Honeywell T874 - Page 201

T874 MULTISTAGE THERMOSTATS AND Q674 SUBBASES
201 60-2485—8
Fig. 214. Schematic and hookup of T874A with Q674B. Used in standard applications.
H1
R
L
COMPRESSOR
CONTACTOR
HIGH
ON
SYSTEM
SWITCH
COOL
OFF
FAN
SWITCH
1
POWER SUPPLY. PROVIDE DISCONNECT MEANS AND OVERLOAD
PROTECTION AS REQUIRED.
M2992
THERMOSTAT
SUBBASE
SYSTEM COMPONENTS
COOL
CHANGEOVER
VALVE
4
1
L1
(HOT
)
L2
1
CHECK
LED (RED)
O
2
3
5
LO
MED
AUX. HT. RELAY
R1 RELAY
K1 RELAY
G1
K2 RELAY
G2
R2
RELAY
N.O. 1
HEAT
C
Y
COMPRESSOR
CONTACTOR
H1
FALL
H1 ANTICIPATOR
C1 ANTICIPATOR
C1
RISE
S1 RELAY N.C.
11
12