Honeywell T874 Product Data page 163

THERMOSTAT
FALL
H1
H1 ANTICIPATOR
FALL
H2 ANTICIPATOR
H2
RISE
C1
RISE
C1 ANTICIPATOR
C2
C2 ANTICIPATOR
1
POWER SUPPLY. PROVIDE DISCONNECT MEANS AND OVERLOAD PROTECTION AS REQUIRED.
2
FACTORY SUPPLIED FIELD INSTALLED JUMPER TO E-X2 FOR CONSTANT POWER TO EM HT LIGHT IN EM HT POSITION.
3
OPTIONAL FIELDWARE JUMPER TO ALLOW SINGLE SYSTEM TRANSFORMER.
Fig. 152. Schematic and hookup of T874D with Q674F. Used in standard applications.
THERMOSTAT
H1
ANTICIPATOR
H1
FALL
FALL
H2 ANTICIPATOR
H2
C1 RISE
CO
RISE
C1 ANTICIPATOR
1
POWER SUPPLY. PROVIDE DISCONNECT MEANS AND OVERLOAD PROTECTION AS REQUIRED.
Fig. 153. Schematic and hookup of T874G with Q674F. Used in heat pump applications.
T874 MULTISTAGE THERMOSTATS AND Q674 SUBBASES
SUBBASE
1
FAN SWITCH
AUTO
ON
4
6
SYSTEM
SWITCH
OFF
8
EM. HT.
HEAT
9
AUTO
10
COOL
11
SUBBASE
1
AUTO
2
ON
FAN
SWITCH
4
6
SYSTEM
SWITCH
OFF
8
EM. HT.
HEAT
AUTO
9
COOL
10
163
SYSTEM COMPONENTS
HEAT RELAY
W1
COMPRESSOR
CONTRACTOR 1
Y1
FAN RELAY
G
RC
HEAT RELAY 2
3
W2
RH
EM. HT. RELAY
E
B
2
X2
EM. HEAT
LED (RED)
X1
COMPRESSOR
O
CONTRACTOR 2
Y2
SYSTEM COMPONENTS
COOL CHANGEOVER
VALVE
O
G
R
OUTDOOR
THERMOSTAT
W2
E
AUX. HT. RELAY
CONTACT
EM. HT. LED
(RED)
X
Y
COMPRESSOR
CONTACTOR
L1 L2
1
(HOT)
1
L1 L2
(HOT)
M8377
FAN RELAY
L1
(HOT)
L2
1
AUX. HT. RELAY
EM. HT.
RELAY
M8381
60-2485—8