Honeywell T874 - Page 212

T874 MULTISTAGE THERMOSTATS AND Q674 SUBBASES
60-2485—8 212
Fig. 228. Schematic and hookup of T874R with Q674L. Used in heat pump applications.
H1
FALL
C1
L1
(HOT)
L2
1
1
2
2
POWER SUPPLY. PROVIDE DISCONNECT MEANS AND OVERLOAD PROTECTION AS REQUIRED.
REMOVABLE JUMPER (INSTALLED).
THERMOSTAT
SUBBASE
SYSTEM COMPONENTS
H2
FALL
H1/C1 ANTICIPATOR
H2 ANTICIPATOR
RESET
EM. HT.
HEAT
OFF
COOL
AUX. HT.
LED
(GREEN)
EM. HT.
LED (YELLOW)
C815A OUTDOOR
THERMISTOR
COOL CHANGEOVE
R
VALVE
ELECTRIC
HEAT RELAY
ELECTRIC
HEAT RELAY
EM. HT.
O.D.S.
SERVICE
EM. HT. RELAY
FAN RELAY
COMP. RELAY O.L. IN. STAT. HI. PRO.
AUTO
ON
M325
9
1
2
3
4
5
6
11
12
O
T
C
E
W1
L
G
Y1
R
SENSOR
LED (RED)
SYSTEM
SWITCH
FAN
SWITCH