T874 MULTISTAGE THERMOSTATS AND Q674 SUBBASES
197 60-24858
Fig. 207. Schematic and hookup of T874J with Q674L. Used in heat pump applications. Fig. 208. Schematic and hookup of T874D with Q674D. Used in standard applications.
H1
FALL Y
G
R
E
L
W2
FAN RELAY
COMPRESSOR
CONTACTOR
OFF
COOL
SYSTEM
SWITCH
H1 ANTICIPATOR
C1 ANTICIPATOR
AUTO
ON
FAN SWITCH
1POWER SUPPLY. PROVIDE DISCONNECT MEANS AND OVERLOAD
PROTECTION AS REQUIRED.
M2985
THERMOSTAT SUBBASE SYSTEM COMPONENTS
COOL CHANGEOVER
VALVE
O.D.T.
4
6
8
9
10
H2
FALL
RISE CO
L1
(HOT)
L2
1
H2
ANTICIPATOR
SUPL. HT.
LED (RED)
O
H.C.R.1
H.C.R.1
H.C.R.2
H.C.R.2
H.C.R.3
C
2
3
5
11
12
C1 CO
SUPL. HT.
RISE
HEAT
H1
FALL
W1
W2
HEAT RELAY 1
H1 ANTICIPATOR
C1 ANTICIPATOR 1POWER SUPPLY. PROVIDE DISCONNECT MEANS AND OVERLOAD PROTECTION AS REQUIRED.
RC-RH REMOVABLE JUMPER WHEN SPECIFIED. M2986
THERMOSTAT SUBBASE SYSTEM COMPONENTS
COMPRESSOR
CONTACTOR 2
COMPRESSOR
CONTACTOR 1
1
5
6
8
9
10
11
H2
FALL
C2 ANTICIPATOR
RISE
RISE
C1
C2
Y1
Y2
HEAT RELAY 2
L1
(HOT)
L2
1
H2
ANTICIPATOR
L1
(HOT)
L2
1
RC
RH
2
4
NO
FAN
SWITCH
NO
SYSTEM
SWITCH
2