EngA AF Series

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AF / DCU MANUAL
IOM-52 18 of 23 Apr 13 R2
10. Setupthehotgasbypassvalve(optional).Usingapressure‐temperaturechartfindtherefrigerant
pressurethatcorrespondstoatemperatureof34°F(1°C).
Createalowloadconditionontheevaporatorbyrestrictingtheairflowacrosstheevaporator.
Adjustthehotgasbypassregulatorsothatitwillstarttoopenatthepressurecorrespondingto
34°F(1°C).IfthehotgassystemisequippedwithadesuperheatingTXvalve,measurethe
superheatatthecompressorandensurethevalveisworking.
11. CheckthesettingsoftheCondenserFanCyclingControls(CFC’s),adjustasrequired.
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FLUSHINGANDDEGREASINGOFWATERANDGLYCOLCOILS
Coiltubingmaycontainmaterialorresiduefrommanufacturing,transportationorstorage.Toprevent
possibledamagetoothercomponentsinthesystem,thecoilsmustbeflushedanddegreased.Consulta
qualifiedwatertreatmentspecialist.
HEATTRANSFERFLUIDS
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Thecoil(s)providedhavebeenselectedforusewithaspecificheattransferfluidasshownonthe
SubmittalRecord.Useofotherfluidswillresultindifferentperformanceandcandamagethecoil(s).
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Itisimperativetoproperlyselectandapplyheattransferfluidsusedinheatingandcoolingsystems.
Untreated,improperlytreatedorimproperuseoffluidsoruseoffluidsnotapprovedforusein
commercialheatingandcoolingsystemscandamagecoilsandsystemcomponents.Forselectionand
applicationofheattransferfluids,alwaysfollowthemanufacturers’recommendationsincluding
treatment,mixingandfilling.Warrantywillbevoidifcoildamageresultsfrommisapplicationorimproper
treatmentoftheheattransferfluid.
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SHUTDOWNPROCEDURE
Warning:
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Electricalshockordeathcanoccurifinstructionsarenotfollowed.Thisequipment
containsmovingpartsthatcanstartunexpectedly.Injuryordeathcouldoccurif
instructionsarenotfollowed.Allworkshouldbeperformedbyaqualifiedtechnician.
Alwaysdisconnectpowerbeforeservicing.DONOTbypassanyinterlockorsafetyswitches
underanycircumstances.
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1. Shutdown
Toshuttheunitdownforashorttime(suchasforinspectionorservice).Shutoftheserviceswitch
inthemaincontrolpanelthenturnoffthemaindisconnect.
2. Re‐StartafterShutdown
Turnonmaindisconnectfortheunit.Turnontheserviceswitchinthemainelectricalcontrol
panel.
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