Honeywell T874 Product Data page 180

T874 MULTISTAGE THERMOSTATS AND Q674 SUBBASES
THERMOSTAT
H1 ANTICIPATOR
FALL
H2
ANTICIPATOR
FALL
C1 ANTICIPATOR
CO
RISE
10
C1
RISE
1
Fig. 175. Schematic and hookup of T874G with Q674J. Used in heat pump applications.
THERMOSTAT
FALL
H1
FALL
SETBACK
2
RISE
CO
RISE C1 ANTICIPATOR
C1
1
POWER SUPPLY. PROVIDE DISCONNECT MEANS AND OVERLOAD PROTECTION AS REQUIRED.
2 SETBACK STAGE OFFSET 12°F (7°C) FROM H1 STAGE.
LEDS ON SOME MODELS.
3
Fig. 176. Schematic and hookup of T874G with Q674C. Used in standard applications.
60-2485—8
1
FAN
SWITCH
2
AUTO
4
6
8
SYSTEM
SWITCH
SUPL. HT.
9
OFF
POWER SUPPLY. PROVIDE DISCONNECT MEANS AND OVERLOAD
PROTECTION AS REQUIRED.
2
H1 ANTICIPATOR
3
4
AUTO
6
SYSTEM
SWITCH
8
AUTO
9
10
SUBBASE
ON
ON
AUTO
(YEL)
HEAT PUMP
(GRN)
SUBBASE
ON
FAN SWITCH
OFF
180
SYSTEM COMPONENTS
O
COOL
FAN RELAY
CHANGEOVER VALVE
G
R
O.D.T.
W2
H.C.R. 1
H.C.R. 2
E
L
MANUAL
(RED)
C
Y
DEFROST
(RED)
D
SYSTEM COMPONENTS
Y1
COOL
CHANGEOVER VALVE
Y2
COMPRESSOR
CONTACTOR
G
FAN RELAY
OPEN-NIGHT
CLOSED-DAY
R
SETBACK RELAY
L
X1
LED
C
3
LED
X2
M5730
L1
(HOT)
L2 1
H.C.R. 1
H.C.R.2
H.C.R.3
COMPRESSOR
CONTACTOR
M2112A
L2
1
L1
(HOT)