ENGLISH
Alarms for Outdoor units
Alarm
Code
Category
Type of abnormality
Main cause
2
Outdoor unit
Activation of protection device
(high pressure cut)
Activation of PSH, locked motor, abnormal operation in the power
supply phase.
Failure of fan motor, drain discharge, PCB, relay, float switch
activated.
(Pipe clogging, excessive refrigerant, innert gas mixing, fan motor
locking at cooling operation)
3
Transmission
Abnormal transmission between outdoor and
indoor units
Incorrect wiring. Loose terminals, Failure of PCB. Tripping of fuse.
Power supply OFF.
4
Abnormal transmission between inverter PCB
and RASC unit PCB
Transmission failure between inverter PCBs. (Loose Connector,
Wire Breaking, Blowout of Fuse).
5
Power supply
Reception of abnormal operation code for
detection of power source phase
Power source with abnormal wave pattern. Main power supply
phase is reversely connected or one phase is not connected.
6
Voltage
Excessively low voltage or excessively high
voltage for the inverter
Voltage drop in power supply. Incorrect wiring or insufficient
capacity of power supply wiring.
7
Cycle
Decrease in discharge gas superheat
Excessive Refrigerant Charge, Failure of Thermistor, Incorrect
Wiring, Incorrect Piping Connection, Expansion Valve Locking at
Opened Position (Disconnected Connector).
8
Excessively high discharge gas temperature at
the top of compressor
Insufficient refrigerant charge, refrigerant leakage. Expansion valve
closed or clogged.
19
Fan motor
Activation of the protection device for the indoor
fan motor
Failure of fan motor.
20
Outdoor unit
sensor
Thermistor for discharge gas temperature
(THM9)
Incorrect wiring, disconnected wiring, broken cable, short circuit.
21
High pressure sensor
22
Thermistor for outdoor ambient temperature
(THM7)
24
Thermistor for evaporating temperature (THM8)
Incorrect Wiring, Disconnected Wiring, Wire Breaking, Short
Circuit, Fan Motor Locking at Heating Operation.
31
System
Incorrect capacity setting or combined capacity
between outdoor and indoor units
Incorrect Capacity Code Setting, Excessive or Insufficient Indoor
Unit Total Capacity Code.
35
Incorrect indoor unit number setting
Duplication of indoor unit number, number of indoor units over
specifications.
36
Incorrect of Indoor Unit Combination.
38
Abnormality of picking up circuit for protection
(Outdoor unit)
Failure of indoor unit PCB, incorrect wiring, connection to PCB in
indoor unit.
45
Protection
device
Activation of the safety device from excessively
high discharge pressure
Overload (obstruction of HEX, short circuit) mixture of inert gas,
Excessive Refrigerant.
47
Activation of the safety device from excessively
low suction pressure (protection from vacuum
operation)
Shortage or leakage of refrigerant, piping clogging, expansion
valve close-locked, fan motor locked.
48
Activation of overcurrent protection
Overload, overcurrent. Failure of Inverter PCB, heat exchanger
clogged, locked compressor. EVI/EVO failure.
51
Inverter
Abnormal operation of the current sensor
Incorrect wiring of current sensor. Failure of control PCB or Inverter
PCB.
53
Inverter fin temperature increase
Inverter module (IPM, DIP-IPM) and Inverter PCB abnormality.
Failure of compressor, clogging of heat exchanger.
54
Abnormality of inverter fin temperature
Heat Exchanger Clogging. Fan Motor Failure.
55
Abnormality of inverter module
Failure of DIP-IPM, IPM or Inverter PCB.
57
Outdoor
Activating the protection of the fan motor
5B
Outdoor fan
Activation of over current protection
TROUBLESHOOTING
PMML0575 rev.1 - 09/2021
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