Schematic And Hookup Of T874L With Q674B. Used In Heat Pump Applications - Honeywell T874 Product Data

T874 MULTISTAGE THERMOSTATS AND Q674 SUBBASES
THERMOSTAT
H1
H1 ANTICIPATOR
FALL
H2
H2 ANTICIPATOR
FALL
C1
RISE
C1 ANTICIPATOR
1 POWER SUPPLY. PROVIDE DISCONNECT MEANS AND OVERLOAD
PROTECTION AS REQUIRED.
Fig. 215. Schematic and hookup of T874L with Q674B. Used in heat pump applications.
60-2485—8
SUBBASE
1
2
SYSTEM
SWITCH
HEAT
3
OFF
4
COOL
5
7
FAN
SWITCH
8
LO
MED
9
HIGH
10
ON
11
12
202
SYSTEM COMPONENTS
RELAY 1
N.O. 2
H1
COMPRESSOR
CONTACTOR
Y
R
C
FIELD
REMOVABLE
JUMPER
H2
L
CHECK
R1 RELAY N.C. 1
LED (RED)
R2
RELAY
N.O. 1
O
K1 RELAY
G1
G2
L1
(HOT)
L2
1
S1
RELAY
S1
RELAY N.C.
AUX. HT. RELAY
COMPRESSOR
CONTACTOR
COOL
CHANGEOVER
VALVE
R1 RELAY
K2 RELAY
M2993