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6
After 24 hours of operation
under thermal load, perform the
following services:
9
Check the tower for any
unusual noise or vibrations.
9
Check the operating water
level in the hot and cold water
basins.
9
Adjust the make-up valve if
necessary.
9
Check the belt tension and
readjust if necessary.
9
Inspect the spray nozzles and
heat transfer section.
• Adjustthevalve(suppliedbyothers)inthetowerbleedlinetoachievethedesired
bleedratebyclosingoropeningthevalve.
• Inspectthenozzlesandheattransfersectionasdescribedin“WaterDistribution
System”onpage 19 (Figure 6).
• Executeoneofthefollowingbiocidetreatmentprogramswhileoperatingthe
circulatingpumpandpriortooperatingtheunitfans:
– Resumetreatmentwiththebiocidethatwasusedpriortoshutdown.Operatethe
pumponlywhilemaintainingthemaximumrecommendedbiocideresidualfora
sufcientduration(residualandtimewillvarywiththebiocide)asrecommended
bythewatertreatmentsupplier.Startthefanonlyafterthistreatmentperiodis
completed.
– CheckthepHofthecirculatingwaterand,ifnecessary,adjustitto7.0-7.6pH.
Then,runningthepumponly,treatthesystemwithsodiumhypochloritetomaintain
alevelof4to5mg/l(ppm)freechlorine(asCl
2
)overasixhourperiod.Testkitsfor
measuringthefreeresidualofchlorinearecommerciallyavailable.Startthefanonly
afterthistreatmentperiodiscompleted.
• Forunitswiththeoptionalgeardrivesystem,seepage 13forinitialstart-up.
• Forinitialstart-up,brieyenergizethefanmotor(s)andnotethedirectionofrotation.
Thefanshouldrotateinthedirectionindicatedbythearrowonthefancowl.
• Runthefaninmanualmodeforseveralminutestocheckforanyunusualnoiseor
vibrations.
• FortheBALTIGUARD™FanSystem,BALTIGUARDPLUS™FanSystemor2-speed
motors:checkthatthestarterincorporatesa15secondtimedelaywhenswitching
fromhightolowspeed.
• Checktheoperationofthevibrationcutoutswitch(seepage 32).
• Oncethecoolingtowerisoperating,checkthecurrentandvoltageofallthreephases
(legs)ofthefanmotorwithaheatloadonthetowerunderwarmambientconditions.
Thecurrentmustnotexceedthemotornameplaterating.
• ForunitswithVFDs,seepage 35.
• ForunitswiththeoptionalElectricWaterLevelControl,seepage 20.
Extended Shutdown
Perform the following services whenever the unit is shutdown in excess of three days:
• Iftheunitismountedonvibrationisolatorsorisolationrails(byothers),refertothe
manufacturer’sguidelinesbeforeloading/unloadingweightfromtheunit.
• Disconnect,lock-out,andtag-outallfansandpumps.
• Closetheshut-offvalveinthemake-upwaterline(suppliedbyothers)anddraincold
waterbasinandallexposedwaterpiping.Heattraceandinsulateallexposedpiping.
• Tominimizetheriskofbiologicalcontaminationduringshutdown,itisrecommended
theentiresystembedrained.
• Cleanalldebris,suchasleavesanddirt,fromtheinteriorandexterioroftheunit,
includingthelouversortheoptionalcombinedinletshields.
• Cleanandushthecoldwaterbasinwiththebasinstrainerinplace.
• Leavethecoldwaterbasindrainopensorainandmeltingsnowwilldrainfromthe
unit.
ATTENTION: Check to ensure the
controls for the fan motor are set
to allow a maximum of six on-off
cycles per hour to prevent motor
overload.
DANGER: Do not perform any service
on or near the fans, motors, and
drives, or inside the unit without
first ensuring that the fans and
pumps are disconnected, locked
out, and tagged out.