Lennox LNINVE052 Service Manual page 75

N
Replace overload
protector SAT
72
H3 or E4 is displayed
30min after power off the unit
If the overload protector SAT
is well connected?
Y
Under ambient temperature,
test the resistance of overload protector with ohmmeter;
resistance value should be＜1000ohm
Y
If the wiring terminal FA of electronic
expansion valve is well connected?
Y
Replace EKV coil of electronic expansion valve
Check the situation of refrigerant; if there is leakage,
please charge refrigerant according to the service
manual
Compressor overload protection terminal is not
connected well with the mainboard; reconnect
them correctly
Heat exchange of unit is not good (heat exchanger
is dirty and unit radiating environment is bad);
improve the radiating environment and clean the
heat exchanger
Too much load of the system causes high temperature
of compressor after working for a long time;
decrease the load for operation
N
Connect wire
N
according to wiring
diagram
Is the malfunction
eliminated?
N
Is the malfunction
eliminated?
N
Is the malfunction
eliminated?
N
Is the malfunction
eliminated?
N
Is the malfunction
eliminated?
N
Replace outdoor
mainboard AP1
End
Service Manual
Y
Y
Y
Y
Y
Installation and Maintenance