Danfoss TTS400

l
VerifytheDC-DCConverter.RefertoSection4.24.2DC-DCConverterVerificationonpage204.
l
VerifythePWM.RefertoSection4.28.3PWMVerificationonpage226.
l
Verifythebearings.RefertoSection4.29.3BearingVerificationonpage230.
3. AnopenF2fusemayindicateaproblemwiththePottedDC-DCConverter.
l
VerifytheDC-DCConverter15VACinputresistance(PottedDC-DConly).RefertoSection4.24.2.3
InputResistanceMeasurementonpage205.
4. AnopenF3orF6fusemayindicateaproblemwiththeSoftStartCircuitBoard.
l
VerifytheSCRsandSCRgates.RefertoSection4.18.2.1DiodesVerification-Two-HoleMounton
page142.
l
Replacethefuse.
l
Reapplypower.
l
Ifthefusefailsagain,replacetheSoftStart.
5. AnopenF4orF5fusemayindicateaproblemwiththeSoftStartTransformers,SoftStartCircuitBoard,
orDC-DCConverter.
l
VerifytheDC-DC15VACinputresistance(PottedDC-DConly).RefertoSection4.24.2.3Input
ResistanceMeasurementonpage205.
l
VerifytheSCRsandSCRgates.RefertoSection4.18.2.1DiodesVerification-Two-HoleMounton
page142.
l
Ifnofaultycomponentisidentified,replacethefuseandreapplypower.
l
Ifthefusefailsagain,replacetheSoftStart.RefertoSection4.14.3SoftStartRemovaland
Installationonpage117.
5.5.3 Troubleshooting an Open Interlock
1. Verifytheinterlock.RefertoSection4.3.2.3InterlockVerificationonpage63.
2. Ensurethereisnoexternalpowerappliedontheinterlockcircuit.
3. IftheInterlockcircuitisdetermineddamagedandwillnotclose,removethewirefromtheI/LOCK-
(neg)attheJ2connectoroftheI/OBoard.
4. MovethewiretotheSPEED-(neg)attheJ2connectoroftheI/Oboard.
5. ThiswillallowtheinterlockcircuittocloseuntilareplacementBMCCisinstalled.
6. AfterreplacingtheBMCC(refertoSection4.27BMCConpage220),replacethewiretotheI/LOCK-
(neg)attheJ2connectoroftheI/Oboard.
5.5.4 Troubleshooting the Inverter

• • • CAUTION • • •
Repeatedrotormaybelockedorsinglephaseovercurrentfaultscancauseshaftdemagnetization.ItisimportanttorepairanInverter
failurebeforethecompressorisdamagedbeyondfieldrepair.

1. Downloadthefaultandeventlog.
2. Reviewthefaultandeventlogforany“InverterError”faults.
l
Presenceofan“InverterError”faultindicatesprobablefailureoftheInverter.ReplacetheInverter.
l
Ifno“InverterError”faultispresent,continuewiththenextstep.
3. VerifytheInverter.RefertoSection4.22.2InverterVerificationonpage176.
4. IftheInverterverificationpasses,buthecompressorwillnotrun,refertoSection4.23.4.1Stator
InsulationVerificationonpage195andSection4.23.4.2StatorResistanceVerificationonpage195.
M-SV-001-EN Rev. H-1/23/2023 Page 273 of 294