Honeywell T874 Product Data page 140

T874 MULTISTAGE THERMOSTATS AND Q674 SUBBASES
THERMOSTAT
H1
C1
FALL
H2
FALL
1
POWER SUPPLY. PROVIDE DISCONNECT MEANS AND OVERLOAD PROTECTION AS REQUIRED.
Fig. 119. Schematic and hookup of T874R with Q674L. Used in heat pump applications.
THERMOSTAT
FALL
H1
C1
FALL
H2
1 POWER SUPPLY. PROVIDE DISCONNECT MEANS AND OVERLOAD PROTECTION AS REQUIRED.
Fig. 120. Schematic and hookup of T874R with Q674L. Used in heat pump applications.
60-2485—8
RESET
HEATER
1
H2 ANTICIPATOR
2
FAN SWITCH
3
4
SYSTEM
SWITCH
5
C1
ANTICIPATOR
6
11
12
H1 ANTICIPATOR
2
FAN SWITCH
H1/C1
ANTICIPATOR
3
4
5
6
H2
ANTICIPATOR
11
RESET HEATER
12
SUBBASE
AUTO
ON
EM. HT.
HEAT
OFF
COOL
SUBBASE
AUTO
ON
EM. HT.
LED (RED)
SYSTEM
SWITCH
EM. HT.
HEAT
OFF
COOL
140
SYSTEM COMPONENTS
(HOT)
1
C815A
OUTDOOR
THERMISTOR
T
W2
AUX. HT. RELAY
G
FAN RELAY
R
X
SERVICE LED
(YELLOW) SERVICE
Z
EM. HT.
LED (RED) EM. HT. RELAY
K
COMPRESSOR
CONTACTOR
Y
W1
HEAT CHANGEOVER
RELAY
SYSTEM COMPONENTS
(HOT)
1
FAN RELAY
G
R
AUX. HT. RELAY
W
H
"H" RELAY
B
X
EM. HT. RELAY
T
C815A1039
THERMISTOR
O
CHANGEOVER VALVE (COOL)
Y
COMPRESSOR
CONTACTOR
L1 L2
M5955
L1 L2
M3173B