-
7/13/2015 TypicalLimitingValuesofSubStationEquipments.|ElectricalNotes&Articles
https://electricalnotes.wordpress.com/2011/03/31/typicallimitingvaluesofsubstationequipments/ 1/7
ElectricalNotes&Articles
SharingAbstracts,NotesonvariousElectricalEngineeringTopics.
TypicalLimitingValuesofSubStationEquipments.
MARCH31,2011 12COMMENTS(HTTPS://ELECTRICALNOTES.WORDPRESS.COM/2011/03/31/TYPICALLIMITINGVALUESOFSUBSTATIONEQUIPMENTS/#COMMENTS)
TypicalLimitingValuesofSubStationElectricalEquipments.
1.Transformer/Reactor:
Sr.No. Equipment/testdata Permissiblelimits Reference
A)
Transformeroil
a)BDV
Atthetimeoffirstcharging 600kV(Gap2.5mm)Minimum IS1866
DuringO&M 50kV(Gap2.5mm)Minimum IS1867
b)Moisturecontent IS1868
Atthetimeoffirstcharging 15PPM(Max.) IS1869
DuringO&M 25PPM(Max.) IS1870
c)Resistivityat90degreeC 0.11012OhmCM(Min.) IS1871
d)Acidity 0.2mgKOH/gm(Max.) IS1872
e)IFTat27degreeC 0.018N/M(Min.) IS1873
f)Tandeltaat90degreeC 0.20(Max.) IS1874
g)Flashpoint 126Deg.C(Min.) IS1875
B)Vibrationlevelforreactors 200Microns(PeaktoPeak) IS1876
60Microns(Average) IS1877
C) Tandeltaforbushingat20Deg.C0.007* IEC137
D) Capacitanceforbushing +5%variation IEC138
E) IRvalueforwinding 1000MOhmBy5.0/10.0kVMeggerIEC139
F) Tandeltaforwindingsat20Deg.C0.007* IEEE/C57.12.90.1980
G) Contactresistanceofbushingterminalconnectors10M.Ohm/Connector NGC.UK
Recommendations
H) TurretNeutralCTratioerrors 39 IS2705
2.CircuitBreakers
-
7/13/2015 TypicalLimitingValuesofSubStationEquipments.|ElectricalNotes&Articles
https://electricalnotes.wordpress.com/2011/03/31/typicallimitingvaluesofsubstationequipments/ 2/7
Sr.No. Equipment/testdata Permissiblelimits Reference
A) DewpointofSF6gas DewpointvaluesasperAnnexureII
B) Dewpointofoperatingair 45Deg.CatATM.Pressure
C)
CBOperatingtimings 400kV220KV
a)Closingtime(Max.) 150MS200MS
b)Triptime(Max.) 25MS35MS
c)Close/triptime,Polediscrepancy
PhasetoPhase(Max.) 3.33MS3.33MS
Breaktobreak(Max.)ofsamephase 2.5MS2.5MS
D)
PIRtime
BHELmake 1216MSManufacturersRecommendations
ABBmake 812MSManufacturersRecommendations
NGEFmake 812MSManufacturersRecommendations
M&Gmake 812MSManufacturersRecommendations
TELKmake 812MSManufacturersRecommendations
ABBmake(HVDC) 812MSManufacturersRecommendations
E)PIRopeningtimepriortoopeningofmaincontacts(ABB,CGL,NGEFmakeCBs) 5MS(Min.)atratedpressure
ManufacturersRecommendations
F)Pirandmaincontactsoverlaptime[BHEL,M&G,ABB(imported)makeCBs] 6MS(Min.)atratedpressure
ManufacturersRecommendations
G) Tandeltaofgradingcapacitors 0.007at20Deg.C
H) CapacitanceofgradingcapacitorsWithin+10%/5%oftheratedvalue IEC359
I) ContactresistanceofCB 150M.Ohm
J) ContactresistanceofCBterminalconnector 10M.OhmperconnectorNGC,UKrecommendations
K)
IRvalue:
1.Phaseearth 1000MOhm(Min.)by5.0/10.0kVMegger
2.Acrossopencontacts 1000MOhm(Min.)by5.0/10.0kVMegger
3.Controlcables 50MOhm(Min.)by0.5kVMegger
L)
Pressureswitchsettings
SF6gaspressureswitches Within+0.1Barofsetvalue
Operatingairpr.Switches Within+0.1Barofsetvalue
Operatingoilpr.Switches Within+0.1Barofsetvalue
M)
BDVofoilusedforMOCB
Atthetimeoffilling 40kVat2.5mmGap(Min.) Mfgs.Recommendation
DuringO&M 20kVat2.5mmGap.(Min.) Mfgs.Recommendation
-
7/13/2015 TypicalLimitingValuesofSubStationEquipments.|ElectricalNotes&Articles
https://electricalnotes.wordpress.com/2011/03/31/typicallimitingvaluesofsubstationequipments/ 3/7
3.CurrentTransformer
Sr.No. Equipment/testdata Permissiblelimits Reference
A)
IRvalue
1.Primaryearth 1000MOhm(Min.)by5.0/10.0kVMegger
2.Secondaryearth 50MOhm(Min.)by0.5kVMegger
3.Controlcables 50MOhm(Min.)by0.5kVMegger
B) Tandeltavalue 0.007*at20Deg.C
C) TerminalConnector 10MOhmperconnectorNGC,UKRecommendations
D) CTratioerrors +3%Protectioncores IS2705
D) CTratioerrors +1%Meteringcores IS2706
4.CapacitiveVoltage
Sr.No. Equipment/testdata Permissiblelimits Reference
A) TanDelta 0.007*at20Deg.C
B) Capacitance Within+10%/5%oftheratedvalue IEC358
C Contactresistanceofterminalconnector 10MOhmperconnectorNGC,UKRecommendations
D)
IRValue IRValue
1.Primaryearth 1000MOhm(Min.)by5.0/10.0kVMegger
2.Secondaryearth 50MOhm(Min.)by0.5kVMegger
3.Controlcables 50MOhm(Min.)by0.5kVMegger
E)
EMUtankoilparameters EMUtankoilparameters
a)BDV(Min.) 30kV(Gap.2.5mm) IS1866
b)Moisturecontent(Max.) 35ppm do
c)Resistivityat90Deg.C 0.11012Ohm.CM do
d)Acidity 0.5mgkOH/gm(Max.) do
e)IFTat27Deg.C 0.018N/M(Min.) do
f)Tandeltaat90Deg.C 1.0Max. do
g)Flashpoint 125Deg.C(Min.) do
F) CVTvoltageratioerrors +5%protectioncores IEEE/C93.1.1990
F) CVTvoltageratioerrors +0.5%meteringcores IEC186
5.Isolators
Sr.No. Equipment/testdata Permissiblelimits Reference
A) Contactresistance 300MOhm.(Max.)
-
7/13/2015 TypicalLimitingValuesofSubStationEquipments.|ElectricalNotes&Articles
https://electricalnotes.wordpress.com/2011/03/31/typicallimitingvaluesofsubstationequipments/ 4/7
B) Contactresistanceofterminalconnector 10MOhmperconnector
NGC,UKRecommendations
C)
IRvalue
1.Phaseearth 1000MOhm(Min.)by5.0/10.0kVMeggerNGC,UKRecommendations
2.Acrossopencontacts 1000MOhm(Min.)by5.0/10.0kVMeggerNGC,UKRecommendations
3.Controlcables 50MOhm(Min.)by0.5kVMegger
6.SurgeArrester
Sr.No. Equipment/testdata Permissiblelimits Reference
A) Leakagecurrent 500MAmp.(Resistive) Hitachi,JapanRecom.
B) IRvalue 1000MOhm.(Min.) Hitachi,JapanRecom.
7.Miscellaneous
Sr.No. Equipment/testdata Permissiblelimits Reference
A) Stationearthresistance 1.0Ohm(Max.)
B)
Thermovisionscanning
Temp.upto15Deg.C(aboveambient) Normal
Temp.above1550Deg.C(aboveambient) Alert
Temp.above50Deg.C(aboveambient) Tobeimmediatelyattended
C) TerminalconnectorsContactresistance 10MOhmperconnectorHGC,UKRecommendations
D)
IRvalues
1.Allelectricalmotors 50MOhm(Min.)by0.5kVMegger
2.Controlcables 50MOhm(Min)by0.5kVMegger
3.Lt.Transformers 100M.Ohm(Min.)byMegger
4.Lt.Switchgears 100MOhm(Min.)by0.5kVMegger
8.Batteries
Sr.No. Equipment/testdata Permissiblelimits Reference
A) Terminalconnectorresistance 10MOhm+20% ANSI/IEEE4501989
B) Specificgravity 1200+5GM/Lat27Deg.C
TemperatureCorrectionFactorforTanDeltaMeasurement
Sr.No. OiltemperatureDeg.C Correctionfactor(K)
-
7/13/2015 TypicalLimitingValuesofSubStationEquipments.|ElectricalNotes&Articles
https://electricalnotes.wordpress.com/2011/03/31/typicallimitingvaluesofsubstationequipments/ 5/7
1 10 0.8
2 15 0.9
3 20 1.0
4 25 1.12
5 30 1.25
6 35 1.40
7 40 1.55
8 45 1.75
9 50 1.95
10 55 2.18
11 60 2.42
12 65 2.70
13 70 3.00IfTanDeltaofbushing/winding/CVT/CTismeasuredatoiltemperatureTDeg.C.ThenTanDeltaat20Deg.Cshallbeasgivenbelow:
TanDeltaat20Deg.C=TanDeltaatTempTDeg.C/FactorK.
DewPointLimitsforSF6GasinEHVCircuitBreakers
Sr.No MakeofC.B DewpointatratedPr.Deg.C
CorrespondingdewpointatAtmospheric.Pr. Remarks
1 BHEL15 36
Atthetimeofcommissioning
7 29 DuringO&M
5 27 Critical
2 M&G 39
Atthetimeofcommissioning
32 DuringO&M
3 CGL15 35
Atthetimeofcommissioning
10 31 DuringO&M
4 ABB15 35
Atthetimeofcommissioning
5 26 DuringO&M
5 NGEF15 36
Atthetimeofcommissioning
7 29 DuringO&MNote:DewpointofSF6gasvarieswithpressureatwhichmeasurementiscarriedout.Soitistobeensuredthatifmeasurementisdoneatpressureotherthanatmosphericpressure,itneedstobeconvertedtotheatmosphericpressure.
-
7/13/2015 TypicalLimitingValuesofSubStationEquipments.|ElectricalNotes&Articles
https://electricalnotes.wordpress.com/2011/03/31/typicallimitingvaluesofsubstationequipments/ 6/7
FILEDUNDERUNCATEGORIZED
AboutJignesh.ParmarJigneshParmarhascompletedM.Tech(PowerSystemControl),B.E(Electrical)fromGujaratUniversity.Hehasmorethan13yearsexperienceinPowerTransmissionPowerDistributionElectricalenergytheftdetectionElectricalMaintenanceElectricalProjects(PlanningDesigningcoordinationExecution).HeisPresentlyassociatewithoneoftheleadingbusinessgroupasaDeputyManageratAhmedabad,India.HeisFreelancerProgrammerofAdvanceExcelanddesignusefulExcelSheetsofElectricalEngineeringasperIS,NEC,IEC,IEEEcodes.HeistechnicalAuthorforElectricalMirrorandElectricalIndiaMagazines.HeisTechnicalBloggerandFamiliarwithEnglish,Hindi,Gujarati,Frenchlanguages.HewantstoSharehisexperience&knowledgeandhelptechnicalenthusiaststofindsuitablesolutionsandupdatingthemselvesonvariousEngineeringTopics.
12ResponsestoTypicalLimitingValuesofSubStationEquipments.
S.Krishnamurthysays:July25,2011at6:44amVeryusefulinformationforallsubstationoperating&maintenancepersonnel.Allequipmentsdataisindicatedinoneplace.Bestwishes.
S.K.MURTHY
ReplyVVNRaosays:December17,2011at5:13amHappytoseetheusefulinformation.Ifpossiblepleaseaddrangeandcriticalityoftandeltavaluesandalsotheinternationalstandaredsofclearancesinasubstationaswellasinlines.
Replyvighneshsays:January3,2012at11:20amiamunabletolocateIEC139pertainingtoIRvaluesofwindings.WhatshallbercommendedvaluesofIR?
ReplySsatishShindesays:May25,2012at5:50amThanxforprovidinginstantimportantinformation.
Replymasoomkhansays:July4,2012at10:09amcananyoneprovide380EHVSurgearresterpowerfactor10KVTESTpermissibilelimits
ReplyTikaramwaghadesays:July19,2012at1:04pmThisparametersisexcellencetoimpruvecomfidenceinequptesting
ReplyDineshSinghsays:July31,2012at11:04amThanksforprovidingimportantlimitinginformation.
Replyvinodrathodsays:June10,2013at2:42pmthanksbosscontinuewithstudy
About these ads (https://wordpress.com/about-these-ads/)
-
7/13/2015 TypicalLimitingValuesofSubStationEquipments.|ElectricalNotes&Articles
https://electricalnotes.wordpress.com/2011/03/31/typicallimitingvaluesofsubstationequipments/ 7/7
ReplykirankumarGudlasays:July17,2013at7:25amAtthetimeoffirstcharging
600kV(Gap2.5mm)Minimum
Correctedis
60kV(Gap2.5mm)Minimum
Replysiptrunkingprovidersays:July29,2013at7:12pmHi,ithinkthatisawyouvisitedmysitethusicametoreturnthefavor.
Imattemptingtofindthingstoenhancemywebsite!Isupposeitsoktousesomeofyourideas!!
ReplyAnilPrajapatisays:October8,2013at4:49pmItswonderfulandyouhaveexplainedeverythinginverysimplebutinpowerfulandeffectivewayEr.AnilPrajapati,Jodhpur
ReplyAAAXXXsays:February4,2015at1:50amWhenIwillgofortestingof100MVAtransformerturretcttesting,whattestsIhavetotake?andminimumandmaximumvaluesofthetestswithunit.
Reply
CreateafreewebsiteorblogatWordPress.com.
TheEnterpriseTheme.
Follow
FollowElectricalNotes&Articles
BuildawebsitewithWordPress.com