Honeywell T874 Product Data page 159

THERMOSTAT
H1
H1
ANTICIPATOR
FALL
H2
ANTICIPATOR
FALL
H2
CO
RISE
C1
ANTICIPATOR
RISE
C1
1 POWER SUPPLY. PROVIDE DISCONNECT MEANS AND OVERLOAD
PROTECTION AS REQUIRED.
2
CONNECT TO Y OR W TERMINAL WITH FACTORY INSTALLED JUMPER.
Fig. 147. Schematic and hookup of T874G with Q674F. Used in heat pump applications.
THERMOSTAT
H1 ANTICIPATOR
FALL
H1
FALL
H2 ANTICIPATOR
H2
RISE
CO
C1
ANTICIPATOR
C1
RISE
1
POWER SUPPLY. PROVIDE DISCONNECT MEANS AND OVERLOAD PROTECTION AS REQUIRED.
Fig. 148. Schematic and hookup of T874G with Q674F. Used in heat pump applications.
2
FAN
3
SWITCH
AUTO
4
ON
5
6
SYSTEM
SWITCH
OFF
8
COOL
AUTO
9
HEAT
EM. HT.
10
1
FAN
SWITCH
2
AUTO
ON
4
6
SYSTEM
SWITCH
OFF
8
EM. HT.
HEAT
9
AUTO
COOL
10
159
T874 MULTISTAGE THERMOSTATS AND Q674 SUBBASES
SUBBASE
SERVICE
LED (RED)
AUX. HT.
LED (GRN)
EM. HT.
LED (YEL)
JUMPER FACTORY INSTALLED.
3
SUBBASE
EM. HT.
LED
(RED)
SYSTEM COMPONENTS
A
MODE SIGNAL
1
3
2
G
FAN RELAY
R
2
S
W3
HEAT RELAY 2
HEAT RELAY 1
W2
X
COOL
CHANGEOVER
L
VALVE
O
COMPRESSOR
CONTACTOR
Y
EM. HT. RELAY
E
T MODE SIGNAL
SYSTEM COMPONENTS
COOL CHANGEOVER
VALVE
O
DEFROST
BLOWER SPEED
RELAY
RELAY
BLOWER RELAY
G
L1
(HOT)
R
L2
DEFROST
AUX. HT. RELAY
RELAY
W2
EM. HT. RELAY
E
C
LOCKOUT
COOL
THERMOSTAT
CONTRACTOR
Y
L1
(HOT)
L2
1
M7024
1
M8382
60-2485—8