Schematic And Hookup Of T874H With Q674C. Used In Standard Applications; Schematic And Hookup Of T874L With Q674C. Used In Heat Pump Applications - Honeywell T874 Product Data

T874 MULTISTAGE THERMOSTATS AND Q674 SUBBASES
THERMOSTAT
FALL
RISE
CO
RISE
Fig. 164. Schematic and hookup of T874H with Q674C. Used in standard applications.
THERMOSTAT
FALL
H1
3
H1 ANTICIPATOR
H2 ANTICIPATOR
H2
FALL
3
C1
C1
ANTICIPATOR
RISE
1
POWER SUPPLY. PROVIDE DISCONNECT MEANS
AND OVERLOAD PROTECTION AS REQUIRED.
Fig. 165. Schematic and hookup of T874L with Q674C. Used in heat pump applications.
60-2485—8
H1
ANTICIPATOR
2
3
FAN SWITCH
H1
AUTO
4
ON
6
SYSTEM SWITCH
8
OFF
9
C1 AUTO
ANTICIPATOR
10
1 POWER SUPPLY. PROVIDE DISCONNECT MEANS
C1
AND OVERLOAD PROTECTION AS REQUIRED.
2 R-L JUMPER SUPPLIED BY HONEYWELL.
1
2
3
FAN
SWITCH
4
5
7
SYSTEM
8
SWITCH
9
10
SUBBASE
MALFUNCTION
LED (RED)
SUBBASE
AUTO
ON
OFF
AUTO
2
FIELD REMOVABLE JUMPER.
3 H1 AND C1 ARE DPST SWITCHES.
172
SYSTEM COMPONENTS
L1
(HOT)
1
L2
O
COOL CHANGEOVER
VALVE
Y
COMPRESSOR
CONTACTOR
G
R
FAN RELAY
2
L
HEAT CHANGEOVER
VALVE
B
X
MALFUNCTION
SWITCH
M5726
SYSTEM COMPONENTS
J
R1 N.O.2
S
SOLENOID RELAY
2
G
FAN RELAY
R
C
H2
AUX. HT. RELAY
R1 N.C.1
H1
R2 N.O. 1
O
L1
(HOT)
1
L2
S1 RELAY
S1 N.C.
COMPRESSOR
CONTACTOR
REV. VALVE
R1 RELAY
M5727