BAC 3240C - Corrosion Protection

WWW.BALTIMOREAIRCOIL.COM
20
Mechanical Make-up Valve Assembly
Aoat-operatedmechanicalwatermake-upassemblyisfurnishedasstandardequipment
onthecoolingtower.Thestandardmake-upassemblyconsistsofacorrosionresistant
make-upvalveconnectedtoaoatarmassemblyactuatedbyapolystyrene-lledplastic
oat.Theoatismountedonanall-threadrodheldinplacebywingnuts.Thecoldwater
basinoperatingwaterlevelcanbeadjustedbyrepositioningtheoatandall-threadrod
usingthewingnutsprovided.
• Inspectthemake-upvalveassemblymonthlyandadjustifnecessary.
• Inspectthevalveannuallyforleakage.Replacethevalveseatifnecessary.
• Maintainthemake-upwatersupplypressurebetween15psigand50psigforproper
operation.BACrecommendsapressureregulatorvalve(providedbyothers)for
pressuresover50psig.
• Settheinitialbasinwaterlevelbyadjustingthewingnutssothatthemake-upvalveis
completelyclosedwhenthewaterlevelinthecoldwaterbasinisattheoperatinglevel
asstatedinTable 1onpage 9.
• Withthedesignthermalloadandtheaveragewaterpressure(15to50psig)atthe
valve,theabovesettingwillproduceoperatingwaterlevelsasstatedinTable 1on
page 9.
• Ifthethermalloadislessthanthedesignloadatthetimeofunitstart-up,the
proceduremayproduceoperatinglevelsgreaterthanthoseshowninTable 1.If
operatinglevelsarehigherthanspecied,readjusttheoatinordertoattainthe
recommendedoperatinglevel.
• Closelymonitorthewaterlevelinthecoldwaterbasinandadjustthelevelifnecessary
duringtherst24hoursofoperation.
• Operatingattherecommendedwaterlevelwillensurethattheunitbasincontains
sufcientwatervolumetopreventairentrainmentinthecirculatingpumpduring
systemstart-upandprovidessufcientexcessbasincapacitytoacceptthetotal
systempull-downvolume.
Optional Electric Water Level Control Package
Asanoption,anelectricwaterlevelcontrolpackageisavailableinlieuofthemechanical
make-upassembly.Thepackageconsistsofaprobe-typeliquidlevelcontrolassembly
andaslow-closingsolenoidvalve.Stainlesssteelelectrodes,factory-setatpredetermined
lengths,extendfromanelectrodeholderintothecoldwaterbasin.Formoreinformation,
refertotheElectric Water Level Control Operation & Maintenance Manualavailableat
www.BaltimoreAircoil.com.
• Cleanthestainlesssteelelectrodesperiodicallytopreventaccumulationsofscale,
corrosion,sludge,orbiologicalgrowth,whichcouldinterferewiththeelectricalcircuit.
• Thewaterlevelismaintainedattherecommendedoperatinglevelregardlessofthe
systemthermalload.Therefore,itisnotrecommendedthattheoperatinglevelbe
adjusted.
•
Duringthestart-upofunitsequippedwiththeelectricwaterlevelcontrolpackage,
bypassthecontrolunitinordertolltheunittotheoverowconnection.
NOTE: If the unit has been ordered
with the optional electric water
level control package or is intended
for remote sump application, a
mechanical water make-up valve
will not be provided.