
AUX. HT. RELAY
X
EM. HT. RELAY
EM. HT.
LED (RED)
B
COMPRESSOR
CONTACTOR
Y
L1
(HOT)
L2
1
M5723