Schematic And Hookup Of T874A, D With Q674J. Used In Heat Pump Applications - Honeywell T874 Product Data

THERMOSTAT
1
FALL
H1
H1
ANTICIPATOR
4
FALL
H1
H2
6
ANTICIPATOR
8
C1
SYSTEM
RISE
SWITCH
9
C1 ANTICIPATOR
10
RISE
C2 ANTICIPATOR
C2
11
1 POWER SUPPLY. PROVIDE DISCONNECT MEANS AND OVERLOAD PROTECTION AS REQUIRED.
2
FILTER LED ON SOME MODELS.
Fig. 180. Schematic and hookup of T874A,D with Q674J. Used in heat pump applications.
SUBBASE
FAN
SWITCH
AUTO
ON
EM. HT.
LED
(RED)
2
EM. HT.
FILTER
LED
(YELLOW)
AUTO
OFF
T874 MULTISTAGE THERMOSTATS AND Q674 SUBBASES
SYSTEM COMPONENTS
R-11
R-11
W1
R-10
R-8
Y1
FAN RELAY
G
R-1
R-2
R
R-10
W2
E
X2
R-5
R-6
R-5
R-3
Y2
X1
183
FAN DELAY
RELAY
ELEC. HT.
CHANGEOVER VALVE
RELAY STG. 1
COMPRESSOR
CONTACTOR
R-6 OVERLOAD
R-6
ELEC. HT. RELAY
STG. 2
EM. HT. RELAY
T2
(HEAT PUMP
OPERATION) R-10
RANDOM START (BIOLERLESS
R-8 (OPT.)
OPERATION ) R-11
L2
L1
(HOT)
1
M5957
60-2485—8