Galanz WP700AP17 User manual

Galanz
MicrowaveOven
MODEL: WP700AP17, WP700AL17-K4
WP800AP20,WP800AL20-K4
Service Manuał

INTRODUCTION
ThisMicrowaveOven Service Manuałisprintedina loose-leafformat.Eachpartisdividedintosectionsrelating
toa generałgroupofcomponentsandeachsectionissubdividedinto various parts describinga particular
componentor service procedurę.
Thesubdividingofthesubjectmatterplusthelooseleafformwillfacilitatetheupdatingofthemanuałasnewor
revised componentsand service procedures arę introduced.
Eachpageofthis service manuałwillbeidentifiedinthe Iower righthandcornerand,asneworrevisedpages
arę published,itwillbeeasytokeepthemanuałupto datę byfollowingthe filing instructionsonthecoverletter.
This Service Manuałisa valuable service tool andcareshouldbetakentokeepitupto datę bypromptand
proper filling ofsubsequentpagesasthey arę issued.
CONTENTS
SAFETYPRECAUTIONS2
1THEHEATINGPRINCIPLEOFMICROWAVE3
2THE STRUCTURE AND WORKING PRINCIPLE OF MICROWWAVE OVEN4
2.1 HIGH VOLTAGERECTIFYINGCIRCUIT.4
2.2MICROWAVEGENERATER5
2.3COOLINGSYSTEM5
2.4ELECTRICCONTROLSYSTEM5
3TYPICALCIRCUITANALYASISOFMICROWAVEOVEN8
4 HOWTO ASSEMBLEANDDISASSEMBLEMICROWAVEOVENCOMPONENTS9
4.1THE GABINET 9
THEDOORCOMBINATION10
4.3THECONTROLPANELANDTHEDOORRELEASEMECHANISM11
4.4 THEMAGNETRON 11
4.5THETRANSFORMER12
4.6 THE FANMOTOR12
4.7 THECAPACITOR 13
4.8THEDIODĘ13
4.9 THETURNTABLECOMBINATIOM 14
4.10THEDOORSAFTYINTERLOCKS14
THECONTROLPANEL OF A TYPICAL MICROWAYE OVEN15
5 BREAKDOWN ANALYSIS AND THE MEANSOFOYERHAULING 16
5.1EXAMININGTHEBREAKDOWNCAUSES16
SPOTEXAMININGSTEPSOFTHEMICROWAVEOVEN 16
5.3REPAIRINGMETHODOFSEVERALBREAKDOWN19
5.4THECHARACTERS REOUIREMENTS OF MICROWAYE AFTERITHASBEENREPAIRED20
6CRITICALPARTS SERYICING 21
6.1IMPORTANTTHINGSTODO PRIOR TOCRITICALPARTSSERVICING:21
6.2InterlockAssemblyReplacementandAdjustment21
7COMMONBREAKDOWNOF MICROWAYE OVENANDMEANSOFREPAIRING......22

SAFETY PRECAUTIONS
PRECAUTIONSTOBEOBSERVEDBEFOREANDDURING
SERVICINGTOAVOIDPOSSIBLEEXPOSURETOEXCESSIVE
MICROWAYE ENERGY
A.Donotoperateor allow theoventobeoperatedwiththedooropen.
B. Mąkę thefollowingsafetycheckson all ovenstobe serviced beforeactivatingthemagnetronor
othermicrowavesource,and mąkę repairs as necessary.
(1). Interlockoperation
(2).Properdoorclosing
(3). Sealandsealing surfaces (arcing, wear, andotherdamage).
(4).Damagetoor loosening of hinges andlatches.
(5).Evidenceof dropping orabuse.
C.Beforeturningon microwave powerforany service testorinspection within themicrowave
generating compartments, checkthemagnetron,waveguideortransmission linę, andcavityfor
properalignment,integrity,andconnections.
D.Anydefectiveormisalignedcomponentsinthe interlock, monitor, door seal andmicrowave
generationandtransmissionsystems shall berepaired,replaced,oradjustedbyprocedures
describedinthismanuałbeforetheovenisreleasedtotheowner.
E.A microwave leakagechecktoverifycompliancewiththeFederal performance standardshouldbe
performed oneachovenpriortoreleasetotheowner.
THISMANUAŁ,ASWELLASTHEINFORMATIONCONTAINEDIN IT, ISTOBEUSEDONLYBY AŃ
AUTHORIZEDSERVICE TECHNICIAN FAMILIARWITHANDKNOWLEDGEABLEOFPROPER
SAFETYAND SERVICING PROCEDURESAND POSSESSING HIGH OUALITY TEST EOUIPMENT
ASSOCIATEDWITH MICROWAVEAND ELECTRICALAPPLIANCEREPAIR.
ALL INDMDUALS WHOATTEMPTREPAIRSBYIMPROPERMEANSORADJUSTMENTSUBJECT
THEMSELYES ANDOTHERSTOTHE RISK OFSERIOUSORFATALINJURY

1THEHEATINGPRINCIPLEOF MICROWAYE
Microwaveisonekindofradiowavewhose wavelength is very short, frequencyis very high.Therefore,itis
called ultrahigh frequencyelectromagneticwave.Microwavecanheatfoodmainlyresultinthe mutual affect of
thefoodinthemicrowave field andthemicrowave field itself.
Undertheaffectofmicrowavefield,thethermal effect mechanismproduced from themutualaffectofthe
microwaveandthefoodincludes two aspects.OneisDielectric loss ofpolarmolecule;theotheris conductive
loss ofion.
Usually,foodisconstitutedoforganism(plantandanimal).Theorganismisformedby all kindsofpolarwater
molecule, polarproteinmolecule,andall sorts ofsaltion.Thecenterofgravityofthepositiveandnegativecharge
inthemoleculeisnotcoinciding.Innormalcondition,themoleculeisinirregularorderduetoitsthermalaction,
thus thefooddonotappearpolarity. (FIG. 1-la). Undertheactionofouterelectric field, thepositiveendofthe
polarmoleculetrendtothenegativeelectricfield,thenegativeendofpolarmoleculetrendtothepositiveelectric
field,andsomewhatarrangeinorderthroughthedirectionoftheelectricfield(FIG. 1-1 c).Thisphenomenon
usuallyiscalled "TORGUE POLARITY".Whentheouterelectricfield apply fortheopposite polarity, thepolar
moleculethenarrangeanoppositedirectionorderaccordingly(FIG. 1-1 b). If thedirectionoftheouterelectricfield
changedrepeatedly,thepolarmolecule would repeatedlyswayaccordingly.Duringtheswaying,itis
understandingthatthepolarmoleculewouldproduceheatduetosomewhatsimilarfriction among them. When
theelectricfieldisappliedforultrahighfrequentmicrowavefieldfromtheoutside,itsdirectionwouldchangetens
billion times persecond,sodothemolecule.Thiskindofmoleculeswayingproducingsimilarfrictionalheatfrom
the interference andbłockoftheactionstrengthamongthemolecule,andchangedtomicroscopicmicrowave
heating. Microwave heatingnot only concernedthenaturęofthematter itself, but also closelyconnectedwiththe
electricstrengthandfrequency.WhenthefrequencyisIow,themoleculeswaying ratę andtheacutedegreeof
themutualfrictionamongthemoleculeisIow,andwouldproducemuchheat.Whenthefrequencyistoohigh,as
theswingofthepolarmoleculeiswithrotating inertia, it madę theswingdonotin linę withthechangingrhythm
oftheelectricfieldbecauseofthefriction drąg, thus,actually Iowed thepolarmoleculeswayingspeed.The
frictiondraggingdegreeisconcerningaboutthemagnelectricwavefrequency,polarmoleculeshape,andthe
matter's stickydegree.Todifferent matter's molecule,thereisdifferentspecialfrequency żonę. Thoseabsorbing
microwaveenergyfromthis żonę arę mostcapabletoturnmicrowaveenergytoheatenergy.
(a)
(b) (c)
Fig. 1-1
Apart fromtheabovesaid action, thereisanotheractionwhichiselectricionundertheactionof microwave field,
actfiercelyaccompaniedwiththeaccelerationofelectricfield.Thepositiveiontransfertothenegativepolarityof
thefield while thenegativeiondoesopposite.Accompanyingwiththechangingelectricfield,theelectricion
hangingaccordingly.Duringthetransferring,heatproducedwiththecrashamongtheion.Thiskindofaction
takesthe main effecttothosemicrowavesheatingofhighsaltmolecule.
Nomatteritisthepolarmoleculeswayingortheiontransferring,theyboth arę turningthemicrowaveenergy
whichtheheatingmattergotfromthemicrowavefieldtoheatenergy.Fromtheanalysisoftheory,wecandraw
such a conclusionthatthepowerwhicha unitofvolumematterabsorbedfromthemicrowavefieldasthe
followingformuła:

Pa=KE fErtg 5
PaStandsforthepowertheheated matter adsorbed from themicrowave field.
KStandsfora constant
EStandsforthe microwave frequency.
fStandsforthemicrowave frequency.
tg6 Standsfor loss angle tangentoftheheatedmatter.
ErStandsforrelativedielectricconstantoftheheatedmatter.
High Voltage Rectifier
220V
r
2THESTRUCTUREAND WORKING PRINCIPLE OF MICROWWAVE
QVEN.
Microwaveovencanbeclassifiedto many kinds
accordingto various construction, volumeandcontrol
function.Butanyhow,the main electric parts arę all
composedofhighvoltage rectification, coolingsystem.
Microwavegenerator,electriccontrolsystemandheating
chamber (FIG.2-1). Its workingprocess arę asfollows:
220Vpowerfrequencyvoltagetransferredtotherectifier
throughelectriccontrol system, andthenbechangedto
4000Vdirectvolt-agebytherectifier,andbethen
transferredtothemicrowavegenerator,thegenerator
starsworkingtotransferthemicrowaveenergytothe
heatingchamberforheatingfoodthroughwaveguide
tubę. Atthesametime,theelectriccontrolsystemsetoff
thecoolingsystemto cool theworkingrectifierandthe
microwavegeneratortokeeptheovenworkingsteadily
froma toohightemperaturę. If somethingwrongwiththe
coolingsystemcausethetemperaturętoohigh,thecontrolsystemwouldcutoffthepowerautomaticallyto
preventmicrowavegeneratorbeingdamagedformthehightemperaturę. Nów, we'd like tointroducetheworking
principleofeach part ofthewidelyusedmodel,mechanicalcontrolandtouchcontrolmicrowaveoven.
2,1HIGH VOLTAGE RECIIFYING CIRCUIT.
Atpresent, home usemicrowaveovenadoptthishighvoltage rectifying circuitasshownatdiagram2-2.The
circuitisa singlephase,semi-wave,doublevoltagerectifyingcircuit.Thecircuithas only a highvoltagecapacitor,
ahighvoltagediodę,a magneticleakagetransformerbesidesthemagnetron,is very simple.
Theworkingprincipleofthecircuit:220Vpowerboostedthroughthetransformer,outputabout2000Valternating
highvoltagecurrentwhenthehighvoltagewindingisatthepositivehalf-circle,thehighvoltagewindingisatthe
negative half-circle, thediodęiscutoffandthemagnetronisconducted.The electricity chargedatthepositive
half-circleofthecapacitorisseriesconnectedwiththepositivephaseofthewinding voltage, andgota doubled,
about4000Vdirecthighvoltage,thentransferredto between thecathodeandtheanodęofthemagnetron.
Electric Control
220V
Fig. 2-2
Fig. 2-3