印度某MW电厂电气作业指导书33

Thedrytypelowvoltagetransformer第21页共21页InstructionforinstallationandtestThedrytypelowvoltagetransformer1.Relateddocumentationsandstandards1.1.TheChinesestandard(GBJ148-90):Codeforconstructionandacceptanceofthepowertransformer1.2.TheChinesestandard(GB50150-91):Standardforhand-overtestofelectricequipment1.3.TheChinesestandard(DL/T527-95):Operationcodeforpowertransformer1.4.TheChinesestandard(DL408-91):Operationcodeforpowerplantsafety1.5.TheChinesestandard(DL560-95):Operationcodeforelectricsafetyinhighvoltagelaboratory1.6.TheChinesestandard(DL/T5043-95):Designstandardforelectricallaboratoryofthermalpowerplant1.7.TheChinesestandard(SD187-86):Guideprincipleofanalysisandjudgeforsolublegasesintransformeroil1.8.TheChinesestandard(DL/T5161.3-2002):Specificationforconstructionqualitycheckoutandevaluationofelectricequipmentinstallation2.Receiptandstorage2.1.Examinethestateofthedevicesandthematerialsreceivedtocheckthatitcorrespondswithwhatwasordered.2.2.Checkallpackagesforexternalsignsofdamage.2.3.Pleasecheckconditionandqualityofthedevicesandthematerials,andcomparethemwiththepackinglist.2.4.Ifonunpacking,whichmustbecarriedoutcarefully,anydamageorirregularityisnoted,notifythiswithindefiniteperiodofreceiptofthegoods,notificationmustindicatetheshippingnotenumber.2.5.Ifthedevicesistobestoredforevenshortperiodsbeforebeingputintoservice,afterreceiptitisadvisabletoputitbackintoitsrelativecontainerandcoveritwithawaterprooftarpaulin.Useadryanddust-freeambientforstoragewithoutanyaggressivechemicalagents.Placethedeviceandanyfixedpartonahorizontalsurfacenotindirectcontactwiththefloor,butonasuitablesupport.2.6.Selectalocationforthedeviceinaclean,dry,vibration-freeareawithmoderatetemperature.2.7.Withregardtolifting,followtheseinstructions:thedevicesmustbeplacedonasturdysurfaceandpreferablyliftedusinganappropriateliftingforktruck.Theuseofropesis,however,permitted:inthiscasetheliftingropesmustbehookedfirmly.3.Installation3.1Sequencefordrytypelowvoltagetransformerinstallation:Installationofthefoundationchannelsteels;Transportandstoretransformersatsite;Visualcheck;Checkofthetransformerbodies;Positionthetransformers;InstallationofthesupportsonHVandLVsides;Installationofthebus-barinsulators;Installationofthebus-bars;Installationoftheaccessories;Earth.3.2.Checkassoonasthetransformerisdeliveredtothesite,checkwhetherthetypeandspecificationsaccordwiththedesign,thencheckwiththelistfilewhethertechnicaldocument,productandauxiliariesarecomplete.3.3.Transportationandstorageofthetransformeratsite.3.3.1.Whenliftingupthetransformer,thefourliftingearsonthetankoftransformershallbeusedtogether,andatthistimetheincludedanglebetweenslingropeandtheplumbshallbenomorethan30°.3.3.2.Checktheliftingropestomakesureitperfect.3.3.3.Duringthetransportation,thetransformershallhaveaninclinationofanglenomorethan15°.3.4.Positionthetransformers.3.4.1.Checktheembeddedfoundationrailaccordingtothedrawings.Itshallbestraight,smoothandthehorizontaldeviationshallbenomorethan5mm.3.4.2.Drawoutthehorizontalandverticalcenterlinesontransformerfoundation.3.4.3.Positionthetransformerandadjusttheposition.Fixthetransformersoleplatetothefoundationrailfirmly.3.4.4.Setupthetransformerwithdragging,checkwhetherthehoistchainisqualifiedandtheanchorisrationalandfirm.3.5.Checkthetransformerbody3.5.1.Visuallyinspectthetransformers.HVandLVbushingshallhavenocrack,andauxiliariesshallbecompleteandingoodcondition.3.5.2.Tightenallboltsandtapes.3.5.3.Theironcoreshouldbeperfectandwithoutdamage.Insulationoftheironcoretogroundshouldbegoodafterdisconnectouterearthedwire.3.5.4.Thewindingsandtheoutletsshouldbeperfectandwithoutdamage.Connectionbetweentheoutletsandthebushingsshouldbecorrectandsolid.3.5.5.Cleanthetransformerbodywithqualifiedbrushaftercheck.3.6.Assembleandinstallthetransformersupport.3.6.1.ThetransformersupportonsidesofHVandLVshallbewellmadeinthefactorythenonlyneedtoassembleandinstallatsite.3.6.2.AssembleandinstallsupportsonsidesofHVandLV.Dependinguponthedrawings,weldthebracketforfixingtheHVcableheadtotheembeddedparts..AssembletheHVbusbartrussaccordingtothedrawings.Accordingtothesizeofscrewofinsulatorsupportbybusbarmakethreeholesonit.Thenweldthetrusstotheembeddedparts..Fixthebus-supportinginsulatorsontothebustruss.3.6.3.AssembleandinstalltheLVsidetrussofthetransformer..Installthetransformerconnectingboxonthewallaccordingtothedrawings..AssembletheLVsidetrussofthebusaccordingtothedrawings.Makeholesfortheinsulators,andthenfixthetrussonthewall..Fixingtheinsulatorontothetruss.3.6.4.Theentiretrussshallbeweldedfirmlyandbepainted.3.7.Makeupthetransformerbus.3.7.1.Thebusfaceshallbesmooth,clearandneatwithoutanyslightcrackle,wrinkle,andforeignmatterandappearnodeformationandtwisting.3.7.2.Whenmakeupthebus,itshallhavethecoldbending,andnotpermittedthehotbending.3.7.3.Whenbendthebus,thedistancebetweenthebendstartpointandthesupportingbusboard’sedgeofthenearestinsulatorshallnotbemorethanaquartertimesofwhichbetweenthetwosupportingpointsofthebus,andnolessthan50mm.Thedistancebetweenbusbendstartingpointandthebusjointpositionshallbenolessthan50mm.Thebusshallreducetheright-anglebend.Alsothereshallbenoappearanceofslightcracklesandtheobviouswrinkles.3.7.4.Minimumcurvatureradiusshallaccordwiththefollowingdemands:.Whenhavethehorizontalbending,forthecopperandsteelbusof125×10andbelowitshallbenolessthan2timesofthebusthickness..Whenhavetheverticalbends,forthecopperbusof125×10andbelowitshallbenolessthan1.5timesofthebuswidth,forthesteelbusitshallbenolessthanthebuswidth..Thedegreeofcurvaturemulti-pieceofmanybusbarsshallbeidentical.3.7.5.Whenusingtheboltstofixthebusjoint,thedistancebetweentheconnectingpointandthesupportinginsulator’ssupportingboard’sedgeshallbenolessthan50mmandthedistancebetweentheupperbusendandthelowerone’shorizontal-bendingstartingpointshallbenolessthan50mm.3.7.6.Whenturnthebus90degree,thelengthoftheturningpartshallbe2.5~5timesofthebuswidth.3.7.7.Thediameterofthebusscrewholesshallbelarger1mmthanthatofthebolts;thescrewholesshallbeverticalandnoslanting,andthedeviationofdistancebetweencentersofthetwoscrewholesshallbe±0.5mm.3.7.8.Theprocessofbusinterfaceshallbeleveledoffwithoutoxidizedfilm.Thereductionoftheprocessedsectionshallnotbemorethan3%oftheoriginalone.3.7.9.Interfacesofthebusandthebusandtheconnectingterminalswiththeboltsshallaccordwiththefollowingrequirements:.Maintaincleannessafterprocessedthebusinterfaceandapplywithelectriccompoundgrease..Whenplacethebusbarhorizontally,theboltsshallpassthroughfrombottomuptotop.Inothercases,thenutsshallbeplacedatthemaintenancesideandextend2~3threadsoftheboltsfromthenuts..Thetwooutsidesofallbusbars,theboltspassthroughwhich,shallhavethewashers,thenetdistancebetweentwoneighborhoodwashersshallbemorethan3mm,andthereshallbethespringwashersorlocknutsatthesidesofthenuts..Theboltsshallbeuniformlystressed,andtheconnectingterminalofthewiringshallnotbeboreextrastresses..Theinterfaceofbusshallbeconnectedtightly,usingthetorquespannertofirmtheconnectionbolts,andthevaluesoftorqueshallbe17.7~22.6NmforM10,31.4~39.2NmforM12,51.0~60.8NmforM14and78.5~98.1NmforM16bolts..Whenthesteelbusjoinwiththecopperorthealuminumterminal,thesteeljointfaceshallbedaubedwithtin.Ifthecopperjoinedtogetheritalsoisdaubedwithtin.Whenjointhecopperwiththealuminum,thecopperconductorshallbedaubedwithtinorusingthecopper-aluminumtransitionboardandthecopperendshallbedaubedwithtin.3.7.10.Whenbus-barsarefixedonthepillarinsulators,itshallconformtofollowingrequirements:.Fixturesonthebus-barsshallbefittedneatlyandfirmlyonthepillarinsulators,fromwhichnoextrastressshallbesubjecttothebus-bars..FixinghardwareorsupportinghardwareonACbus-barsshallnotformaclosemagneticloop..Whenthebus-barsarearrangedhorizontally,aclearanceof1~1.5mmshallbekeptbetweentheupperplatesofsupportingclipsandthebus-bars..Deadpointonthebus-barsfixedtothepillarinsulatorsshallbeoneoneachsection,itissituatedatmiddleofwholelengthorbetweentwoexpansionjoints..Nosharpcornerandburrshallappearonthebus-barfixtures.3.7.11.TheshadeofexteriorsurfacefinishwillbelightgreyISshade#631forindoorandbattleshipgreyISshade#632foroutdoor.3.8.Installationoftheaccessories3.9.Grounding3.9.1.Connectthefoundationrailwiththemaingroundinggridattwopointsusingsoftcopperstrandedcables.3.9.2.Connectthetransformershelltothemaingroundnetwithcoppertwistedcords.3.9.3.ConnectthetransformerHVandLVbrackets,wringboxtothemaingroundnetatonepointwithcoppertwistedcords.3.10.Allsteelsurfacesshallbethoroughlycleanedbysandblastingand/orchemicalagents,asrequired,toproduceasmoothsurfacefreeofscales,greaseandrust.Theexternalsurfaces,aftercleaning,shallbegivenacoatofhighqualityredoxideoryellowchromateprimerfollowedbyfillercoats.ThetransformershallbefinishedwithtwocoatssyntheticenamelpaintbattleshipgreyasperISshade#632.Thepaintsshallbecarefullyselectedtowithstandtropicalheat,painetc.Thepaintshallnotscaleofforcrinkleorremovedbyabrasionduetonormalhandling.3.11.Qualitystandardsinstallingthedrytypelowvoltagetransformersareasshownintable3.11.Table3.11.:InstallationofthedrytypelowvoltagetransformersItemofexaminationPropertyQualitystandardsMethodsandtoolsforexaminationExaminationoftheequipmentsThecasingsandtheaccessoriesDataplatesandmarksofthecircuitdiagramsCompleteandclearInspectionListtheaccessoriesCompleteCheckdependontheaccessorylistsAppearanceoftheinsulatorsSmooth,withoutcrackInspectionExaminationoftheironcoresAppearanceWithoutdamageanddeformationInspectionChecktighteningclampersoftheironcoresTight,withoutlooseCheckbyawrenchInsulationresistancesoftheironcoresMainHighinsulationresistancesCheckameg-ohm-meterafteropentheearthsheetsbetweentheironcoresandtheclampersEarthofironcoresMainOnepointInspectionExaminationofthewindingsCheckwiringconnectionofthewindingsMainSolidandcorrectPullExaminationofsurfacesWithoutcrackandtracebecausedischargeInspectionInsulationresistanceMainHighinsulationresistanceChecktestreportsOutletsInsulationlayersWithoutdamageandcrackInspectionAppearanceofthenakedconductorsMainWithoutfragmentandspewIntervalsbetweenthenakedconductorsofdifferentphasesandtogroundMainInaccordancewithrelativecodesCheckdependontherelativecodesAnti-loosefixturesMainCompleteandperfectPullBenchesofthelead-wiresSolid,withoutdamageInstallationofthebodiesandtheaccessoriesFixtureofthebodiesSolidandreliableCheckbyawrenchTemperaturecontroldevicesMainReliableoperation,correctindicationPullandcommissioningFansystemFirmandcorrectforrotationdirectionPhasecolormarksCompleteandcorrectInspectionEarthEarthofthecasingsSolidandconductivePullandconductanceexaminationEarthofthebodiesEarthofthetemperaturecontroldevicesReliableandconductiveearthwithflexibleconductorsInspectionandconductanceexaminationEarthofthefansEarthofthedoors3.12.Examinationrecordofthetransformerisasshownintable3.12.Table3.12.:ExaminationrecordofthetransformerProjectnameTypeRatedcapacityRatedvoltageRatedcurrentShortcircuitimpedanceWiringmannerCoolmannerManufactureManufacturingnumberManufacturingdateExaminationdateAmbienttemperatureRelativehumidityExaminationmannerExaminationitemsResultsRemarkDismantletemporarysupportsWithoutdeformationofthebodiesTightboltsLockingmeasureoftheboltsInsulationboltsWithoutdeformationoftheironcoresInsulationpartsInsulationoftheironcorestogroundNumberofearthedpointsoftheironcoresInsulationbetweentheironcoresandscrewrodsoftheironyokesInsulationbetweentheironyokesandtheclampsInsulationbetweenthescrewrodsandtheclampsInsulationbetweentheironyokesanditssteeltapesInsulationoftheironcorescreensLayoutofthewindingsInsulationwrappingofthewindingoutletsNakedpartsoftheoutletsWeldingoftheoutletsInsulationdistancesoftheoutletsConnectionbetweentheoutletsandthebushingsExaminationconclusionAcceptanceopinionSignatureDateConstructiongroupConstructionteamQualitydepartmentSupervisorydepartmentOwner3.13.Installthethermometersperfectly.Qualitystandardsinstallingthethermometersareasshownintable3.13.Table3.13.:InstallationofthethermometersItemofexaminationPropertyQualitystandardsMethodsandtoolsforexaminationCalibrationofthethermometersAccordancewiththemanufacturespecificationCheckthecalibrationreportsMediumsinthesocketsandsealUniformwithoilinthetanks,tightsealInspectionCapillarytubesofthetemperaturebagsWithoutdeformation,curvatureradiusesaremorethan50mm3.14.Qualitystandardscheckingtransformerintegerareasshownintable3.14.Table3.14.:ExaminationofthetransformerintegerItemofexaminationPropertyQualitystandardsMethodsandtoolsforexaminationDataplatesandremarksofcircuitdiagramsDistinctandcompleteInspectionInstallationoftheattachmentsCorrectandsolidAppearanceofthetransformersClean,withoutimpurityonthetopsTemperaturemeasuringdevicesCorrectindicationTestitemsMainQualifiedandcompleteCheckthetestreportsRemarksofthephasecolorsCompleteandcorrectInspectionEarthEarthedoutletbushingsoftheironcoresandclampersSolidandconductivePull,conductanceexaminationSparesecondaryterminalsofthecurrenttransformersEarthreliablyaftershortcircuitBodiesandfoundationsSolidandconductiveConnectionbetweentheleadsandthemainearthednetworksSolidandconductiveSealoftheholesTightInspection4.Test4.1.MeasureDCresistanceofthewindingsandthebushings4.1.1.Carryoutthemeasurementatalltapsofthetapswitch.4.1.2.Differenceofthemeasuredvaluesatthreephasewindingsshouldbelessthan4%ofthemeanvalueofthreephases,anddifferenceofthevaluesmeasuredbetweenthephaselinesshouldbelessthan2%ofthemeanvalueforathreephasetransformerwhichcapacityis1600kVAandbelow.4.1.3.Differenceofthemeasuredvaluesatthreephasewindingsshouldbelessthan2%ofthemeanvalueofthreephases,anddifferenceofthevaluesmeasuredbetweenthephaselinesshouldbelessthan1%ofthemeanvalueforathreephasetransformerwhichcapacityisabove1600kVA.4.1.4.ComparemeasuredDCresistanceswiththatinmanufactureratsametemperature.Differenceofthemcannotexceed2%.4.2.Checkthevoltageratiosofalltaps.Noobviousdifferenceandconsistwithregularityifcomparethevoltageratioswiththenameplatedataofthemanufacturer.Toleranceofthevoltageratioattheratedtappositionforthetransformerwhichvoltagelevelis220kVandaboveis±0.5%.4.3.Checkthevectorgroupofthreephasetransformerandthepolarityofsinglephasetransformerwhichmustconsistwiththemarksonthenameplates.4.4.Measurementofinsulationresistance4.4.1.Methodandsequence.Disconnectallwiresbetweenmeasuredequipmentandotherobjects,thendischargebymeansofearthedwire,theperiodofdischargingshouldexceed1min..Recordthetemperatureoftheequipment..Otherwindingswhicharen’tmeasuredmustbeshortcircuitandgrounded..Voltagelevelsofthemeg-ohm-metersformeasuringinsulationresistanceshouldaccordwiththefollowing:use250Vmeg-ohm-metersforelectricdevicesorcircuitswhichratedvoltagesarebelow100V,500Vmeg-ohm-metersfor100V~500V,1000Vmeg-ohm-metersfor500V~3000V,2500Vmeg-ohm-metersfor3000V~10000V,2500Vor5000Vmeg-ohm-metersfor10000Vandabove..AssumeR60s.orR1min.istheinsulationresistancemeasuredafter60seconds,R15s.isthatafter15seconds,R10min.isthatafter10minutes,thentheinsulationresistanceisR60s.orR1min,theabsorptionratioisR60s./R15s.,andthepolarizationindexisR10min./R1min...Theequipmentshouldbedischargedfullyintothegroundafterthemeasurement.Periodofdischargingshouldexceed2min.4.4.2.Themeasuredinsulationresistancemustexceed70%ofthatmeasuredinthemanufacturer.4.4.3.Measuretheabsorptionratioofthetransformerwhichvoltagelevelis35kVandabove,andthecapacityis4000kVAandabove.Themeasuredabsorptionratiocannotbelessthan1.3ornearthatinthemanufacturerin10~40℃range.4.4.4.Measurethepolarizationindexofthetransformerwhichvoltagelevelis220kVandabove,andthecapacityis120MVAandabove.Themeasuredpolarizationindexshouldbenearthatinthemanufacturer.4.5.Measurethetangentofdielectriclossanglei.e.tgδ(%)ofthewindingsandbushingsforthetransformerwhichvoltagelevelis35kVandaboveandthecapacityis8000kVAandabove.Themeasuredtgδ(%)mustnotexceed130%ofthatinthemanufacturer.4.6.Measurevoltagelevelis35kVandaboveandthecapacityis10000kVAandabove.4.6.1.RatedvoltageandratedcurrentofthetestersmeasuringDCleakagecurrentareasshowninthetable4.6.1.Table4.6.1:RatedvoltageandratedcurrentofthetesterTesteddevicesVoltage(kV)Current(mA)35kVpowercable220510kVandbelowpowercableandotherelectricdevices602Generator1005004.6.2.ReadandrecordtheDCleakagecurrentonhighvoltagebushingsat1min.aftersupplytestvoltage.ThetestvoltagemeasuringtheDCleakagecurrentforanoilimmersedpowertransformermustconsistwiththestandardsisshownasthetable4.6.2.Table4.6.2:TestvoltagestandardsmeasuringDCleakagecurrentRatedvoltageofthewinding(kV)6~1020~3563~330500DCtestvoltage(kV)102040604.6.3.MeasuredDCleakagecurrentforanoilimmersedpowertransformermustnotexceedthereferencevaluesshownasthetable4.6.3.Table4.6.3:ReferenceoftheDCleakagecurrentRatedvoltage(kV)PeakvalueofTestvoltage(kV)Leakagecurrent(μA)atfollowingtemperature(℃)10℃20℃30℃40℃50℃60℃70℃80℃2~351117253955831251786~15102233507711216625035620~352033507411116725040057063~3304033507411116725040057050060203045671001502353304.7.ACvoltagewithstandtest4.7.1.Methodandsequence.CapacityandvoltageoftheACvoltagewithstandtesterareasshowninthetable.Table:CapacityandvoltageofACvoltagewithstandtesterTesteddevicesCapacity(kVA)Voltage(kV)200~600MWgenerators12050/0.38125MWandbelowgenerators5035/0.3835kVelectricdevices50100/0.3820kVelectricdevices870/0.3810kVelectricdevices535/0.38Lowvoltageelectricdevices110/0.3.AssumeUisthetestvoltageinvolt,thenthewaterresistorR1inΩforprotectthetesteddevicemaybecalculatedbyformulaR1=K1U,whereK1=0.5~1Ω/V;thelimitresistorR2inΩforprotectthegapmaybecalculatedbyformulaR2=K2U,whereK2=1Ω/V..Raisethevoltageinno-loadtestafteradjustingthegapforover-voltageprotectioninordertothegapdischargewhenno-loadvoltagereaches1.1U,whereUistestvoltage.Thenraisevoltagetotestvalue,maintainitfor1min.Thegapshouldnotdischarge.Repeatthisoperationthreetimes..Thesettingoftheover-currentprotectionrelayis1.3timesthecapacitivecurrentathighvoltageside..Allnon-testedwindingsandcircuitsmustbeshortcircuitandgroundduringtest.Takeoffallelectronicdevices..Periodfromhalfofthetestvoltagetofullvaluecanbe10~15secondsandthefullvoltageshouldbemaintainedfor1min.Itshouldthenbereducedataratethatwillbringitto1/4valueorlessinnotmorethan15s.4.7.2.CancarryoutACvoltagewithstandtestofthewindingsandthebushingsforthetransformerwhichratedvoltagebelow110kV.4.7.3.Theinsulationresistanceafterthewithstandtestcannotbelowerthan70%ofthatbeforethetest.4.8.Measureinsulationresistanceofthelead-outbushingoftheironcoretogroundwitha2500Vmeg-ohm-meter.Theironcoremustbegroundatonepointbythelead-outbushing.4.9.Calibratethethermometersformeasuringthewindingtemperature.4.10.Checkcontrolandprotectivedevices.4.11.Acceptancetestreportofthetransformersisasshownintable4.11.Table4.11.:AcceptancetestreportofthetransformersProjectnameTransformertypeRatedcapacity(MVA)Ratedvoltage(kV)Ratedcurrent(A)Shortcircuitimpedance(%)WiringmannerCoolmannerTapchangingmannerManufactureManufacturingnumberManufacturingdateTestitemsStandardsMeasuredvaluesResultsRemarkDCresistancesofthewindingsandbushingsPositionsofthetapchangerathighvoltageside1AphaseBphaseCphase2AphaseBphaseCphase3AphaseBphaseCphase4AphaseBphaseCphase5AphaseBphaseCphase6AphaseBphaseCphase7AphaseBphaseCphase8AphaseBphaseCphase9aAphaseBphaseCphase9AphaseBphaseCphase9bAphaseBphaseCphase10AphaseBphaseCphase11AphaseBphaseCphase12AphaseBphaseCphase13AphaseBphaseCphase14AphaseBphaseCphase15AphaseBphaseCphase16AphaseBphaseCphase17AphaseBphaseCphaseAtlowvoltagesideAphaseBphaseCphaseTransformationratioPositionsofthetapchanger1AphaseBphaseCphase2AphaseBphaseCphase3AphaseBphaseCphase4AphaseBphaseCphase5AphaseBphaseCphase6AphaseBphaseCphase7AphaseBphaseCphase8AphaseBphaseCphase9aAphaseBphaseCphase9AphaseBphaseCphase9bAphaseBphaseCphase10AphaseBphaseCphase11AphaseBphaseCphase12AphaseBphaseCphase13AphaseBphaseCphase14AphaseBphaseCphase15AphaseBphaseCphase16AphaseBphaseCphase17AphaseBphaseCphaseVectorgroupofthethreephasetransformersInsulationtestofthewindingsandbushingsHighwindingstootherwindingsandgroundInsulationresistancesAphaseBphaseCphaseAbsorptionratioAphaseBphaseCphasePolarizationindexAphaseBphaseCphaseLowwindingstootherwindingsandgroundInsulationresistancesAphaseBphaseCphaseAbsorptionratioAphaseBphaseCphasePolarizationindexAphaseBphaseCphaseACvoltagewithstandtestHighwindingstootherwindingsandgroundAphaseBphaseCphaseLowwindingstootherwindingsandgroundAphaseBphaseCphaseInsulationresistanceearthwirelead-outbushingoftheironcoreandthefixturestothecasingTestoftheoff-loadtapchangersThermometerAcceptanceopinionSignatureDateConstructiongroupConstructionteamQualitydepartmentSupervisorydepartment5.Puttingintoservice5.1.Generaldescription5.1.1Whenfinishedwiththeoriginalinstallationandallmodifications,conductacompleteoperationtestontheentireinstallationtoverifycompliancewithapplicablestandards.Testingshouldbeconductedbyafactory-trainedtechnicianinthepresenceofarepresentativeofthemanufacturerandtheowner’srepresentative.Followproceduresoutlinedintherelatedstandard.5.1.2.Periodictestingandservicingofthesystem,alldevices,andanyotherassociatedequipmentisessentialtoensureproperandreliableoperation.Testandservicethesystemandthedeviceaccordingtotheschedulesandproceduresoutlinedinthemanufacturer’smanuals.5.1.3.Betweenformalperiodictestingandservicingintervals,therelatedoperationchecksshouldbeperformedfordefiniteperiod,orfrequentlywhenrequiredbytheowner.5.2.Energizethetransformerfor10min.attheratedvoltagefivetimes.Intervalsbetweeneachotherare5min.Operationmustbenormal.5.3.Phasesanditssequenceofthetransformermustbethesameasthatoftheelectricpowernetwork.5.4.Theoperationvoltageofthetransformermaynotbeexceed105%ofthetappingratedvoltageingeneralcase,110%oftheratedvoltageinspecialcase.WhentheoperationcurrentisKtimestheratedcurrent,K≤1,limitthevoltageUasshowninfollowingformula:U(%)=110-5K25.5.Donotchangetheratedcapacityofthetransformerwithanoffloadtapswitchintherangeof±5%oftheratedvoltage.Drop2.5%and5%ofthetransformercapacityiftheno-loadtapswitchistappingat-7.5%and10%.5.6.Monitormaximumphasecurrentwhenthreephaseloadsofthetransformerareunbalanced.Thecurrentoftheneutralwirecannotexceed25%oftheratedcurrentofamediumsizetransformer.5.7.Currentandtemperatureatdifferentloadsmustnotexceedthethresholdshowninthetable5.7.Table5.7:ThethresholdofcurrentandtemperatureLoadclassDistributiontransformer(35kVandbelow)Mediumsizetransformer(100MVAandbelow)Largesizetransformer(above100MVA)NormalperiodicloadLoadcurrent(perunitvalue)Temperatureofhotpointandmetalpartscontactwithinsulationmaterial(℃)140140120LongtimeemergencyperiodicloadLoadcurrent(perunitvalue)Temperatureofhotpointandmetalpartscontactwithinsulationmaterial(℃)150140130ShorttimeemergencyperiodicloadLoadcurrent(perunitvalue)2.01.81.5Temperatureofhotpointandmetalpartscontactwithinsulationmaterial(℃)1601605.8.Commissioningrecordsofthetransformersareasshownintable5.8.Table5.8.:CommissioningrecordsofthetransformersProjectnameTransformertypeRatedcapacity(MVA)Ratedvoltage(kV)Ratedcurrent(A)Shortcircuitimpedance(%)WiringmannerCoolmannerTapchangingmannerManufactureManufacturingnumberManufacturingdateExaminationitemsResultsRemarkExaminationofthedevicesandsystembeforeenergizingNameofthetransformer,cleanappearanceSolidfixtureof