IEC HPY 12 - Motor and Blower Assembly Maintenance; Electrical Wiring and Controls Maintenance

Fan Coils
INSTALLATION, OPERATION, & MAINTENANCE MANUAL
13
SECTIONTHREE–NormalOperation&PeriodicMaintenance,Cont'd.
Motor/Blower Assembly
Thetypeoffanoperationisdeterminedbythecontrol
componentsandtheirmethodofwiring.Thismayvary
fromunittounit.Refertothewiringdiagramthatis
attachedtoeachunitforthatunit’sindividualoperating
characteristics.
Allmotorshavepermanentlylubricatedbearings.Noeld
lubricationisrequired.
Shouldtheassemblyrequiremoreextensiveservice,the
motor/blowerassemblymayberemovedfromtheunit
tofacilitatesuchoperationsasmotororblowerwheel/
housingreplacement,etc.
Dirtanddustshouldnotbeallowedtoaccumulateonthe
blowerwheelorhousing.Thiscanresultinanunbalanced
blowerwheelconditionwhichcandamageablower
wheelormotor.Thewheelandhousingmaybecleaned
periodicallyusingavacuumcleanerandabrushtaking
carenottodislodgethefactorybalancingweightsonthe
blowerwheelblades.
Coil
Coilsmaybecleanedbyremovingthemotor/blower
assembliesandbrushingtheenteringairfacebetween
nswithastiffbrush.Brushingshouldbefollowedby
cleaningwithavacuumcleaner.Ifacompressedairsource
isavailable,thecoilmayalsobecleanedbyblowingair
throughthecoilnsfromtheleavingairface.Thisshould
againbefollowedbyvacuuming.Unitsprovidedwiththe
propertypeofairlters,replacedregularly,willrequire
lessfrequentcoilcleaning.
Electric Resistance Heater Assembly
Electricresistanceheaterstypicallyrequirenonormal
periodicmaintenancewhenunitairltersarechanged
properly.Theoperationandservicelifemaybeaffected
byotherconditionsandequipmentinthesystem.The
twomostimportantoperatingconditionsforanelectric
heaterareproperairowandpropersupplyvoltage.High
supplyvoltageand/orpoorlydistributedorinsufcientair
owovertheelementwillresultinelementoverheating.
Thisconditionmayresultintheheatercyclingonthehigh
limitthermalcutout.Sheathheatershaveautomaticreset
switchesonly.Open-stripheatershaveanautomaticreset
switchwithaback-up,high-limitthermalswitch.
Automaticresetswitchesareasthenameimplies,they
resetautomaticallyaftertheheaterhascooleddown.
High-limitthermalswitchesmustbereplacedoncethe
circuithasbeenbroken.Thehigh-limitthermalcutout
deviceisasafetydeviceonly,andisnotintendedfor
continuousoperation.Withproperunitapplicationand
operation,thehigh-limitthermalcutoutwillnotoperate.
Thisdeviceonlyoperateswhenaproblemexists,andANY
conditionthatcauseshigh-limitcutoutMUSTbecorrected
immediately.Highsupplyvoltagealsocausesexcessive
amperagedrawandmaytripthecircuitbreakerorblow
thefusesontheincomingpowersupply.
Afterproperairowandsupplypowerareassured,
regularltermaintenanceisimportanttoprovideclean
airovertheheater.Dirtthatisallowedtodepositonthe
heatingelementwillcausehotspotsandeventualelement
burnthrough.Thesehotspotswillnormallynotbeenough
totripthehigh-limitthermalcut-outdevice,andmaynot
beevidentuntilactualheaterelementfailure.
Electrical Wiring and Controls
Theelectricaloperationofeachunitisdeterminedbythe
componentsandwiringoftheunit.Thismayvaryfrom
unittounit.Consultthewiringdiagramattachedtothe
unitfortheactualtypeandnumberofcontrolsprovided
oneachunit.
Theintegrityofallelectricalconnectionsshouldbe
veriedatleasttwiceduringtherstyearofoperation.
Afterwards,allcontrolsshouldbeinspectedregularly
forproperoperation.Somecomponentsmayexperience
erraticoperationorfailureduetoage.Wallthermostats
mayalsobecomecloggedwithdustandlint,andshould
beperiodicallyinspectedandcleanedtoprovidereliable
operation.
Whenreplacinganycomponentssuchasfuses,
contactors,orrelays,useonlytheexacttype,sizeand
voltagecomponentasfurnishedfromthefactory.Any
deviationwithoutfactoryauthorizationcouldresultin
personnelinjuryordamagetotheunit.Thiswillalso