Honeywell T874 Product Data page 175

THERMOSTAT
H1
ANTICIPATOR
C ANTICIPATOR
H1
C
FALL
H2
ANTICIPATOR
H2
FALL
1 POWER SUPPLY. PROVIDE DISCONNECT MEANS AND OVERLOAD
PROTECTION AS REQUIRED.
2 REMOVE JUMPER WHEN W1 RELAY IS USED.
3
FACTORY-INSTALLED JUMPER.
Fig. 168. Schematic and hookup of T874R with Q674L. Used in heat pump applications.
SUBBASE
FAN
SWITCH
1
AUTO
ON
2
3
SYSTEM
SWITCH
4
EM. HT.
5
HEAT
6
OFF
COOL
11
175
T874 MULTISTAGE THERMOSTATS AND Q674 SUBBASES
EM. HT.
LED (RED)
AUX. HT.
LED (GRN)
SYSTEM COMPONENTS
W3
W3 RELAY
O
COOL CHANGEOVER
VALVE
L
COMPRESSOR
MONITOR
FAN RELAY
G
L1
R
(HOT)
L2
1
W2
AUX. HT. RELAY
E
EM. HT. RELAY
X
3
HEAT
CHANGEOVER
X2
VALVE
B
W1 RELAY
W1
COMPRESSOR
2
RELAY
M5067
Y
60-2485—8