T874 MULTISTAGE THERMOSTATS AND Q674 SUBBASES
60-2485818
Fig. 20. Tracing the heat 1 anticipation circuit.Fig. 21. Tracing the heat 2, anticipation and AUX. HT. LED circuit.
M5842
L1
(HOT)
L2
1
LACO CHP
Y
B
E
O
G
L
X
W2
W3
RODT 1
RTD 1 EHR 1 RTD 2
ODT 2
EHR 2 RTD 3
RD
SYSTEM
MONITOR
FAN RELAY
COMPRESSOR
CONTACTOR
CHANGEOVER
VALVE
EM. HT.
RELAY
RTD 1
AUX. HT.
LED
(GREEN)
EM. HT.
LED (RED)
FAN SWITCH
ON
AUTO
SYSTEM
SWITCH
EM. HT.
HEAT
OFF
COOL
H2
FALL
H1
FALL
C1
2
3
4
5
6
H1/ C1
ANTICIPATOR
H2
ANTICIPATOR
1POWER SUPPLY. PROVIDE
DISCONNECT MEANS AND
OVERLOAD PROTECTION
AS REQUIRED.
THERMOSTAT SUBBASE SYSTEM COMPONENTS
M5843
L1
(HOT)
L2 1
LACO CHP
Y
B
E
O
G
L
X
W2
W3
RODT 1
RTD 1 EHR 1 RTD 2
ODT 2
EHR 2 RTD 3
RD
SYSTEM
MONITOR
FAN RELAY
COMPRESSOR
CONTACTOR
CHANGEOVER
VALVE
EM. HT.
RELAY
RTD 1
AUX. HT.
LED
(GREEN)
EM. HT.
LED (RED)
FAN SWITCH
ON
AUTO
SYSTEM
SWITCH
EM. HT.
HEAT
OFF
COOL
H2
FALL
H1
FALL
C1
2
3
4
5
6
H1/C1
ANTICIPATOR
H2
ANTICIPATOR
1POWER SUPPLY. PROVIDE
DISCONNECT MEANS AND
OVERLOAD PROTECTION
AS REQUIRED.
THERMOSTAT SUBBASE SYSTEM COMPONENTS