EngA AF Series

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AF / DCU MANUAL
IOM-52 22 of 23 Apr 13 R2
REFRIGERATION
SeasonalMaintenance
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 Checkoperatingtemperatureandpressures.
 Theexternalsurfaceoffinnedcoilscanbecleanedusingalowpressurewatersprayandabrush.
Coilfinsareeasilydamaged.Donotusehighpressuresteamorwatertocleancoils;itwill
permanentlydamagethecoil.Whenusingcleaningadditivesorsolutionstheymustbecompatible
withthecoilmaterialsorcoatings.Useafincombtostraightenanydamagedorbentfins.
 Inspectrefrigerantlinesforevidenceofoilleaks.
 Checkcondenserfansandtightensetscrews.
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NOTE:Airflowisrestrictedbydirtycoils,slippingfanbeltsetc.Thiswillreducecapacity.
PressureControls
Encapsulatedpressurecontrolshavefixedsettingsandarenotadjustable.Mostpressurecontrolshave
thesetpointmarkeddirectlyonthecontrol.Thefollowingtableshowstypicalcutinandcutoutsetpoint
usingsaturatedtemperature;refertorefrigerantspecificsaturatedtemperature/pressuretablesto
converttopressure.
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TYPICALSETTINGS(SaturatedTemperature)
PressureControls CutIn CutOut
LowPressure 35°F(1.7°C) 15°F(‐9.4°C)
HighPressure Manual 150°F(65.6°C)
HighPressure(WaterCooled) 105°F(40.6°C) 125°F(51.7°C)
CondenserFan
Varioussettingstomaintainsaturatedcondensing
temperaturebetween85°Fto125°F(29.4°Cto51.7°C)
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Note:Specializedapplicationsordifferentrefrigerantsmayhavepressurecontrolsettingsoutside
typicalsettings.Referdirectlytomountedpressurecontrols,wiringdiagramand/orunitfunctionfor
specificdetails.
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Note:Equipmentwithareceivercanusehighpressurecontrolswiththelowersettingofthanthat
notedabove,themaximumratedworkingpressureofthereceiver,90%ofthepressurereliefvalve
rating.
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