
10 Troubleshooting
Troubleshooting procedure
SMGB0091 rev.2 - 11/2015
197
10
10.2.2 Alarm codes
•
The RUN LED flickers and “ALARM” is displayed on the remote control switch.
• The unit number, the alarm code and the unit code are alternately displayed on the set temperature section.
• The unit number and the alarm code are displayed on the 7 segments of the RASC unit PCB and Remote control
Screen (if installed).
Code
number
Category
Type of abnormality
Main cause
1
Indoor unit
Activation of protection device (float switch)
Failure of fan motor, drain discharge, PCB, relay,
float switch activated (High Water Level in Drain Pan,
Abnormality of Drain Pipe, Float Switch or Drain Pan).
2
Protection
device
Activation of protection device
Activation of the float switch (FS).
Activation of the internal thermostat protection of the
motor (ITO).
Activation of the high pressure switch (PSH).
Variable frequency driver failure (VFD).
3
Transmission
Abnormal transmission between RASC 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) or faulty RASC fan motor.
8
Excessively high discharge gas temperature at
the top of compressor
Insufficient refrigerant charge, refrigerant leakage.
Expansion valve closed or clogged.
11
Indoor unit
sensor
Air inlet thermistor
Failure of thermistor, sensor, connection. (Incorrect
Wiring, Disconnected Wiring, Wire Breaking, Short
Circuit).
12
Air outlet thermistor
13
Freeze protection thermistor
14
Gas piping thermistor
15
Econofresh
Thermistor of fresh outdoor air
16
Indoor unit
sensor
Remote thermistor
17
Thermistor of remote control switch
19
Fan motor
Activation of the protection device for the
indoor fan motor
Failure of fan motor.
20
RASC 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)
31
System
Incorrect capacity setting or combined capacity
between RASC 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.
"Indoor Unit is Designed for Other Refrigerant (R22
or R407C)".
38
Abnormality of picking up circuit for protection
(RASC unit)
Failure of indoor unit PCB, incorrect wiring, connection
to PCB in indoor unit.