BAC 3872C User Manual

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• ToavoidbiologicalcontaminationandminimizetheriskofLegionella,initiatethe
biocidetreatmentprogramatstart-upandcontinueonaregularbasisthereafterin
accordancewiththetreatmentsupplier’sinstructions.
• Bleed/blowdownorchemicaltreatmentusedforcorrosionandscalecontrolaloneis
notadequateforcontrolofbiologicalcontamination.
• Introducesolidorgranularbiocidesthroughachemical“pot”feederinstalledin
parallelwiththesystemcirculatingpump.Dilutedliquidbiocidesmaybeadded
directlytothecoldwaterbasin.
• Ifozonewatertreatmentisused,atnopointshouldconcentrationsexceed0.5ppmto
avoidcorrosion.
Chemical Treatment Requirements
Chemicaltreatmentprogramsmustmeetthefollowingrequirements:
• Thechemicalsmustbecompatiblewiththeunitmaterialsofconstructionaswellas
othermaterialsusedinthesystem(pipe,heatexchanger,etc.).
• Chemicalscaleandcorrosioninhibitors,particularlyacid(ifused),shouldbe
introducedintothecirculatingwaterthroughautomaticfeeders.Thisshouldbedone
atapointinthesystemwheretotalmixinganddilutionoccurbeforereachingthe
evaporativecoolingequipment.Thepreferredinjectionpointforchemicalscaleand
corrosioninhibitorsisonthedischargesideofthesystemcirculatingpump(s).These
chemicalsshouldnotbebatch-feddirectlyintotheunit’scoldwaterbasinorwater
distributionsystem,asthiscanseverelydamageareasdirectlycontacted.
• Whenchlorineisaddedtothesystem,freeresidualchlorineshouldnotexceed1ppm,
exceptduringstart-upifbiologicalshocktreatmentisutilizedduringtreatment.Refer
to“Start-Up”onpage 5forlimits.Exceedingthislimitmayacceleratecorrosion.
Passivation
• Passivationistheformationofaprotective,passive,carbonatelayerongalvanized
steelsurfaces.
• Toprovidemaximumprotectionfromcorrosiononnewlyinstalledunitstakespecial
measurestopassivategalvanizedsteelsurfaces.
• Toensureproperpassivationofthegalvanizedsteel,keepthepHofthecirculating
waterbetween7.0to8.2forfourtoeightweeksafterstart-up,oruntilnewzinc
surfacesturndullgrayincolor.
• IfwhiterustformsongalvanizedsteelsurfacesafterthepHisreturnedtonormal
servicelevels,itmaybenecessarytorepeatthepassivationprocess.
NOTE: Stainless steel cold water
basins and basins protected by
the TriArmor
®
Corrosion Protection
System or thermosetting hybrid
polymer do not require passivation.
However, if the upper structure is
galvanized steel, passivation is
required on the galvanized area.

BAC 3872C Specifications

General

Brand	BAC
Model	3872C
Category	Air Conditioner
Language	English