Nobu NBL4-18IDU32 Service Manual page 52

Outdoot Unit
(1) Malfunction of Desynchronizing of Compressor (H7)
Main check point:
Whether the system pressure is too high?
Whether the electronic expansion valve can work normally?
Whether the radiation for the unit is in good condition?
Malfunction diagnosis process:
66 48
Desynchronizing malfunction
occurs after de-energizing
and turning on the unit
Yes
Whether stop time for
compressor is more than 3min?
Yes
Whether valve of outdoor unit is
opened?
Yes
Whether wire connection for
compressor is correct?
Yes
Whether electronic expansion
valve is damaged?
Yes
Replace main board of
outdoor unit
Is malfunction eliminated?
No
Replace compressor
End
No
No
Open the valve
No
Is malfunction eliminated?
No
Connect wire correctly
No
Is malfunction eliminated?
No
Replace electronic
expansion valve
No
Is malfunction eliminated?
Yes
Service Manual
Service Manual
Yes
Yes
Yes
Installation and Maintenance
Installation and Maintenance