Service Manual

8. Troubleshooting
241
SMGB0079 rev.0 - 01/2013
8
Is expansion valve of I.U.
open-locked in cooling operation?
Is expansion valve of O.U.
open-locked in heating operation?
Is the supply voltage
AC220/240V+10%?
Is voltage higher
than 170V during
operation?
Is refrigerant
overcharged?
Is the discharge
pressure high?
Restart operation.
Normal
Yes It trips.
No
Yes
Compressor
stops after
few minutes.
(Itc=1)
(Itc=21)*
Compressor
stops
immediately.
(Itc=1, 12)*
Check the compressor.
Replace it if faulty.
Check the capacity
and wiring of
the power source.
Faulty Inverter PCB
Replace it.
Check stop valve
and expansion valve.
Check clogging of
the heat exchanger.
Check fan motor.
Replace
expansion valve.
Charge refrigerant
correctly.
No
No
Restart operation
after main switch ON.
Check
the compressor.
No
No
No
No
Is voltage higher
than 170V at
any time?
Is crankcase
heater ON?
Yes
No
Is the compressor
running current
as same as
operating current?
Yes
Yes
No
Yes
Yes
Yes
Yes
O.U.: Outdoor Unit
I.U.: Indoor Unit
Yes
Is heat exchanger
clogged?
Remove clogging or
Replace heat exchanger.
No
Turn OFF power,
disconnect U, V, W
from compressor
terminals and restart.
Does the protecting
function activate? *3)
Abnormal
Failure of Inverter PCB.
Replace it.
Check
the compressor.
* Refer to the item 1.2.8 (D)
“Cause Code of Inverter Stoppage” for details.
N O T E
• *1)PerformthehighvoltagedischargeworkbyreferringtotheitemProcedureofcheckingothermainparts, 
beforecheckingandreplacingtheinvertercomponents.
• *2) Regarding replacingorchecking method forinvertercomponents, refer toitem Procedure of checking
othermainparts.
• *3)TurnONtheNo.1switchofthedipswitchDSW1onPCB2(inverter)whenrestartingwithdisconnectingthe
terminalsofthecompressor.Aftertroubleshooting,turnOFFtheNo.1switchofthedipswitchDSW1onPCB2.
• Whenthealarmcode“53”isindicated,theoutdoorfanmotor(DCmotor)ensurethatDCfanmotorischecked
accordingtotheitemProcedureofcheckingothermainparts.