Danfoss Turbocor TT Series

Figure 2-2 Cooling Inlet Adapter
Liquidrefrigerantisinternallychanneledtotwo(2)solenoidvalves.Thesevalveshaveintegralorificesthatactas
expansiondevicestocoolthecompressormotor,shaft(rotor)andpowerelectronics.TTS300andTGS230
compressorshavethesesolenoidsarrangedsothatallcomponentsarecooledinserieswitheachotherandthe
solenoidsactastwo(2)stagesofcoolingcapacity.TheTTS350,TTS400,TTS450,TTS500,TTS700,TTH375,TGS310,
TGS380,TGS390,TGS490,TGS520,andTGH285compressorshaveseparatecoolingpathsformotorandpower
electronics.Thesecoolingmethodsareidentifiedasserialorsplitcooling.
Serialcoolinghasitsreturnpointtotheinletofthefirst-stageimpeller,thuscoolingallcomponentswithrefrigerant
evaporatingatthesaturatedsuctiontemperature.Inserialcoolingversions,SolenoidOne(1)isopenedifany
temperaturereachesits“turnon”pointandSolenoidTwo(2)isopenedifanytemperaturereachesasecond“turn
on”pointvalue.RefertoFigure2-5CompressorCoolingPath-TTS300/TGS230onpage37.
Thesplitcoolinghasthemotor/shaftcoolingcircuitreturntothefirst-stageimpellerinletandthepowerelectronics
returntothesecond-stageimpellerinlet.Thisensuresahigherevaporating(cooling)temperaturetominimize
condensationaroundthepowerelectroniccomponents.Inthesplitcoolingversion,SolenoidOne(1)isopenedif
eitherthecavitytemperatureorthemotortemperaturereachesits“turnon”pointandSolenoidTwo(2)isopenedif
theInverterorSCRtemperaturereachesits“turnon”point.RefertoFigure2-4SplitCoolingPath-(TTS/TGS(Except
TTS300/TGS230SerialCooling))onpage36.
Mediumtemperature(MT)versioncompressorsrequiretheirmotorcoolingsuctionlinetobeventedexternallyto
themainsuctionlinethroughanevaporatorpressureregulating(EPR)valve.Thisvalveisrequiredtoensurethat
evaporatingtemperaturescoolingthemotorandelectronicsdonotgettoocold.TheEPRvalveshouldbeadjusted
tomaintainaminimumevaporationtemperatureof0.8°C(34°F).RefertotheTTS/TGS/TTH/TGHApplicationsManual
forfurtherdetails.
SerialCoolingcompressorscanbeidentifiedbyhavingonlyone1/4inchflareSchraderconnectionadjacenttothe
mainmotorcoolingliquidconnection,whileasplitcoolingmodelwillhavetwo(2).These1/4inchflareconnections
accesstherefrigerantfeedstothecomponentsbeingcooledandbypassthesolenoidvalves.Aminimumpressure
ratioof1.5andafullliquidsealatthecompressorisrequiredtoensureproperandcorrectcompressorcooling.
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