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1-39
TROUBLESHOOTING
“RUN” light flickers and “ALARM” is indicated on the remote control switch.
The unit No., alarm code and the unit code is alternately indicated on the set temperature section,
and the unit No. and alarm code are indicated on the display of the outdoor unit PCB.
In the case that the discharge gas superheat less than 15 deg. at the top of the compressor is
maintained for 30 minutes, retry operation is performed. However, when the alarm occurs again
within 90 minutes, this alarm code is indicated.
Alarm
Code
Decrease of Discharge Gas Superheat
Is the thermistor on
top of compressor
good? *1)
Is superheat value
under 15 degrees
o
C?
Yes
Check the high-pressure
and compressor discharge
gas temperature and
calculate superheat value
by outdoor unit PCB.
Eliminate rapid
change of heat
load in a room or
short path of
discharged air
among outdoor
units.
Remove sudden
changes of load
like short path of
outgoing air to the
air intake of the
outdoor unit, or the
cause of frequent
thermo-ON/OFF.
Faulty Thermistor
No
No
No
Is the thermistor
installed correctly
on the compressor?
Yes
Install it correctly.
No
Is it at cooling or
heating mode when the
alarm has occurred?
Is the opening
degree of ex. valve
of outdoor bypass
below 5%?
Is the connector
(CN12) for ex. valve
of outdoor bypass
connected properly?
Is the connector on
indoor unit PCB for
ex. valve connected
properly?
Are the refrigerant
piping and electric
wiring matching?
Is refrigerant
correctly charged?
Is gas leaking?
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Superheat: under
15 degrees
o
C?
Cooling
Check the discharge
pressure and compressor
discharge gas temperature
and calculate superheat
value by outdoor unit PCB.
Heating Operation
Cooling Operation
Heating
No
Plug the connectors
(*2) of PCB1
properly.
No
Charge correct
refrigerant volume.
Refer to TCII.
No
Check the ex.
valve.
No
Plug the connector
CN12 of PCB1
properly.
No
No
No
Match the
refrigerant piping
and electric wiring.
Plug the
connector properly.
Repair leaks of gas.
Correctly charge
refrigerant.
No
Is the opening of the
outdoor unit heat
exchanger's expansion
valve under 12%?
<FX Series Only>
Are the connectors
(*2) of PCB1 of the
outdoor unit heat
exchanger's electric
expansion valve
connected properly?
Yes
5 to 20HP
24 and 30HP
CN10 and CN11
CN10, CN11, CN12
and CN20
*2): PCB1 Connector No.
is shown in the right
table.
*1): Refer to "Characteristics of Thermistor" of page 1-53.
Position of Thermistor
THM8(Td1)
for Inverter Drive
RAS-5FSG, RAS-5FS3
THM8(Td1)
for Inverter
Drive
RAS-8FSG, RAS-8FS3
RAS-10FSG, RAS-10FS3
RAS-8FXG, RAS-8FX3
RAS-10FXG, RAS-10FX3
THM9(Td2)
for Constant
Speed Drive
THM8(Td1)
for Inverter
Drive
RAS-16FSG, RAS-16FS3
THM9(Td2)
RAS-20FSG,
RAS-20FS3
RAS-24FSG1,
RAS-24FS5,
RAS-30FSG1,
RAS-30FS5
THM12(Td3)
THM13(Td4)
20,24,30HP
only
for Constant Speed Drive