Schematic And Hookup Of T874W With Q674C. Used In Standard Applications; Schematic And Hookup Of T874R With Q674L. Used In Heat Pump Applications - Honeywell T874 Product Data

THERMOSTAT
H1 ANTICIPATOR
3
FALL
H1
FALL
H3
4
H2 ANTICIPATOR
FALL
C2
H2
ANTICIPATOR
3
C1
RISE
C2
RISE
C2 ANTICIPATOR
5
THERMISTER
1 POWER SUPPLY. PROVIDE DISCONNECT MEANS AND
OVERLOAD PROTECTION AS REQUIRED.
2
MOMENTARY POSITION. SPRING RETURN TO "ON" UPON SWITCH RELEASE.
3 H1 AND C1 ARE DPST SWITCHES.
Fig. 100. Schematic and hookup of T874W with Q674C. Used in standard applications.
THERMOSTAT
H1/C1
H1
ANTICIPATOR
C1
FALL
H2
H2
ANTICIPATOR
FALL
1 POWER SUPPLY. PROVIDE
DISCONNECT MEANS AND
OVERLOAD PROTECTION
AS REQUIRED.
Fig. 101. Schematic and hookup of T874R with Q674L. Used in heat pump applications.
SUBBASE
1
2
OFF
4
AUTO
5
6
FAN
SWITCH
AUTO
7
ON
8
2
9
10
11
12
SUBBASE
2
AUTO
ON
FAN SWITCH
3
4
5
SYSTEM
SWITCH
6
EM. HT.
HEAT
OFF
COOL
125
T874 MULTISTAGE THERMOSTATS AND Q674 SUBBASES
W1
SYSTEM
SWITCH
W2
HEAT RELAY 3
W3
Y2
SERVICE
LED (RED)
A
G
R
O
COMPRESSOR RELAY
Y1
T
T
4
H3 OFFSET 12 F FROM H2 FOR NIGHT SETBACK.
5 THERMISTOR INTERNAL TO THERMOSTAT.
SYSTEM COMPONENTS
COOL CHANGEOVER
VALVE
O
G
FAN RELAY
R
W
AUX. HT. RELAY
X
EM. HT.
LED (RED)
B
COMPRESSOR
CONTACTOR
Y
SYSTEM COMPONENTS
HEAT RELAY 1
HEAT RELAY 2
COMPRESSOR
CONTACTOR 2
L2
FAN RELAY
L1
(HOT)
1
MOMENTARY
CIRCUIT
EXTERNAL
TEMP.
READOUT
M532
L1
(HOT)
L2
1
M3718A
60-2485—8