38
UP
(4210)
Compressor overcurrent interruption
AbnormalifovercurrentDCbusorcom-
pressorisdetectedaftercompressorstarts
operatingfor30seconds.
1Stopvalveofoutdoorunitis
closed.
2Decreaseofpowersupply
voltage
3Looseness,disconnectionor
converseofcompressorwiring
connection
4Defectivefanofindoor/outdoor
units
5Shortcycleofindoor/outdoor
units
6Defectiveinputcircuitofoutdoor
controllerboard
7Defectivecompressor
1Openstopvalve.
2Checkfacilityofpowersupply.
3Correctthewiring(U·V·Wphase)to
compressor.Referto"10-9.TESTPOINT
DIAGRAM"(Outdoorpowercircuitboard).
4Checkindoor/outdoorfan.
5Solveshortcycle.
6Replaceoutdoorcontrollercircuitboard.
7Checkcompressor.
Referto"10-6.HOWTOCHECKTHE
PARTS".
Note:Beforethereplacementoftheoutdoor
controllercircuitboard,disconnectthe
wiringtocompressorfromtheoutdoor
powercircuitboardandchecktheoutput
voltageamongphases,U,V,W,during
testrun.Nodefectonboardifvoltage
amongphases(U-V,V-WandW-U)is
same.Makesuretoperformthevoltage
checkwithsameperformingfrequency.
Abnormal point and detection method Case Judgment and action
Check Code
20
PFC/IGBT error
(Undervoltage)
•Whencompressorisrunning,
DCbusvoltagestaysat310V
orlowerforconsecutive10
seconds
1Incorrectswitchsettingsonthe
outdoorcontrollercircuitboard
formodelselect
2Defectiveoutdoorpowercircuit
board
3Defectiveoutdoorcontroller
circuitboard
1Correctionofamodelselect
2Replaceoutdoorpowercircuitboard.
3Replaceoutdoorcontrollercircuitboard.
U9
(4220)
Detailed
codes
UF
(4100)
Compressor overcurrent interruption
(When compressor locked)
AbnormalifovercurrentofDCbusor
compressorisdetectedwithin30seconds
aftercompressorstartsoperating.
1Stopvalveisclosed.
2
Decreaseofpowersupplyvoltage
3Looseness,disconnectionor
converseofcompressorwiring
connection
4Defectivecompressor
5Defectiveoutdoorpowerboard
6 DIPSwitchsettingforselecting
modelisincorrectonthe
outdoorpowercircuitboard.
1Openstopvalve.
2Checkfacilityofpowersupply.
3 Correctthewiring(U·V·Wphase)to
compressor.Referto"10-9.TESTPOINT
DIAGRAM".(Outdoorpowercircuitboard).
4Checkcompressor.Referto"10-6.HOWTO
CHECKTHEPARTS".
5Replaceoutdoorpowercircuitboard.
6 CheckthattheDIPSwitchsettingiscor-
rectontheoutdoorpowercircuitboardby
referringto"ModelSelect"in"1)Function
ofswitches"in"10-10.FUNCTION
OFSWITCHES,CONNECTORSAND
JUMPERS".
UH
(5300)
Current sensor error
• Itisabnormalfor38Atheinputcurrentor
10secondscontinuous34Aormore.
1Defectivecircuitofcurrent
sensoronoutdoorpowercircuit
board
2Decreaseofpowersupply
voltage
1Replaceoutdoorpowercircuitboard.
2Checkthefacilityofpowersupply.
UL
(1300)
Abnormal low pressure (63L worked)
Abnormalif63Lisworked(under−4PSIG
[−0.03MPa])duringcompressoroperation.
63L:Low-pressureswitch
(A42Nonly)
1Stopvalveofoutdoorunitis
closedduringoperation.
2Disconnectionorlooseconnec-
tionofconnector(63L)onoutdoor
controllerboard
3Disconnectionorloose
connectionof63L
4Defectiveoutdoorcontrollerboard
5Leakageorshortageofrefrigerant
6Malfunctionoflinearexpansion
valve
1Checkstopvalve.
2–4Turnthepoweroffandonagaintocheck
ifF3isdisplayedonrestarting.
IfF3isdisplayed,followtheF3processing
direction.
5Correcttoproperamountofrefrigerant.
6Checklinearexpansionvalve.
Referto"10-6.HOWTOCHECKTHE
PARTS".