Danfoss TTS400

Compressor Status
Description
Trigger Method Troubleshooting
Verificationonpage73.
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Verifythesolenoidactuators.RefertoSection4.6.3SolenoidVerificationonpage73.
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VerifytheSerialDriver.RefertoSection4.26.3SerialDriverVerificationonpage217.
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ReviewthefaultlogforactualInvertertemperatureandotherconditionsthatare
recordedatthetimeoffault.
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TheInverterrequiresreplacementiftheembeddedtemperaturesensorisdetermined
faulty.
HighDischarge
TemperatureFault
AFT
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Suggestsinsufficientcharge(i.e.,lowgas),thecondensertemperaturehasincreased,
checkvalvehasfailedtoopenorthecompressorhasbeenrunninginsurgecondition
foranextendedperiodoftime.
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Checkthechillergascharge,enteringcondenserair/waterconditionsandoperational
settings.
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Verifycheckvalveopensduringcompressoroperation.
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Verifythedischargepressure/temperaturesensor.RefertoSection4.32.3
Pressure/TemperatureSensorVerificationonpage246.
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Reviewthefaultlogforactualdischargetemperatureandotherconditionsthatare
recordedatthetimeoffault.
LowSuctionPressure
Fault
DFT
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Suggestsinsufficientcharge,insufficientsystemload,orasuddendropinevaporator
enteringair/watertemperatureorflow.
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Checkthecharge,systemloadandenteringair/waterconditions.
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Reviewthefaultlogforactualsuctionpressureandotherconditionsthatarerecordedat
thetimeoffault.
HighDischarge
PressureFault
AFT Consequence:
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ResultsinanInstantaneousLock-OutFault-pre-CC4.0.0
Recommendation:
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Suggeststhecondensermaybefaultyorinsufficientair/waterflow.
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Checkthecondenserandair/waterflow.
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Reviewthefaultlogforactualdischargepressureandotherconditionsthatarerecorded
atthetimeoffault.
3-PhaseOver-Current
Fault
AFT Consequence:
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Duringstartupmode,allalarmsareignoredbythecontrolsystem,butfaultsarenot.
Therefore,whentheFLAcurrent(3-PhaseAlarmLimit)isreached,thecompressorwill
continuetoaccelerateifstartuprequirementsarenotsatisfied.AfterStartupis
complete,alarmswillslowthecompressorspeed.ResultsinanInstantaneousLockOut
Fault-pre-CC4.0.0.
Requiresapowercycletoreset.
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Indicatesthecompressorisdrawingcurrentgreaterthanthe3-PhaseCurrentFault
Limit.
Recommendation:
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Reviewthefaultlogforrecorded3-PhaseCurrentlevel,demand,enteringair/water
temperature(ifavailable)andotherconditionsthatarerecordedatthetimeoffault.
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Usualcausesarestartspeedsettoohigh,minimumpressureratiosettoohighatstart-
up,powercontrolintegral(loop)gainsettoohigh.Canalsoberelatedtosudden
increaseinload/demandorsystemchanges.
HighCavity
TemperatureFault
AFT Consequence
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Indicatesthemotorcoolingisinsufficient.
CAUTION:RepeatedoccurrencesofthisfaultcanresultinshaftdemagnetizationorBackEMFislow
Page 256 of 294 - M-SV-001-EN Rev. H 1/23/2023