ABB MT series Technical specifications

Fläkt Woods 8265 GB 2011.10 1 Specifications are subject to alteration without notice
Installation and maintenance instruction
Fläkt Woods three phase asyncronous motor
Manufacturer: ABB
Machine Instructions

NOTE!
 Theseinstructionsmustbefollowedtoensure
 safeandproperinstallation,operationandmain-
 tenanceofthemotor.Theyshouldbebroughtto
 theattentionofanyonewhoinstalls,operatesor
 maintainsthisequipment.Ignoringtheinstruc-
 tionmayinvalidatethewarranty.

Declaration of Conformity
DeclarationsofConformitywithrespecttotheLowvol-
tageDirective73/23/EECamendedbyDirective93/68
EECareissuedseparatelywithindividualmachines.

TheDeclarationofConformityalsosatisfiestherequire-
mentsofaDeclarationofIncorporationwithrespect
totheMachineryDirective89/392/EEC,amendedby
91/368/EEC,93/44/EECand93/68/EEC.
Validity
TheinstructionsarevalidforthefollowingABBelectrical
machinetypes,inbothmotorandgeneratoroperation.

seriesMT*,MBT*,MXMA,
seriesM2A*/M3A*,M2B*/M3B*,M2C*/M3C*,M2F*/
M3F*,M2L*/M3L*,M2M*/M3M*,M2R*/M3R*,

inframesizes63-400.

(Additionalinformationmayberequiredforsome
machinetypesduetospecialapplicationand/ordesign
considerations.)
Putting into service (starting)
Reception check
Immediatelyuponreceiptcheckthemachineforexternal
damageandiffound,informtheforwardingagentwith-
outdelay.
Checkallratingplatedata,especiallyvoltageandwinding
connection(starordelta).Thetypeofbearingisspecified
ontheratingplatefromsize112andlarger.
Turnshaftbyhandtocheckfreerotation,removetrans-
portlockingifemployed.
Motors equipped with roller bearings:Runningthe
motorwithnoradialforceappliedtotheshaftmay
damagetherollerbearing.
Motors equipped with angular contact bearing:
Runningthemotorwithnoaxialforceappliedintheright
directiontotheshaftmaydamagetheangularcontact
bearing.
Motors equipped with regreasing devices:
Whenstartingthemotorforthefirsttime,applyatleast
thespecifiedquantityofgreaseuntilnewgreaseforced
outofthegreaseoutlet.Fordetailsseesection“Machines
withrelubricationsystem”onpage6.
Insulation resistance check
Measureinsulationresistancebeforecommissioningand
whenwindingdampnessissuspected.
Resistance,measuredat25°C,shallexceedthereference
value,i.e.
10Mohm(measuredwith500VdcMegger)

Insulationresistancereferencevalueishalvedforeach
20°Criseinambienttemperature.
Ifthereferenceresistancevalueisnotattained,thewinding
istoodampandmustbeovendried.
Oventemperatureshouldbe90°Cfor12-16hoursfollowed
by105°Cfor6-8hours.
Drainholeplugs,iffitted,mustberemovedduringheating.
Windingsdrenchedinseawaternormallyneedtobe
rewound.
Direct-on-line or star/delta starting
Theterminalboxonstandardsinglespeedmachines
normallycontains6windingterminalsandatleastone
earthterminal.
Earthingmustbecarriedoutaccordingtolocalregulations
beforethemachineisconnectedtothesupplyvoltage.
Thevoltageandconnectionarestampedontheratingplate.
Direct-on-line starting (DOL):
YorΔwindingconnectionsmaybeused.eg660VY,380VΔ
indicatesY-connectionfor660VandΔ-connectionfor380V.
Star/Delta starting (Y/Δ) :
Thesupplyvoltagemustbeequaltotheratedvoltageof
themachineinΔ-connection.
Removeallconnectionlinksfromtheterminalblock.
Fortwo-speed,singlephaseandspecialmachines,supply
connectionmustfollowtheinstructionsinsidethetermi-
nalbox.
Terminals and direction of rotation
Directionofrotationisclockwisewhenviewingtheshaft
faceatthemachinedriveend,whenthelinephasesequence
L1,L2,L3isconnectedtotheterminalsasshowninthe
figure1.
Toalterthedirectionofrotation,interchangetheconnec-
tionofanytwolinecables.
Ifthemachinehasauni-directionalfan,ensurethatthe
directionofrotationisaccordingtothearrowmarkedon
themachine.
WARNING!
 Windingsshouldbedischargedimme-
 diatelyaftermeasurementtoavoidrisk
 ofelectricshock.

Fläkt Woods 8265 GB 2011.10 2 Specifications are subject to alteration without notice
Installation and maintenance instruction
Fläkt Woods three phase asyncronous motor
Manufacturer: ABB
Use
Operating conditions
Themachinesareintendedforuseinindustrialdrive
applications.
Normalambienttemperaturelimitsare-25°Cto+40°C.
Maximumaltitude1000mabovesealevel.
Safety considerations
Themachineisintendedforinstallationandusedby
qualifiedpersonnel,familiarwithrelevantsafety
requirements.
Safetyequipmentnecessaryforthepreventionof
accidentsattheinstallationandoperatingsitemustbe
providedinaccordancewiththelocalregulations.
Points to observe
1.Donotusethemachinetostepon
2.Thetemperatureoftheoutercasingofthemachine
 maybehottothetouchduringnormaloperation.
3.Somespecialmachineapplicationsrequirespecial
 instructions(e.g.usingfrequencyconvertersupplies)
4.Liftinglugsmustonlybeusedforliftingthemotor.
 Theymustnotbeusedtoliftthemotorwhenitis
 attachedtootherequipment.

Handling
Operating conditions
Themachineshouldalwaysbestoredindoors,indry,
vibrationfreeanddustfreeconditions.
Unprotectedmachinedsurfaces(shaft-endsandflanges)
shouldprotectedwithanti-corrosivepaint.
Itisrecommendedthatshaftsberotatedperiodicallyby
handtopreventgreasemigration.
Anticondensationheaters,iffitted,shouldpreferablybe
energised.
Thecharacteristicsofelectrolyticcapacitors,iffittedto
single-phasemotors,willrequire“reforming”following
periodsofstorageexceeding1-2years.
ContactABBSalesOfficefordetails.
Transportation
Machinesfittedwithcylindrical-rollerand/orangular
contactbearingsmustbefittedwithlockingdevices
duringtransport.
Lifting
Onlyliftthemotorusingtheliftinglugs.
Thecenterofgravityofmotorswiththesameframemay
WARNING!
 Smallmotorswithsupplycurrent 
 directlyswitchedbythermallysensitive
 switchescanstartautomatically.
varyduetodifferentoutputs,mountingarrangementsand
auxiliaryequipment.
Checkthateyeboltsortheliftingeyesintegratedwiththe
motorframeareundamagedbeforelifting.Damaged
liftingeyesmustnotbeused.
Liftingeyeboltsmustbetightenedbeforelifting.Ifneeded
thepositionoftheeyeboltmustbeadjustedwithsuitable
washers.
Ensurethatproperliftingequipmentisusedandthatthe
sizesofthehooksaresuitablefortheliftinglugs.
Caremustbetakennottodamageauxiliaryequipmentand
cablesattachedtothemotor.directionofrotationisaccor-
dingtothearrowmarkedonthemachine.
Machine weights
Totalmachineweightcanvarywithinthesameframesize
(centerheight)dependingondifferentoutput,mounting
arrangementsandaddedfeatures.
Thefollowingtableshowsestimatedmaximumweights
formachinesintheirbasicversionsasafunctionofframe
material.
Onmachinesweightingmorethan25kg,theactualweight
isstatedontheratingplate.
Installation
Cooling
Normalambienttemperaturesshouldnotexceed40°C
(marinestandard50°C)ifstandardperformanceistobe
achieve.Checkthatthemotorhassufficientairflow.
Ensurethatnonearbyequipmentorsurfacesradiate
additionalheattothemotor.Formoreinformationabout
higherambienttemperaturesandcooling,see“theMotor
Guide”orcontactABBSalesOffice.
Aluminium Cast iron Steel
Frame
size
Weight
kg
Add.
for brake
Weight
kg
Weight
kg
63 6 - - -
71 8 5 13 -
80 12 8 20 -
90 17 10 30 -
100 25 16 40 -
112 36 20 50 -
132 63 30 90 -
160 110 55 175 -
180 160 65 250 -
200 220 - 310 -
225 295 - 400 -
250 370 - 550 -
280 - - 800 600
315 - - 1300 1000
355 - - 2300 2200
400 - - 3500 3000

Fläkt Woods 8265 GB 2011.10 3 Specifications are subject to alteration without notice
Installation and maintenance instruction
Fläkt Woods three phase asyncronous motor
Manufacturer: ABB
Foundation
Thepurchaserbearsfullresponsibilityforpreparationof
thefoundation.
Metalfoundationsshouldbepaintedtoavoidcorrosion.
Foundationsmustbeeven,andsufficientlyrigidtowith-
standpossibleshortcircuitforces.Theyshallbedimen-
sionedastoavoidtheoccurrenceofvibrationdueto
resonance.
Foundation studs
Boltthefoundationstudstothefeetofthemotorand
placea1-to-2mmshimbetweenthestudandthefeet.
Alignthemotordirectlyusingappropriatemeans.
Groutthestudswithconcrete,check,alignmentanddrill
holesforlocatingpins.
Drain holes
Alwayscheckthatopendrainholesfacedownward.
Machineswithclosableplasticdrainplugsaredelivered
withtheseopen.
Inextremelydustyenvironments,alldrainholesshould
beclosed.
Alignment
Correctalignmentisessentialtoavoidbearingfailures,
vibrationsandpossiblefracturedshaftextensions.
Slide rails and belt drives
• Fastenthemachinetothesliderailsasshowninfigure2.
• Placethesliderailshorizontallyonthesamelevel.
• Checkthatthemachineshaftisparallelwithdriven,
 ordriving,shaft.
• Anybeltmustbetensionedaccordingtothesupplier’s
 instructions.
Donotexceedthemaximumbeltforces(i.e.radialbearing
loading)statedintherelevantproductcatalogues.
Connection
Thenormalmachinedesigniswiththeterminalboxon
topandwithcableentrypossiblefrombothsides.
Somemachinesareavailable,asaspecialoption,withtop
mountedterminalboxesrotatable4x90°,andsomewith
sidemountedterminalboxes.
Availabilityofthesesolutionsisdescribedintheproduct
catalogues.
Unusedcableentriesmustbeclosed.
Aswellasmainwindingandearthingterminals,the
terminalboxcanalsocontainconnectionsforthermistors,
standstillheatingelements,bimetallic,switches,orPT
100resistanceelements.
WARNING!
 Excessivebelttensionwilldamage
 bearingsandcancauseshaftbreakage.
Connectiondiagramsforauxiliaryelementsarefound
insidetheterminalboxcover.
In frequency converter applications motorframe
externalearthingmustbeusedforequalisingthepoten-
tialbetweenthemotorframeandthedrivenmachine,
unlessthetwomachinesaremountedonthesame
metallicbase.FormotorframesizesaboveIEC280,use
0.75x70mmflatconductororatleasttwo50mm²round
conductors.Thedistanceoftheroundconductorsmust
beatleast150mmfromeachother.
Thisarrangementhasnoelectricalsafetyfunction;the
purposeistoequalisethepotentials.Whenthemotor
andthegearboxaremountedonacommonsteelfunda-
ment,nopotentialequalisationisrequired.
TocomplywithEMC-requirements,onlycablesand
connectorsapprovedforthispurpose.(Seeinstruction
forfrequencyconverters.)
Assembly and dismantling
General
Dismantlingandassemblyofmachinesmustbecarried
outbyqualifiedpersonnelusingonlysuitabletoolsand
workingmethods.
Bearings
Specialcareshouldbetakenwiththebearings.
Thesemustberemovedusingpullersandfittedby
heatingorusingspecialtoolsforthepurpose.How
toreplacebearingsisdescribedindetailinaseparate
instructionleafletavailablefromABBSalesOffice.
WARNING!
 Voltagemaybeconnectedatstandstill
 insidetheterminalboxforheating 
 elementsordirectwindingheating.
WARNING!
 Thecapacitorinsingle-phasemotors 
 canretainachargethatappears 
 acrossthemotorterminals,evenwhen
 themotorhasreachedstandstill.
0.75 mm
70 mm
> 150 mm
min 50 mm
Cables/wire s
Plate/strip
U1 V1
W1
PE 3 ~ M
Driven machinery
Potential equalisation

Fläkt Woods 8265 GB 2011.10 4 Specifications are subject to alteration without notice
Installation and maintenance instruction
Fläkt Woods three phase asyncronous motor
Manufacturer: ABB
Fitting coupling halves and pulleys
Couplinghalvesandpulleysmustbefittedusingsuitable
equipmentandtoolsthatdonotdamagethebearings.
Neverfitacouplinghalforpulleybyhammeringinto
placeorremoveitusingaleverpressedagainstthebody
ofthemachine.
Mounting accuracy of coupling half :
checkthattheclearancebislessthan0,05mmandthatthe
differencea1toa2isalsolessthan0,05mm.Seefigure3.
Balancing
Therotorofthemachineisdynamicallybalanced.
Asstandard,balancinghasbeencarriedoutusinghalf
key,andtheshaftismarkedwith a RED tape,withthe
text“Balancedwithhalfkey”.
Toavoidvibrationthecoupling-halforpulleymustbe
balancedwithhalfkeyafterthekeywayhasbeen
machined.
Intheeventofbalancingwithfullkeytheshaftis
markedwith a YELLOW tape,withthetext“Balanced
withfullkey”.
Toavoidvibrationthecoupling-halforpulleymustbe
balancedwithoutakeyafterthekeywayhasbeen
machined.
Incasebalancingwithout key,theshaftismarkedwith
a BLUE tape,withthetext“Balancedwithoutkey”.
Maintenance and lubrication
General inspection
- Inspectthemachineatregularintervals.
- Keepthemachinecleanandensurefreeventilation
 airflow.
- Checktheconditionofshaftseals(egV-ring)and
 replaceifnecessary.
- Checktheconditionofconnectionsandmountingand
 assemblybolts.
- Checkthebearingconditionbylisteningforunusual
 noise,vibrationmeasurement,bearingtemperature,
 inspectionofspentgreaseorSPMbearingmonitoring.
*Whenchangesofconditionoccur,dismantlethemachine,
checkthepartsandreplaceifnecessary.
Lubrication
Machines with permanently greased bearings
Machinesuptoframesize180arenormallyfittedwith
permanentlygreasedbearingsofeitherZor2Ztypes.
Bearingtypesarespecifiedintherespectiveproductcata-
loguesandontheratingplateofeachmotorfromsize112
andlarger.
WARNING!
 Bewareofallrotatingparts!
Asaquide,adequatelubricationcanbeachievedforthe
followingduration,accordingtoL1atambienttempera-
tureof25°C.
32000-45000dutyhoursfor4polemachines.1)
16000-26000dutyhoursfor2and2/4pole
machines.1)
Theshortertimesapplytolargerframesizes.
1) Dependingonapplicationandloadconditions,see
 applicableproductcatalogue.
 Hoursofoperationforverticalmotorsarehalfofthe
 abovevalues.
Machines with relubrication system
Relubricationprocedure:
- Removegreaseoutletplugiffitted.
- Pressfreshgreaseintothebearinguntilalloldgrease
 hasbeenforcedout
- Letthemotorrun1-2hourstoensurethatallexcess
 greaseisforcedoutofthebearing.Closethegrease
 outletplugiffitted.
Regreasemotorswhilerunning.Ifthisisnotpossible,
lubricationcanbecarriedoutwhilethemachineisata
standstill.Inthiscase,useonlyhalfthequantityofgrease,
thenrunthemotorforafewminutesatfullspeed.When
themotorhasstopped,theremainingquantityofgrease
canbeforcedinuntiltheoldgreasehasbeenreplaced.
After1-2runninghoursclosethegreaseoutletplug(if
fitted).
Thegreaseoutletplugmustberemovedpermanently
withautomaticlubrication.
Ifthemachineisfittedwithalubricationinformation
plate,followthevaluesgiven,otherwiseusethevalues
intable,page5.
ABBMotorspolicyistohavereliabilityasavitalissuein
bearinglubricationintervals.Thatiswhywefollowthe
L1-principle(meaningthat99%ofthemotorsaresure
tomaketheintervaltime).AccordingtoL1policythe
lubricationintervalsareasfollows:

Fläkt Woods 8265 GB 2011.10 5 Specifications are subject to alteration without notice
Installation and maintenance instruction
Fläkt Woods three phase asyncronous motor
Manufacturer: ABB
Lubricationintervalsforverticalmachinesarehalfofthe
abovevalues.
Theamountofgreasestatedinthetableshouldbedoub-
ledifanautomaticregreasingsystemisused.
Thetablevaluesarebasedonthemotorrunningatrated
outputinanambienttemperatureofabout+25°C(approx.
80°Cbearingtemperature).Thevaluesshouldbehalved
for15°Cincreaseinbearingtemperatureandmaybe
doubledfor15°Cdecreaseinambienttemperature.
Higherspeedoperation,eginfrequencyconverterapplica-
tions,orlowerspeedwithheavyloadwillrequireshorter
lubricationintervals.ConsultABBSalesOfficeinsuchcases.
Typicallyadoublingofspeedwillrequireareductionof
lubricationintervalstoapprox.40%ofvaluestabulated
above.
Suitabilityofbearingsforhighspeedoperationmustalsobe
checked.
WARNING!
 Themaximumoperatingtemperature
 ofthegreaseandbearingsmustnotbe
 exceeded.
Lubricants
Whenregreasing,useonlyspecialballbearinggrease
withthefollowingproperties:
- goodqualitygreasewithlithiumcomplexsoapand
 withmineral-orPAO-oil
- baseoilviscosity100-150cSTat40°C
- consistencyNLGIgrade2or3
- temperaturerange-30°C-+120°C,continuously.
Greasewiththecorrectpropertiesisavailablefromall
themajorlubricantmanufacturers.
Thefollowing(orsimilar)highperformancegreasecan
beused
• EssoUnirex N2orN3
• Shell AlbidaEMS2
• SKF  LGHQ3
• Mobil MobilithSHC100
• Klüber KluberplexBEM41-132
• BP  EnergreaseLC2
NOTE!
 Alwaysusehighspeedgreaseforhighspeed
 machinensandsomeothermodels,e.g.M2_355
 and4002-polemachines,wherethespeedfactoris
 higherthan400000(calculatedasDmxnwhere
 Dm=averagebearingdiameter,mm;n=rotational
 speed,rpm).Thefollowing,orsimilar,typesof
 greasecanbeused:
• Kluber AsonicGHY72
• Kluber AsonicHQ72-102
• Shell AlbidaEMS2
• Esso  LT2
• Mobil MobilithSHC100
Thefollowingnormaltypeofgreasecanbeusedifthe
regreasingintervalishalved(thesetypesofgreaseshould
notbeusedwhenbearingtemperatureisabove100°C).
• Esso  Beacon2or3
• Shell AlvaniaRL2orRL3
• SKF  LGMT2or3
• Mobil Mobilux2
• Kluber Centoplex2
• BP  EnergreaseLS2
Ifthemakeofgreaseischangedandcompatibilityis
uncertain,consultABBSalesOffice.
Highlyloadedand/orslowlyrotatingbearingsrequire
EPgrease.
Iftheambienttemperatureisbelow-25°Corabove
+55°C,orbearingtemperatureisabove110°C,consult
ABBSalesOfficeregardingsuitablegrease.
Frame
size
Amount
of grease
g/bearing
3600
r/min
3000
r/min
1800
r/min
1500
r/min
1000
r/min
500-900
r/min
Ball bearings
Lubrication intervals in duty hours
112 10 10000 13000 18000 21000 25000 28000
132 15 9000 11000 17000 19000 23000 26500
160 25 7000 9500 14000 17000 21000 24000
180 30 6000 8000 13500 16000 20000 23000
200 40 4000 6000 11000 13000 17000 21000
225 50 3000 5000 10000 12500 16500 20000
250 60 2500 4000 9000 11500 15000 18000
280 70 2000 3500 8000 10500 14000 17000
315 90 2000 3500 6500 8500 12500 16000
355 120 1200 2000 4200 6000 10000 13000
400 120 1200 2000 4200 6000 10000 13000
Roller bearings
Lubrication intervals in duty hours
160 25 3500 4500 7000 8500 10500 12000
180 30 3000 4000 7000 8000 10000 11500
200 40 2000 3000 5500 6500 8500 10500
225 50 1500 2500 5000 6000 8000 10000
250 60 1300 2000 4500 5700 7500 9000
280 70 1000 1700 4000 5300 7000 8500
315 90 1000 1700 3300 4300 6000 8000
355 120 400 1000 2000 3000 5000 6500
400 120 400 1000 2000 3000 5000 6500
WARNING!
 Greasecancauseskinirritationandeye
 inflammation.Followallsafetyprecau-
 tionsspecifiedbythemanufacturer.

Fläkt Woods 8265 GB 2011.10 6 Specifications are subject to alteration without notice
Installation and maintenance instruction
Fläkt Woods three phase asyncronous motor
Manufacturer: ABB
Spare parts
Whenorderingspareparts,thefulltypedesignationand
productcode,asstatedontheratingplate,mustbe
specified.
Ifthemachineisstampedwithaserialmanufacturing
number,thisshouldalsobegiven.
Environmental requirements
Noise levels
Smallermachineshaveasoundpressurelevelthatnot
exceeding70dB(A).
Thefollowingtableshowscataloguevaluesofsound
pressurelevelsat1mfromthemachinesurface.
Valuesforspecificmachinescanbefoundintherelevant
productcatalogues.Toleranceacc±3dB(A).
Thetablevaluesreferto50Hzsinusoidalsupply
conditions.
For60Hzsinusoidalsupply,add4dB(A)totheabove
values.
Forsoundpressurelevelswithnon-sinusoidalsupplies,
contactABBSalesOffice.
Soundpressurelevelsforallmachinesintheabove
framesizeshavingseparatecoolingsystemsandfor
seriesM2F*/M3F*,M2L*/M3L*,andM2R*/M3R*,are
indicatedinseparatespecificMachineInstructions.
Rewinding
Rewindingshouldalwaysbecarriedoutbyqualified
repairshops.
Smokeventingandotherspecialmotorsshouldnotbe
rewoundwithoutfirstcontactingABBMotors.
Guideline sound pressure level, dB(A)
Frame size 2 pole 4 pole 6 pole 8 pole
132 69 59 61 56
160 69 62 59 59
180 69 62 59 59
200 72 63 63 60
225 74 66 63 63
250 75 67 63 63
280 77 68 66 65
315 80 71 68 72
355 83 80 75 75
400 83 80 - -

Fläkt Woods 8265 GB 2011.10 7 Specifications are subject to alteration without notice
Installation and maintenance instruction
Fläkt Woods three phase asyncronous motor
Manufacturer: ABB
Theseinstructionsdonotcoveralldetailsorvariationsin
equipmentnorprovideforeverypossibleconditiontobe
metinconnectionwithinstallation,operationormain-
tenance.Shouldadditionalinformationrequired,please
contactthenearestABBSalesOffice.
Motor trouble shooting chart
Yourmotorserviceandanytroubleshootingmustbe
handledbyqualifiedpersonswithpropertoolsand
equipment.
TROUBLE CAUSE WHAT TO DO
Motor fails to start Blown fuses Replace fuses with proper type and rating.
Overload trips Check and reset overload in starter.
Improper power supply Check to see that power supplied agrees with motor
name plate and load factor.
Improper line connections Check connections with diagram supplied with motor.
Open circuit in winding or control switch Indicated by humming sound when switch is closed. Check for loose
wiring connection. Also, ensure that all control contacts are closing.
Mechanical failure Check to see if motor and drive turn freely. Check bearings and lubrication.
Short circuited stator Indicated by blown fuses. Motor must be rewound.
Poor stator coil connection Remove end bells, locate with test lamp.
Rotor defective Look for broken bars or end rings.
Motor may be overloaded Reduce load.
Motor stalls One phase may be open Check lines for open phase.
Wrong application Change type or size. Consult manufacturer.
Overload Reduce load.
Low voltage Ensure the name plate voltage is maintained. Check connection.
Open circuit Fuses blown, check overload relay, stator and push buttons.
Motor runs and then
dies down
Power failure Check for loose connections to line, fuses and control.
Motor does not
come up to speed
Not applied properly Consult supplier for proper type.
Voltage too low at motor terminals
because of line drop
Use higher voltage or transformer terminals or reduce load.
Check connections. Check conductors for proper size.
Starting load too high Check load motor is supposes to carry at start.
Broken rotor bars or loose rotor Look for cracks near the rings. A new rotor may be
required, as repairs are usually temporary.
Open primary circuit Locate fault with testing device and repair.
Motor takes too long to
accelerate and/or draws
high amp
Excessive load Reduce load.
Low voltage during start Check for high resistance. Adequate wire size.
Defective squirrel cage rotor Replace with new rotor.
Applied voltage too low Get power company to increase power tap.
Wrong rotation Wrong sequence of phases Reverse connections at motor or at switchboard.
Motor overheats while
running underloaded
Overload Reduce load.
Frame or bracket vents may be clogged
with dirt and prevent proper ventilation
of motor
Open vent holes and check for a continuous stream of air from the motor.
Motor may have one phase open Check to make sure that all leads are well connected.
Grounded coil Locate and repair.
Unbalanced terminal voltage Check for faulty leads, connections and transformers.

Fläkt Woods 8265 GB 2011.10 8 Specifications are subject to alteration without notice
Installation and maintenance instruction
Fläkt Woods three phase asyncronous motor
Manufacturer: ABB
TROUBLE CAUSE WHAT TO DO
Motor vibrates Motor misaligned Realign.
Weak support Strengthen base.
Coupling out of balance Balance coupling.
Driven equipment unbalanced Rebalance driven equipment.
Defective bearings Replace bearings.
Bearings not in line Line up properly.
Balancing weights shifted Rebalance motor.
Contradiction between balancing of rotor
and coupling
(half key – full key)
Rebalance coupling or motor
Polyphase motor running single phase Check for open circuit.
Excessive end play Adjust bearing or add shim.
Scraping noise Fan rubbing air shield Remove interference.
Fan striking insulation Clear fan.
Loose on bedplate Tighten holding bolts.
Noisy operation Airgap not uniform Check and correct bracket fits or bearing.
Rotor unbalance Rebalance.
Hot bearings general Bent or sprung shaft Straighten or replace shaft.
Excessive belt pull Decrease belt tension.
Pulleys too far away Move pulley closer to motor bearing.
Pulley diameter too small Use larger pulleys.
Misalignment Correct by realignment of drive.
Hot bearings ball Insufficient grease Maintain proper quality of grease in bearing.
Deterioration of grease or lubricant
contaminated
Remove old grease, wash bearings thoroughly
in kerosene and replace with new grease.
Excess lubricant Reduce quantity of grease, bearing should not be more than 1/2 filled.
Overloaded bearing Check alignment, side and end thrust.
Broken ball or rough races Replace bearing, first clean housing thoroughly.