53
Duct Type Split Air Conditioner
Service Manual
2.2 Low Pressure Protection
Compressor Low Pressure
Protection
Check if the swing blades of the indoor unit 
are fully open?
Check if the fans for the indoor and outdoor 
units are working?
Check if the ventilation of the heat 
exchangers for the indoor and outdoor units 
works properly?
Check if the panel of the outdoor unit has 
been sealed?
Check if the gas and liquid valves of the 
outdoor unit are fully open?
Check if the operational modes of the indoor 
unit have been set correctly? 
Check if the refrigeration capacity 
of the system is too low?
Check if the filter and heat exchange fins of 
the outdoor  unit are dirty or clogged?
Check if the capacity output of the outdoor 
unit meets with the required capacity of the 
indoor unit?
Yes
No
Yes
Yes
Yes
Yes
Yes
No
Clear any obstacle
Cover the panel
Fully open the valve
refer to mode conflict
refer to capacity code
Check the swing motor and 
the signal input
Check the fan motor 
and the signal input
Yes
No
No
No
No
No
Yes
No
the system pipe is clogged
refer to maintenance
No
Yes
Add refrigerant by referring to the refrigerant 
volume specified on the nameplate and the 
refrigerant volume calculated on Page?