Danfoss Turbocor TT Series

5.2.3 Bearing Fault Troubleshooting

Table 5-9 Bearing Status
Bearing Fault
Description
Trigger
Method
Troubleshooting
Startup
CalibrationCheck
Fault
INS
l
Duringcompressorstart-up,thestoredbearingcalibrationisverified.Indicatesthatthecalibration
failedduringcompressorstart-up.ManuallycalibratethebearingsandsavetoEEPROM,cyclethe
power.
l
Reviewthecalibrationreporttodetermineconditionsrelatedtothefault.
l
Ifthebearingscannotpasscalibrationafterthree(3)attempts,verifythePWM(refertoSection
4.28.3PWMVerificationonpage226),bearingsensors(refertoSection4.30.3BearingSensor
Verificationonpage236),andbearings(refertoSection4.29.3BearingVerificationonpage230).
Bearing
Displacement
Fault
INS
l
Theshaftpositionhasbeenmeasuredoutsidethebearingdisplacementmaximuminoneofthe
fivebearingpositions.
l
Thisfaultcanbetheresultofsystem-relatedissues,suchasEXVcontrolissues(i.e.,starvingthe
evaporatororpumpingliquid),operatingatthesurgeline,checkvalvefailure,orIGVfailure.
l
ReviewFaultandEventLogdetailstodetermineconditionsrelatedtothefault.Usingthe
CompressorConfigurationtool,settheControlModetoManual.UsingtheCompressorMonitor,
levitatetheshaftandrecordthebearingforces.Greaterthan2Aindicatesabearingissue.
l
Manuallycalibratethebearings,savetoEEPROMandidentifyifbearingforcesimprove.
l
Ifthebearingscannotbecalibratedafterthreeattempts,verifythePWM(refertoSection4.28.3
PWMVerificationonpage226),bearingsensors(refertoSection4.30.3BearingSensorVerification
onpage236)andbearings(refertoSection4.29.3BearingVerificationonpage230).
l
Reviewthecalibrationreporttodetermineconditionsrelatedtothefault.RefertoSection5.3.5
CalibrationReportAnalysisonpage266.
Bearing
OvercurrentFault
INS
l
Indicatesthatthecurrentdrawnbythebearingexceedsthemaximumampsinoneofthefive(5)
bearingpositions.UsingtheCompressor Configuration Tool,settheControlModetoLevitateOnly
Mode.UsingtheCompressor Monitor,levitatetheshaftandrecordthebearingforces.Greaterthan
2Aindicatesanissue.
l
Manuallycalibratethebearings,savetoEEPROMandidentifyifbearingforcesimprove.Ifthe
bearingscannotbecalibratedafterthree(3)attempts,verifythePWM(refertoSection4.28.3
PWMVerificationonpage226),bearingsensors(refertoSection4.30.3BearingSensorVerification
onpage236)andbearings(refertoSection4.29.3BearingVerificationonpage230).
l
Reviewthecalibrationreporttodetermineconditionsrelatedtothefault.RefertoSection5.3.5
CalibrationReportAnalysisonpage266.

5.3 Bearing Calibration
5.3.1 When to Calibrate the Bearings

5.3.1.1 Calibration when Commissioning
Abearingcalibrationcanbeperformedatcommissioningforthepurposeofcomparingcurrentcalibrationvaluesto
factorysavedcalibrationvalues.Afterthecalibrationhasbeenperformed,acalibrationreportshouldbecreatedand
savedforfuturecomparison.ThereisnorequirementtosavethecalibrationtoEEPROMwhencommissioningthe
compressor.
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