Schematic And Hookup Of T874C, R With Q674L. Used In Heat Pump Applications - Honeywell T874 Product Data

THERMOSTAT
RESET
1
2
H1
ANTICIPATOR
3
H1
FALL
4
5
H2
FALL
6
H2
ANTICIPATOR
7
8
C1
ANTICIPATOR
C1
RISE
10
1 POWER SUPPLY. PROVIDE DISCONNECT MEANS
AND OVERLOAD PROTECTION AS REQUIRED.
2 REMOVE FACTORY INSTALLED V-VR JUMPER WHEN
CONNECTING A TWO TRANSFORMER SYSTEM.
Fig. 110. Schematic and hookup of T87C,R with Q674L. Used in heat pump applications.
T874 MULTISTAGE THERMOSTATS AND Q674 SUBBASES
SUBBASE
FAN SWITCH
AUTO
ON
SERVICE
LED (RED)
SYSTEM
SWITCH
EM. HT.
HEAT
OFF
COOL
3 REMOVE FACTORY-INSTALLED S-Y JUMPER TO DISABLE SERVICE LIGHT.
131
SYSTEM COMPONENTS
V
2
VR
INTERNAL
COMPRESSOR
CONTACTOR THERMOSTAT
M
OVERLOAD
FAN
SWITCH
RELAY
F
SERVICE
L
OUTDOOR
THERMOSTAT
S
EM. HT. RELAY
3
CONTACT
Y
E
EM. HT.
LED (YELLOW)
X
C815A OUTDOOR
THERMISTOR
A
COOL CHANGEOVER
VALVE
R
L1
(HOT)
L2
1
HI PRESSURE
SWITCH
SUPL. ELEC.
HT. RELAY
TIME DELAY
FAN RELAY
ELEC. HT. RELAY
M2854
60-2485—8