59
Installation and Maintenance
Service Manual
4. Start-up failure (LC) (AP1 below means control board of outdoor unit)
Main detection points:
● 
If the compressor wiring is correct?
● 
If the stop time of compressor is sufcient?
● 
If the compressor is damaged?
● 
If the refrigerant charging amount is too much?
If the stop time of compressor 
       is more than 3min?
The stop time is not sufficient and 
the high and low pressure of system 
is not balanced , please start the unit 
after 3min
         If the compressor wire 
COMP(UVW) is well connected and 
   connection sequence is correct?
Check the connection situation 
of outdoor mainboard AP1 and 
compressor COMP, and the 
connect it according to wiring 
diagram
If the refrigerant charging 
 amount is too much?
Does the unit 
start up normally?
Charge the refrigerant 
according to service 
manual
Does the unit 
start up normally?
Replace outdoor 
mainboard AP1
Is the malfunction 
   eliminated?
Replace the 
compressor
End
Turn on the unit