《水力发电厂高压电气设备选择及布置设计规范》（NB-T 10345-2019）英文版

ICS27.140

P59NB

ENERGYSECTORSTANDARD

OFTHEPEOPLE'SREPUBLICOFCHINA

中华人民共和国能源行业标准

PNB/T10345-2019

ReplaceDL/T5396-2007

_______________________________________________________________________

CodeforDesignofHighVoltageElectricalEquipmentSelectionand

ArrangementforHydropowerPlants

水力发电厂高压电气设备选择及布置

设计规范

（征求意见稿）

IssuedonDec30,2019ImplementedonJuly1,2020

IssuedbyNationalEnergyAdministrationofthePeople'sRepublicofChina

I

Introduction

ThisEnglishversionisoneoftheChina'senergyindustrystandardseriesinEnglish.Its

translationwasorganizedbyChinaRenewableEnergyEngineeringInstituteauthorizedby

NationalEnergyAdministrationofthePeople'sRepublicofChinaincompliancewith

relevantproceduresandstipulations.ThisEnglishversionwasissuedbyNationalEnergy

AdministrationofthePeople’sRepublicofChinaintheAnnouncement[202x]No.xxdated

xxxx,202x.

ThisversionwastranslatedfromtheChineseStandardNB/T10345－2019,CodeforDesign

ofHighVoltageElectricalEquipmentSelectionandArrangementforHydropowerPlants.The

copyrightisreservedbyNationalEnergyAdministrationofthePeople’sRepublicofChina.

Intheeventofanydiscrepancyintheimplementation,theChineseversionshallprevail.

Manythanksgotothestafffromrelevantstandarddevelopmentorganizationsandthosewho

haveprovidedgenerousassistanceinthetranslationandreviewprocess.

ForfurtherimprovementoftheEnglishversion,allcommentsandsuggestionsarewelcome

andshouldbeaddressedto:

ChinaRenewableEnergyEngineeringInstitute

No.2Beixiaojie,Liupukang,XichengDistrict,Beijing100120,China

Website:

Translatingorganization:

POWERCHINAChengduEngineeringCorporationLimited

Translatingstaff:

Reviewpanelmembers:

NationalEnergyAdministrationofthePeople’sRepublicofChina

-

翻译出版说明

本译本为国家能源局委托水电水利规划设计总院按照有关程序和规定，统一

组织翻译的能源行业标准英文版系列译本之一。202x年xx月xx日，国家能源

局以202x年第x号公告予以公布。

本译本是根据中国水利水电出版社出版的《水力发电厂高压电气设备选择及

布置设计规范》NB／T10345-2019翻译的，著作权归国家能源局所有。在使用

过程中，如出现异议，以中文版为准。

本译本在翻译和审核过程中，本标准编制单位及编制组有关成员给予了积极

协助。

为不断提高本译本的质量，欢迎使用者提出意见和建议，并反馈给水电水利

规划设计总院。

地址：北京市西城区六铺炕北小街2号

邮编：100120

网址：

本译本翻译单位：中国电建集团成都勘测设计研究院有限公司

本译本翻译人员：

本译本审核人员：

国家能源局

-

AnnouncementofNationalEnergyAdministration

ofthePeople'sRepublicofChina

[2019]No.8

152energysectorstandards(attachment1)suchasthe"Codeforoperatingandoverhauling

ofexcitationsystemofsmallhydropowerunits",theEnglishversionof39energysector

standards(attachment2)suchasthe"CodeforSafeandCivilizedConstructionofOnshore

WindPowerProjects"areissuedbyNationalEnergyAdministrationofthePeople’sRepublic

ofChinaandapproval.

Attachment:1.DirectoryofSectorStandards

2.DirectoryofEnglishversionofSectorStandards

NationalEnergyAdministrationofthePeople’sRepublicofChina

December30,2019

Attachment1:

DirectoryofSectorStandards

ReplacedAdopted

SerialStandardApprovalImplement

Titlestandardinternational

numberNo.dateationdate

No.standardNo.

CodeforDesignof

HighVoltage

NB/TElectricalEquipment

222019-12-302020-07-01

10345-2019Selectionand

Arrangementfor

HydropowerPlants

…

-

Foreword

AccordingtotherequirementsofDocumentGNKJ[2016]No.238,"NoticeofNational

EnergyAdministrationofthePeople’sRepublicofChinaonReleasingtheFormulation

(revision)PlanoftheEnergySectorStandardsin2016",andafterextensiveinvestigationand

research,summarizationofpracticalexperience,widesolicitationofopinions,thedrafting

grouphasformulatedthiscode.

Themaintechnicalcontentsofthiscodeinclude:basicrequirements,theselectionofhigh

voltageelectricalequipment,thelayoutofhighvoltageelectricalequipment.

Themaintechnicalcontentsrevisedareasfollows:

-Addingtwoterms"assemblytransformer"and"take-overcurrent"

-Addingthecontentsofsolidinsulatedtubularbus-bar,assemblytransformer,auxiliary

powertransformer,electronicvoltagetransformer,electroniccurrenttransformer,insulator,

bushing,linetrap,gas-filledalternating-currentmetal-enclosedswitchgear,highvoltagefuses

andothercontents.

-Revisingapplicationscopeofthiscodefrom"3kVto500kV"to"3kVto750kV".

-Revisingtheformulaofelevationcorrectionforelectricalequipmentexternalinsulator,

classificationofpollutionlevel,andtherequirementsforcreepagedistance.

NationalEnergyAdministrationofthePeople’sRepublicofChinaisinchargeofthe

administrationofthiscode.ChinaRenewableEnergyEngineeringInstitutehasproposedthis

codeandisresponsibleforitsroutinemanagement.EnergySectorStandardizationTechnical

CommitteeonHydropowerElectricalDesignisresponsiblefortheexplanationofthespecific

technicalcontents.Commentsandsuggestionsintheimplementationofthiscodeshouldbe

addressedto:

ChinaRenewableEnergyEngineeringInstitute

No.2Beixiaojie,Liupukang,XichengDistrict,Beijing100120,P.R.China.

Chiefdevelopmentorganization:

POWERCHINAChengduEngineeringCorporationLimited

Participatingdevelopmentorganization:

POWERCHINANorthwestEngineeringCorporationLimited

Chiefdraftingstaff:

WENFengxiangYANGHongHUANGKaiQINYing

ZHAOHuimeiFANGLeiLIYongWANGYaohui

HOUYanshuoSANGZhiqiangZHANGLiZHANGYong

-

JULinSONGLinli

Reviewpanelmembers:

YUQingguiFANGHuiFENGZhenqiuKANGBenxian

WANGJinfuCHENYinqiSHIFengxiangXIAFujun

YANGJianjunSUNFanWANGXiaobingWANGYong

SHAOGuangmingWANGHuajunXIEXiaohuiDUGang

LIShisheng

-

Contents

1GeneralProvisions1

2Terms2

3BasicRequirements3

3.1GeneralRequirements3

3.2Electricalrequirements3

3.3Mechanicalrequirements4

3.4Climaticandenvironmentalrequirements5

4TheSelectionofHighvoltageElectricalEquipment8

4.1Conductor8

4.2MainTransformer13

4.3AuxiliaryPowerTransformer16

4.4GeneratorCircuit-breaker17

4.5Electricbrakeswitch17

4.6HighvoltageCircuitBreaker18

4.7HighvoltageLoad-breakingSwitch18

4.8HighvoltageDisconnectorsandEarthingSwitches19

4.9GasInsulatedMetal-enclosedSwitchgear20

4.10ACMetal-enclosedSwitchgear23

4.11Highvoltagefuses23

4.12Voltagetransformer24

4.13CurrentTransformer26

4.14Shuntreactor28

4.15Current-LimitingReactor29

4.16Generatorneutralgroundingdevices30

4.17Surgearrester32

4.18Bushing34

4.19Insulator34

4.20Linetrap34

5TheLayoutofHighvoltageElectricalEquipment35

5.1TheLayoutofMainElectricalEquipment35

5.2Clearancerequirement40

5.3AccessandFence49

5.4RequirementforBuildingandCivilWork52

ExplanationofWordinginThisCode55

ListofQuotedStandards56

1GeneralProvisions

1.0.1Inordertostandardizetheselectionandarrangementdesignofhighvoltageelectrical

equipmentinhydropowerplants,soastomakeitsafeandreliable,technologicallyadvanced

andeconomicalreasonable.thiscodeisformulated.

1.0.2Thiscodeappliestotheselectionandarrangementdesignofhighvoltageelectrical

equipmentwithnominalvoltagefrom3kVto750kVfornewlybuilt,reconstructedand

expandedhydropowerplants.

1.0.3Inadditiontothiscode,theselectionandarrangementdesignofhigh-voltage

electricalequipmentinhydropowerplantsshallalsocomplywiththecurrentrelevant

standardsofChina.

2Terms

2.0.1incomingline

thelineleadingfrommaintransformertohighvoltageswitchgear.

2.0.2outgoingline

thelineleadingfromhighvoltageswitchgeartohighvoltageoutgoingequipment.

2.0.3connectingline

thelineinhydropowerplantforswitchgearsofdifferentvoltagelevelsleadtoan

interconnectingtransformer,oramongswitchgearsofthesamevoltagelevelbutatdifferent

locations.

2.0.4assemblytransformer

thepowertransformerneededtobedisassembled,transported,andassembledatthe

installationsiteaftervariousfactorytestsduetothelimitationoftransportation.

2.0.5take-overcurrent

thecurrentattheintersectionofthetime-currentcharacteristiccurvesoftwokindsof

overcurrentprotectiondevices.

3BasicRequirements

3.1GeneralRequirements

3.1.1Theselectionandarrangementofhighvoltageelectricalequipmentshallchoosesafe

andreliable,technologicallyadvancedandeconomicalreasonableproducts，Accordingto

thespecificconditionsoftheprojectandlong-termdevelopment.Meanwhilethelayout

schemeshouldbeformulatedaccordingtotherequirementsofclimate,environment,geology,

topography,layout,incomingandoutgoinglinemodeandequipmentmanufacturing,

operation,maintenance,installationandtransportation.Theprincipleofsavinglandand

energy-savingshouldbefollowedtomeettherequirementsofenvironmentalprotection.So

astoachievereasonabledesign,reliableoperation,convenientinstallationandmaintenance.

3.1.2Highvoltageswitchgearof72.5kVandaboveshouldusegasinsulated

metal-enclosedswitchgear(GIS).Alsocanusetheairinsulatedswitchgear(AIS)orhybrid

gasinsulatedmetal-enclosedswitchgear(H-GIS)accordingtospecificengineering

conditions.

3.1.3Intheselectionofincomingline,outgoinglineandconnectinglinetype,themain

electricalwiring,maintransformerlayout,switchstationtypeandlayoutshallbe

comprehensivelyconsidered.

3.2Electricalrequirements

3.2.1Themaximumvoltageofthehighvoltageelectricalequipmentshouldnotbelower

thanthemaximumvoltageofthesysteminitssystem.

3.2.2Thelong-termallowablecurrentofhighvoltageelectricalequipmentshouldnotbe

lessthanthemaximumcontinuousworkingcurrentofthecircuitundervariouspossible

operationmodes;Theoutdoorlayouthighvoltageelectricalequipmentshouldconsiderthe

influenceofsunlightonitscurrentcarryingcapacity.

3.2.3Thecheckofshort-circuitcurrentshallmeetthefollowingrequirements:

1Theshort-circuitcurrentvalueusedtoverifythepeakwithstandandshort-time

withstandofhighvoltageelectricalequipmentandthebreakingcurrentof

circuit-breakershouldbecalculatedaccordingtotheshort-circuitcurrentofthe

powersystemdesignlevelyear；Themainelectricalwiringandoperationmodeused

inthecalculationshallbethenormalwiringandoperationmodethatthemaximum

short-circuitcurrentmayoccur.

2Theshort-circuitmode,short-circuitpointselectionandshort-circuitcurrent

calculationofthemaximumshort-circuitcurrentshallcomplywithrelevant

provisionsofthecurrentindustrystandardNB/T35043GuidelinesforShort-circuit

CurrentCalculationofThree-phaseACSysteminHydropowerProjects.

3Theshort-timewithstandcurrentofhighvoltageelectricalequipmentprotectedby

fusemaynotbechecked,butthepeaktolerancecurrentshouldbechecked;The

short-timewithstandandthepeakwithstandcurrentofthecircuitofvoltage

transformerprotectedbyfusemaynotchecked.

4Thecalculationtimeofthermaleffectofshort-circuitcurrentshallmeetthefollowing

requirements:

1)Exceptcable,thecalculationtimeofthermaleffectofshort-circuitcurrentof

conductorsshouldadoptthesumofthemainprotectionactiontimeandthe

correspondingcircuit-breakerbreaktime；Whenthemainprotectionhasdead

zone,whenthemainprotectionhasdeadzone,thebackupprotectionaction

timethatcanworkondeadzoneshouldbeadopted;

2)Thecalculationtimeofthermaleffectofcableshort-circuitcurrentshould

adoptthesumofbackupprotectionactiontimeandcorrespondingcircuit

breakerbreaktime;forfeedercableconnectedtomotor,thecalculationtimeof

thermaleffectofshort-circuitcurrentcanadoptthesumofthemainprotection

actiontimeandthecorrespondingbreakerbreaktime;

3)Thecalculationtimeofthermaleffectofshort-circuitcurrentofotherelectrical

equipmentsshouldadoptthesumofbackupprotectionactiontimeand

correspondingcircuitbreakerbreaktime.

3.2.4Thefrequencyofhighvoltageelectricalequipmentsshallbedeterminedaccordingto

theratedfrequencyofthesystemandshalladapttotherangeofsystemfrequencyvariation.

3.2.5Theinsulationleveloftheelectricalequipmentsshallcomplywithrelevant

provisionsofthecurrentnationalstandardGB/T311.1InsulationCoordinationPart1:

Definitions,PrinciplesandRules.

3.2.6Thetemperaturerisetestofhighvoltageswitchgearshallcomplywithrelevant

provisionsofthecurrentindustrystandardDL/T593CommonspecificationforHighvoltage

SwitchgearandControlgearStandards.

3.2.7At1.1timesofthemaximumoperatingphasevoltage,electricalequipmentand

fittingsshouldnothavevisiblecoronaatnightsofthesunnydays.Theradiointerference

voltageofelectricalequipmentwithvoltageof110kVandaboveshouldnotbegreaterthan

500μVinsunnydaysoutdoor;Thetestrequirementsshallcomplywithrelevantprovisionsof

thecurrentnationalstandardGB/T11604Testingprocedureofradiointerferencegenerated

byhighvoltageequipment.

3.3Mechanicalrequirements

3.3.1Theequipment,thesupportingstructureanditsfoundationshallwithstandthe

expectedmechanicalstress,normalloadandtheabnormalloadshallbeconsidered,andthe

mechanicalstrengthofthestructureshouldbedeterminedbythemostunfavorableload

combination.Thecombinationofvariousloadsshallmeetthefollowingrequirements.

1Incaseofnormalloadconditions,staticload,tensionload,installationload,iceload,

windload,andshort-termstressandloadduringconstructionandmaintenanceshall

beconsideredforequipment,supportstructureanditsfoundation.

2Incaseofabnormalload,switchoperatingforce,short-circuitforce,unbalanced

tension,thesimultaneousactionofthemaximumaccidentalload,staticloadand

tensionloadintheseismicloadshallbeconsideredfortheequipment,support

structureanditsfoundation.

3.3.2Themaximumforceoftheelectricalequipment’sleadduringnormaloperationand

shortcircuitshouldnotbegreaterthantheallowableloadoftheelectricalequipment

terminal.

3.3.3Theconductor,bushing,insulatorandfittingsofoutdoorswitchgearshallbe

calculatedaccordingtothemeteorologicalconditionsofthepowerstationanddifferentstress

states.Theminimumsafetycoefficientoftheconductorandinsulatorshallnotbelessthan

theprovisionsintable3.3.3.

Table3.3.3Theminimumsafetycoefficientforconductorsandinsulators

categoryUnderlong-termLoadsUndershort-termLoads

Bushing,supportinsulatoranditsfittings2.51.67

Suspensioninsulatoranditsfittings42.5

Incomingline,outgoingline

3.52.5

Flexiblewireandconnectingline.

Otherflexiblewire42.5

Rigidconductor2.01.67

Note:

1Thesafetycoefficientofthesuspensioninsulatorcorrespondstothe1helectromechanicaltestload.If

correspondingtothefailureload,thesafetycoefficientshouldbe5.3and3.3respectively.

2Thesafetycoefficientofhardconductorcorrespondstothefailurestress.Ifthestresscorrespondstothe

yieldpoint,thesafetycoefficientshouldbe1.6and1.4,respectively.

3.4Climaticandenvironmentalrequirements

3.4.1Theselectionofhighvoltageelectricalequipmentshallmeettherequirementsofair

temperature,windspeed,humidity,pollution,altitude,earthquake,icingandotheroperating

conditions.

3.4.2Theselectionofambienttemperatureforhighvoltageelectricalequipmentshould

complywiththeprovisionsoftable3.4.2.

Table3.4.2Theselectionofambienttemperatureforhighvoltageelectricalequipment

(℃)

Ambienttemperature

categoryLocation

maximumtemperatureminimumtemperature

Meanmaximum

Bare

outdoortemperatureofthehottest—

conductors

month

indoordesigntemperaturewith—

ventilation

SF6InsulationequipmentAnnualmaximumTheextrememinimum

temperaturetemperature

otheroutdoorequipmentthemaximumtemperatureAnnualminimum

inoneyeartemperature

electrical

indoorreactorthemaximumexhaust—

equipment

temperatureforventilation

designing

otherindoorlocationdesigntemperaturewith—

ventilation

Notes:

1Theannualmaximumorminimumtemperatureshouldbetheaveragevalueoveryearsofmeasured

annualmaximumorminimumtemperature.

2Themeanmaximumtemperatureofthehottestmonthreferstotheaveragevalueofthemonthlyaverage

valueofthehottestmonthoveryears.

3Ifthereisnoventilationdesigntemperaturedatafortheselectionoftheambienttemperatureofbare

conductorsandotherelectricalequipmentintheroom,theaveragemaximumtemperatureinthehottest

monthplus5℃canbeselected.

3.4.3Whentheambienttemperatureislowerthantheminimumallowabletemperatureof

thehighvoltageelectricalequipment,thehighvoltageelectricalequipmentshouldbe

equippedwithheatingdeviceorthermalinsulationmeasures.

3.4.4Inareaswithserioussnowingandicing,thehighvoltageelectricalequipmentshould

betakenmeasurestopreventaccidentscausedbysnowandice.

3.4.5Forthehighvoltageelectricalequipmentwithambientairtemperaturehigherthan

40℃,thetestvoltageofitsexternalinsulationinthedrystateshouldbemultipliedbythe

temperaturecorrectioncoefficient,whichcanbecalculatedbythefollowingformulas:

K10.0033(T40)

t(3.4.5)

where

Ktisthetemperaturecorrectioncoefficient

Tistheambientairtemperature(℃)

3.4.6Themaximumwindspeedusedintheselectionoftheelectricalequipmentforthe

outdoorswitchgearshallmeetwiththefollowingprovisions:

1For500kVand750kVvoltagelevelofswitchgear,the10minaveragemaximum

windspeed,10mheightabovethegroundandoncein50years,shallbeadopted.

2Forthevoltagelevelof330kVandbelow,the10minaveragemaximumwindspeed,

10mheightabovethegroundandoncein30years,canbeadopted.

3Whentheheightofconductorsandelectricalequipmentismorethan10mabovethe

ground,themaximumwindspeedshouldbecorrectedaccordingtotheinstallation

heightoftheconductorandelectricalequipment.whichcanbemadeaccordingtothe

relevantformulasofthecurrentindustrystandardDL/T5158Technicalcodefor

meteorologicalsurveyinelectricpowerengineering.

4Whenthemaximumwindspeedexceeds34m/s,correspondingmeasuresshallbe

takenforoutdoorswitchgearlayout.

3.4.7Therelativehumidityofthehighvoltageelectricalequipmentshouldmeetthe

followingrequirements:

1Whensettinguptheventilationfacilities,therelativehumidityshouldbeselected

accordingtothedesignforventilation.

2Whennoventilationfacilitiesaresetup,therelativehumidityoftheworking

environmentforhighvoltageelectricalequipmentshouldbetheaveragerelative

humidityofthelocalmonthwiththehighesthumidityinthepowerplant.

3Incaves,undergroundandhumidplaceswithhighhumidity,therelativehumidityof

thehighvoltageelectricalequipmentshouldbetheactualrelativehumidity.

4Withnorelevantinformation,therelativehumidityofthehighvoltageelectrical

equipmentenvironmentcanbe95%.

3.4.8Theseismicdesignofhighvoltageelectricalequipmentshouldcomplywithrelevant

provisionsofthecurrentnationalstandardGB50260Codesforseismicdesignofelectrical

installations.

3.4.9Forelectricalequipmentinstalledatanaltitudehigherthan1000m,whenthetestof

externalinsulationwithstandvoltageisconducted,theactualwithstandvoltageappliedtothe

externalinsulationoftheequipmentshouldbemultipliedbytheelevationcorrectionfactorKa,

Kashouldbecalculatedbythefollowingformulas:

H1000

q()

Ke8150

a（3.4.9）

where

Kaistheelevationcorrectioncoefficient

Histheelevationofequipmentinstallationsite（m）

qisthevalueoftheindexshouldconformtorelevantprovisionsofthecurrent

nationalstandardGB/T311.1Insulationco-ordinationPart1:Principles,

definitionsandrules.

3.4.10Theclassificationofon-sitepollutiongradeandtheuniformcreepagedistanceshould

complywithrelevantprovisionsofthecurrentnationalstandardGB/T26218.1Selectionand

dimensioningofhighvoltageinsulatorsintendedforuseinpollutedconditions--Part1:

Definitions,informationandgeneralprinciples.

4TheSelectionofHighvoltageElectricalEquipment

4.1Conductor

4.1.1Thetypeofconductorshouldbeselectedaccordingtotherequirementsofvoltage

grade,loopcurrent,environmentalconditionsofpowerstation,sitelayout,installationand

maintenance,projectinvestment,etc.

4.1.2Thegeneratorvoltagecircuitbuscanadoptisolatedphaseenclosedbus,common

enclosurebus,solidinsulatedtubularbus-bar,cableandopenbus.Thetypeselectionshould

meetthefollowingrequirements:

1Forthegeneratorvoltagebus,whentheratedcurrentofthecircuitisnomorethan

4000A,commonenclosurebusshouldbeselected,andsolidinsulatedtubularbus-bar

canbeusedwhenthelayoutsiteisnarrow.Whentheratedcurrentofthecircuitis

morethan4000A,thecontinuousenclosuretypeisolated-phasebusshouldbe

selected.Whentheratedcurrentofthecircuitisnomorethan6300A,andthelayout

isnarrow,solidinsulatedtubularbus-barcanalsobeused.

2Themaingeneratorvoltagebusoflightbulbtubularturbineunitscanbecable,

commonenclosurebusorsolidinsulatedtubularbus-bar.

3Thetypeselectionofgeneratorvoltagecircuitbusshouldbeconsidering

convenientlyconnectedwithothergeneratorvoltageequipment.

4Whenthemainbusofthegeneratorvoltagecircuitadoptscable,itisappropriateto

choosethesingle-core,copper-coreXLPEcable.Thevoltagebetweencablecoreand

insulationshieldormetalsheathshouldbe173%oftheworkingphasevoltageofthe

circuit.Othertechnicalrequirementsshouldcomplywithrelevantprovisionsofthe

currentnationalstandardGB50217Standardfordesignofcablesofelectrical

engineering.

5Whenthegeneratorvoltagecircuitadoptsopenbus,openbuscanbeusedfor4000A

andbelow,andtroughbuscanbeusedfrom4000Ato8000A.

6Thegeneratorvoltagebranchcircuitbusshouldbeofthesametypeasthemain

circuitbus.

4.1.3Theconductorsof110kVandaboveHighvoltageswitchgearcanbehighvoltage

cable,gasinsulatedmetal-enclosedtransmissionline(GIL),tubularbus-bar,Flexiblewire,

etc.Inplaceswherethelines,outgoinglines,connectinglinesinoverheadlinesaredifficult

toberealized,highvoltagecablesandGILcanbeusedthroughtechnicalandeconomic

comparison.Thetechnologicalandeconomiccomparisonshouldconsidertheconductor

capacity,civilstructure,operationandmaintenance,investmentandsoon.

4.1.4Theselectionofisolated-phasebusshouldmeetthefollowingrequirements:

1Theselectionoftechnicalparametersofisolated-phasebusshouldbeselected

complywithrelevantprovisionsofthecurrentnationalstandardGB/T8349

Metal-enclosedBus.

2Isolated-phasebusmaybeprovidedwithtemperaturemeasuringdevicesfor

monitoringthetemperatureofconductors,jointsandenclosuresatjointsorother

locationspronetooverheating.

3Theconnectionbetweentheisolated-phasebusandthelightningarrestercabinet,the

voltagetransformercabinetandtheneutralequipmentcabinetshouldbethroughthe

insulatingbushortheseparatortopreventthefaultinthecabinetfromaffectingthe

bus.

4Detach