SiENBE28-901
Troubleshooting
Air Cooled Refrigeration Condensing Unit
137
[Check 8] List of Malfunction Codes Related to Inverter
Code
Name
Condition for determining malfunction
Major faulty point
Compressor current
L5
INV Compressor
Instantaneous Overcurrent
Inverter output causes an overcurrent
to flow even instantaneously.
Inverter getting caught in liquid
Faulty compressor
Faulty inverter PCB
L8
Overcurrent of INV
compressor (electronic
thermal)
The compressor performs overload
operation.
Loss of synchronization is detected.
Liquid back of compressor
Sharp change in load
Disconnection of compressor wiring
Faulty inverter PCB
Protecti
on devi
ce, etc.
L1
Faulty Inverter PCB
No output is produced.
Faulty heavy current part of inverter
L9
Faulty INV Compressor
Startup
The compressor motor fails to start
up.
Inverter getting caught in liquid or
faulty compressor
Excessive oil or refrigerant
Faulty inverter PCB
E5
Inverter Compressor Lock
The compressor is in locked state
(does not rotate).
Faulty compressor
L4
Rise in Radiation Fin
Temperature
The radiation fin temperature
exceeds the reference value (while in
operation).
Malfunction of fan
Long-term overload operation
Faulty inverter PCB
U2
Abnormal Power Supply
Voltage
The inverter power supply voltage is
high or low.
Abnormal power supply
Faulty inverter PCB
P1
Power Supply Imbalance
The three-phase power supply has a
significant voltage imbalance.
Abnormal power supply (Power
supply imbalance of not less than 2%)
Faulty inverter PCB
End of PCB service life
LC
Malfunction Related to
Transmission (between
Main PCB and Control
PCB)
The outdoor unit PCB cannot make
communications among the control
PCB, inverter PCB, and fan PCB.
Broken wire in communication line
Faulty control PCB
Faulty inverter PCB
Faulty fan PCB
P4
Faulty fin thermistor
The fin thermistor gets short-circuited
or open.
Faulty fin thermistor