Filter
Top Products
T874 MULTISTAGE THERMOSTATS AND Q674 SUBBASES
60-2485—8222
Fig. 247. Schematic and hookup of T874W with Q674L. Used in heat pump applications.
1
T
W3
G
R
E
X1
C
B
O
X2
Y1
Y2
C815A OUTDOOR
THERMISTOR
AUX. HT. RELAY
FAN RELAY
EM. HT. RELAY
CHANGEOVER
RELAY (HEAT)
CHANGEOVER
RELAY (COOL)
COMPRESSOR
CONTACTOR 1
COMPRESSOR
CONTACTOR 2
EM.HT.
AUTO
ON
FAN SWITCH
H1 ANTICIPATOR
H2 ANTICIPATOR
H3 ANTICIPATOR
RESET
FALL
FALL
FALL
H1
H3
H2
AUX. HEAT
LED (GREEN)
POWER SUPPLY. PROVIDE DISCONNECT MEANS AND OVERLOAD PROTECTION AS REQUIRED.
CONNECT CHANGEOVER RELAY TO 'O' TERMINAL FOR CHANGEOVER IN COOLING OR TO 'B' TERMINAL FOR CHANGEOVER IN HEATING.
M6999
C1 ANTICIPATOR
RISE
RISE
C2 ANTICIPATOR
C1
C2
EM. HEAT
LED (RED)
CHECK LED
(YELLOW)
HEAT
OFF
COOL
SYSTEM
SWITCH
2
2
THERMOSTAT
SUBBASE
SYSTEM COMPONENTS
1
2
3
4
5
6
8
9
10
11
12
L1
(HOT)
L2
1