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1. Earthing and Protection
A.K.Sharma
Professor and Acad. Coordinator-
ECA

2. NationalCrimeRecordsBureauReports
❑2000+deatheveryyearinfireduetoelectricalfault
❑10000+deathdueto electrocution
❑Plus many moreunreported cases
❑Lossofcroresofrupeesduetodamagetoproperty
Canwestopthis?
Basics
Typesof
Earthing
Performance
Protection
Devices
Definitions
Lightning
Protection
EarthTerminal
Design
21-01-2019 Department ofElectricalEngineering,CollegeofEngineeringTrivandrum 22partmentofElectricalEngineering,College ofEngineeringTrivandrum

3. CausedofElectricalAccidents
Reason Result
❑Faultyandfriedwiring
❑Too many equipment in
Extension cords
❑Faultyelectricalappliances
❑Outdatedcircuitbreakers
❑Lightfixturesanddecorations
❑Electricalswitchesandoutlets
❑Unattended chargingpoints
❑Insulationfailure
❑Overcurrent
❑Heatandfire
❑Electrocution
Basics
Typesof
Earthing
Performance
Protection
Devices
Definitions
Lightning
Protection
EarthTerminal
Design
21-01-2019 Department ofElectricalEngineering,CollegeofEngineeringTrivandrum 2321-01-2019 Department ofElectricalEngineering,College ofEngineeringTrivandrum

4. Protection
BasicProtection
❑InsulationofLiveParts
❑BarriersorEnclosure
Fireprevention
❑Smoke/Firedetection
❑FireSuppression
❑Smoke/Firesealing
❑Evacuation
❑Rulesandregulations
Morethan95%oftheaccidents
can be avoided if the supply is
disconnectedwithinthe
stipulatedtime
FaultProtection
❑AutomaticDisconnectionof
supply
❑Doubleinsulation
❑Separation
❑ELVSystem forBuildings
(ExtraLowVoltage)
Basics
Typesof
Earthing
Performance
Protection
Devices
Definitions
Lightning
Protection
EarthTerminal
Design
21-01-2019 Department ofElectricalEngineering,CollegeofEngineeringTrivandrum 2421-01-2019 Department ofElectricalEngineering,College ofEngineeringTrivandrum

5. Standards
❑IS732–CodeforpracticeforElectricalWiringInstallations
❑IS3043–CodeforPracticeofEarthing
❑NBC–NationalBuilding Code2016
❑IEEE142
❑IEC364
Basics
Typesof
Earthing
Performance
Protection
Devices
Definitions
Lightning
Protection
EarthTerminal
Design
21-01-2019 Department ofElectricalEngineering,CollegeofEngineeringTrivandrum 2521-01-2019 Department ofElectricalEngineering,College ofEngineeringTrivandrum

6. EarthingFundamentals
Line1
Line2
Load1 Load2
Fuse
Basics
Typesof
Earthing
Performance
Protection
Devices
Definitions
Lightning
Protection
EarthTerminal
Design
21-01-2019 Department ofElectricalEngineering,CollegeofEngineeringTrivandrum 2621-01-2019 Department ofElectricalEngineering,College ofEngineeringTrivandrum

7. EarthingFundamentals
Basics
Typesof
Earthing
Performance
Protection
Devices
Definitions
Lightning
Protection
EarthTerminal
Design
21-01-2019 Department ofElectricalEngineering,CollegeofEngineeringTrivandrum 2721-01-2019 Department ofElectricalEngineering,College ofEngineeringTrivandrum

8. EarthingFundamentals
Basics
Typesof
Earthing
Performance
Protection
Devices
Definitions
Lightning
Protection
EarthTerminal
Design
21-01-2019 Department ofElectricalEngineering,CollegeofEngineeringTrivandrum 2821-01-2019 Department ofElectricalEngineering,College ofEngineeringTrivandrum

9. EarthingFundamentals
Basics
Typesof
Earthing
Performance
Protection
Devices
Definitions
Lightning
Protection
EarthTerminal
Design
21-01-2019 Department ofElectricalEngineering,CollegeofEngineeringTrivandrum 2921-01-2019 Department ofElectricalEngineering,College ofEngineeringTrivandrum

10. NeedforEarthing
❑Earthingforsafety
(Automaticdisconnectionof powersupply)
❑VoltageReferenceofSystem(Neutral)
❑DissipationofLightningcurrent
❑Basefor Equipotentialisation
❑Shielding against Electromagneticinterference
Basics
Typesof
Earthing
Performance
Protection
Devices
Definitions
Lightning
Protection
EarthTerminal
Design
21-01-2019 Department ofElectricalEngineering,CollegeofEngineeringTrivandrum 101021-01-2019 Department ofElectricalEngineering,College ofEngineeringTrivandrum

11. TypesofEarthing
❑TN
▪TN-S
▪TN-C
▪TN-C-S
❑TT
❑IT
Basics
Typesof
Earthing
Performance
Protection
Devices
Definitions
Lightning
Protection
EarthTerminal
Design
T –Terre (soil)
N-Neutral
S–Separate
C–Combined
I-Isolated
21-01-2019 Department ofElectricalEngineering,CollegeofEngineeringTrivandrum 101121-01-2019 Department ofElectricalEngineering,College ofEngineeringTrivandrum

12. TN-SSystem
Thereis aseparateProtectiveEarthingline
Basics
Typesof
Earthing
Performance
Protection
Devices
Definitions
Lightning
Protection
EarthTerminal
Design
21-01-2019 Department ofElectricalEngineering,CollegeofEngineeringTrivandrum 101221-01-2019 Department ofElectricalEngineering,College ofEngineeringTrivandrum

13. TN-CSystem
EQPT
Earthedat
Source
Earthed at
Distribution
L1
L2
L3
PEN
Basics
Typesof
Earthing
Performance
Protection
Devices
Definitions
Lightning
Protection
EarthTerminal
Design ProtectiveEarth andNeutralareCombined
21-01-2019 Department ofElectricalEngineering,CollegeofEngineeringTrivandrum 101321-01-2019 Department ofElectricalEngineering,College ofEngineeringTrivandrum

14. TN-C-SSystem
Basics
Typesof
Earthing
Performance
Protection
Devices
Definitions
Lightning
Protection
EarthTerminal
Design SeparatePE andNforonesectionandcombinedPEandNfortheother
section
21-01-2019 Department ofElectricalEngineering,CollegeofEngineeringTrivandrum 101421-01-2019 Department ofElectricalEngineering,College ofEngineeringTrivandrum

15. TTSystem
Basics
Typesof
Earthing
Performance
Protection
Devices
Definitions
Lightning
Protection
EarthTerminal
Design Earthcurrent flowsthroughgroundonly
21-01-2019 Department ofElectricalEngineering,CollegeofEngineeringTrivandrum 101521-01-2019 Department ofElectricalEngineering,College ofEngineeringTrivandrum

16. ITSystem
Basics
Typesof
Earthing
Performance
Protection
Devices
Definitions
Lightning
Protection
EarthTerminal
Design Nodirectgroundingatsourceside;insulation monitoringisessential
21-01-2019 Department ofElectricalEngineering,CollegeofEngineeringTrivandrum 101621-01-2019 Department ofElectricalEngineering,College ofEngineeringTrivandrum

17. Compare EarthingSystems
EQPT
Earthedat
Source
Protective Earthing
atDistribution
L1
L2
L3
N
PE
EQPT
Earthedat
Source
Earthed at
Distribution
L1
L2
L3
N
PE
EQPT
Earthedat
Source
Earthed at
Distribution
L1
L2
L3
PEN
TT TN-S TN-C
TN-C-S IT
Basics
Typesof
Earthing
Performance
Protection
Devices
Definitions
Lightning
Protection
EarthTerminal
Design
21-01-2019 Department ofElectricalEngineering,CollegeofEngineeringTrivandrum 101721-01-2019 Department ofElectricalEngineering,College ofEngineeringTrivandrum

18. TN-SSystemLoop Impedance
s
I
a
Loopimpedance,Z=
U
0
Where
a
U
0=conventionalvoltagelimits
I=currentensuringtheautomaticoperation
ofdisconnectingdevice
Basics
Typesof
Earthing
Performance
Protection
Devices
Definitions
Lightning
Protection
EarthTerminal
Design
21-01-2019 Department ofElectricalEngineering,CollegeofEngineeringTrivandrum 101821-01-2019 Department ofElectricalEngineering,College ofEngineeringTrivandrum

19. ImportanceofLoopImpedance
Z
S I
SC Action Remark
1.0Ω240A DevicewillnottripUnsafe
0.5Ω480ADevicewilltripdelayedUnsafe
0.1Ω2400ADevicewilltripquicklySafe
Voltage=240V OCPD–250AMCCB
Basics
Types of
Earthing
Performance
Protection
Devices
Definitions
Lightning
Protection
EarthTerminal
Design
21-01-2019 Department ofElectricalEngineering,CollegeofEngineeringTrivandrum 101921-01-2019 Department ofElectricalEngineering,College ofEngineeringTrivandrum

20. DisconnectiontimeasperIS3043
220voltsfault
0.17secfordrycondition
0.035secfor wet condition
Basics
Typesof
Earthing
Performance
Protection
Devices
Definitions
Lightning
Protection
EarthTerminal
Design
21-01-2019 Department ofElectricalEngineering,CollegeofEngineeringTrivandrum 102021-01-2019 Department ofElectricalEngineering,College ofEngineeringTrivandrum

21. LoopImpedanceinTTSystem
Loopimpedanceishigh;SoRCDprotectionisessential
Basics
Typesof
Earthing
Performance
Protection
Devices
Definitions
Lightning
Protection
EarthTerminal
Design
21-01-2019 Department ofElectricalEngineering,CollegeofEngineeringTrivandrum 102121-01-2019 Department ofElectricalEngineering,College ofEngineeringTrivandrum

22. ITSystem
❑AsinputtounearthedIT systems,eithera transformeroran independentpower
source,suchasabatteryor ageneratorareused.
❑Nohigh faultcurrentflowsintheeventofa shortcircuittoexposedconductivepartor
anearthfault.
Asrequiredby thestandards,aninsulationmonitoringdeviceis mandatoryinanIT
system.
❑Inanunearthedsystem,afirstfaultdoesnotinterruptthesystempowersupply and
thereforeincreasesthe availabilityofthe system.
Basics
Types of
Earthing
Performance
Protection
Devices
Definitions
Lightning
Protection
EarthTerminal
Design
21-01-2019 Department ofElectricalEngineering,CollegeofEngineeringTrivandrum 102221-01-2019 Department ofElectricalEngineering,College ofEngineeringTrivandrum

23. ComparisonofEarthingSystems
TT IT TN-S TN-C TN-C-S
Earthfaultloop
impedance
High Highest Low Low Low
RCDpreferred? Yes N/A Optional No Optional
PEconductorcost Low Low Highest Least High
Riskofbrokenneutral No No High Highest High
Safety Safe LessSafe SafestLeastSafeSafe
Safetyrisks
High loop
impedance
Doublefault,
overvoltage
Broken
neutral
Broken
neutral
Broken
neutral
Advantages
Safeand
reliable
Continuity of
operation,cost
Safest Cost
Safetyand
cost
Basics
Typesof
Earthing
Performance
Protection
Devices
Definitions
Lightning
Protection
EarthTerminal
Design
21-01-2019 Department ofElectricalEngineering,CollegeofEngineeringTrivandrum 102321-01-2019 Department ofElectricalEngineering,College ofEngineeringTrivandrum

24. Applications
Type Applications
TT
Overheadpowerdistributionforresidential/commercialfromacommon
Transformer.EveryinstallationshallhaveanRCDandanearthelectrodeatOriginof
installation
TN-S
Industrial/commercial/ITBuildingswithelectronicsystemsandTransformerwithin
facility(transformeroperatedby theowner)
TN-C OverHeadPowerDistributionuptoOriginof anInstallation.
TN-C-S
Overheadpowerdistributionforresidential/commercialfromacommonTransformer.
RCDandearthelectrodeatoriginofinstallationareoptional.
IT
Hospitals/ITinstallationforabuildingorpartofabuilding.Notsuitablefordifferent
buildingswithsamesupply
Basics
Typesof
Earthing
Performance
Protection
Devices
Definitions
Lightning
Protection
EarthTerminal
Design
21-01-2019 Department ofElectricalEngineering,CollegeofEngineeringTrivandrum 102421-01-2019 Department ofElectricalEngineering,College ofEngineeringTrivandrum

25. OvercurrentProtectiveDevices(OCPD)
FUSE MCB MCCB
ACB
Trippingoccursduetooverload, shortcircuitorearth fault.
Forquick disconnectionapprox. 10times ratedcurrentshallflow
220 volt fault Disconnection time in final circuit:
Drycondition –0.170sec
Wetcondition–0.035sec
Basics
Typesof
Earthing
Performance
Protection
Devices
Definitions
Lightning
Protection
EarthTerminal
Design
21-01-2019 Department ofElectricalEngineering,CollegeofEngineeringTrivandrum 102521-01-2019 Department ofElectricalEngineering,College ofEngineeringTrivandrum

26. ResidualCurrentProtectiveDevices
ELCB RCCB RCBO
ResidualCurrentCircuitBreaker ResidualCurrentBreakover
RCCB+MCB
Basics
Typesof
Earthing
Performance
Protection
Devices
Definitions
Lightning
Protection
EarthTerminal
Design
VoltagesensingEarth
Leakage Circuit Breaker
Nowobsolete
21-01-2019 Department ofElectricalEngineering,CollegeofEngineeringTrivandrum 102621-01-2019 Department ofElectricalEngineering,College ofEngineeringTrivandrum

27. RCCBPrinciple
2Pole-RCCB 4Pole-RCCB
Basics
Typesof
Earthing
Performance
Protection
Devices
Definitions
Lightning
Protection
EarthTerminal
Design
21-01-2019 Department ofElectricalEngineering,CollegeofEngineeringTrivandrum 102721-01-2019 Department ofElectricalEngineering,College ofEngineeringTrivandrum

28. ElectricShockLevels
❑ElectricalSensation
▪0.3mAto 0.4mA
❑PerceptionLet-Go
▪0.7mAto 1.1mA
❑MaximumLet-GoLevel
▪10mA(Female)
▪16mA(Male)
❑FibrillationLevel
▪50 mA for0.2Secs(female)
▪75mA for0.5Secs(Male)
Basics
Typesof
Earthing
Performance
Protection
Devices
Definitions
Lightning
Protection
EarthTerminal
Design
Automaticdisconnectionofsupplyshould happenbeforetheprescribedtime
21-01-2019 Department ofElectricalEngineering,CollegeofEngineeringTrivandrum 102821-01-2019 Department ofElectricalEngineering,College ofEngineeringTrivandrum

29. Definitions
❑ReferenceEarth—theconductivemassoftheearth,whoseelectricpotential
atanypointofthismassofearthistakenaszerowithreferencetoanearthing
systemofelectricalpowersystemorelectricalinstallationsinabuilding.
❑Earthingsystem-arrangementofconnectionsanddevicesnecessarytoearth
equipmentorasystemseparatelyorjointly.
❑EarthElectrode—Aconductororgroupofconductorsinintimatecontactwith
andprovidinganelectricalconnectiontoearth.
❑Earthgrid–earthelectrodeintheformoftwooverlappinggroupsofburied,
parallel,horizontalelectrodesusuallylaidapproximatelyatrightangletoeach
otherwiththeelectrodesbondedateachintersection.Earthgridprovides
commongroundforelectricaldevicesandmetallicstructures.
❑EarthElectrodeResistance—Theresistancetoearthofanearthelectrodeor
earthgrid.
Basics
Typesof
Earthing
Performance
Protection
Devices
Definitions
Lightning
Protection
EarthTerminal
Design
21-01-2019 Department ofElectricalEngineering,CollegeofEngineeringTrivandrum 102921-01-2019 Department ofElectricalEngineering,College ofEngineeringTrivandrum

30. Definitions
❑EarthFaultLoopImpedance—Theimpedanceoftheearthfaultcurrentloop
(phase-to-earthloop)startingandendingatthepointofearthfault.
❑EarthLeakageCurrent—Acurrentwhichflowstoearthortoextraneous
conductivepartsinacircuitwhichiselectricallysound.
❑EarthingConductor—Aprotectiveconductorconnectingthemainearthing
terminaltoanearthelectrodeortoothermeansofearthing.
❑ElectricallyIndependentEarthElectrodes—Earthelectrodeslocatedatsucha
distancefromoneanotherthatthemaximumcurrentlikelytoflowthrough
oneofthemdoesnotsignificantlyaffectthepotentialoftheother(s).
❑EquipotentialBonding—Electricalconnectionputtingvariousexposed
conductivepartsandextraneousconductivepartsatasubstantiallyequal
potential.
Basics
Typesof
Earthing
Performance
Protection
Devices
Definitions
Lightning
Protection
EarthTerminal
Design
21-01-2019 Department ofElectricalEngineering,CollegeofEngineeringTrivandrum 103021-01-2019 Department ofElectricalEngineering,College ofEngineeringTrivandrum

31. Definitions
❑FunctionalEarthing—Connectiontoearthnecessaryforproperfunctioningof
electricalequipment
❑NeutralConductor—Aconductorconnectedtotheneutralpointofasystem
andcapableofcontributingtothetransmission ofelectrical energy.
❑PENConductor—Aconductorcombiningthefunctionsofbothprotective
conductorandneutralconductor.
❑EarthPotential–Electricpotentialwithrespecttogeneralmassofearthwhich
occursin,oronthesurfaceofthegroundaroundanearthelectrodewhenan
electriccurrentflowsfromtheelectrodetoearth.
❑EarthPotentialrise–Voltagebetweenanearthingsystemandreferenceearth
Basics
Typesof
Earthing
Performance
Protection
Devices
Definitions
Lightning
Protection
EarthTerminal
Design
21-01-2019 Department ofElectricalEngineering,CollegeofEngineeringTrivandrum 103121-01-2019 Department ofElectricalEngineering,College ofEngineeringTrivandrum

32. Definitions
❑Equipotential LineorContour—Thelocus ofpointshaving thesamepotential
ata giventime.
❑Mutual ResistanceofGroundingElectrodes—Equaltothevoltagechangein
one ofthemproducedbyachangeofoneampereofdirectcurrentin the
other and isexpressedinohms.
❑EarthGrid—Asystemofgroundingelectrodesconsistingofinter-connected
connectorsburiedinthe earthtoprovide acommongroundforelectrical
devices andmetallicstructures.
NOTE—The term'earthgrid'does notinclude'earthmat'.
❑EarthMat—Agroundingsystemformedbyagridofhorizontallyburied
conductorsandwhichservestodissipate the earthfaultcurrenttoearthand
alsoas anequipotentialbondingconductorsystem.
Basics
Typesof
Earthing
Performance
Protection
Devices
Definitions
Lightning
Protection
EarthTerminal
Design
21-01-2019 Department ofElectricalEngineering,CollegeofEngineeringTrivandrum 103221-01-2019 Department ofElectricalEngineering,College ofEngineeringTrivandrum

33. Definitions
❑PME-Protectivemultiple earthing
❑CNE-Combinedneutraland earth
❑PEN-Aconductorcombining thefunctionsof both
protectiveconductorand neutralconductor
❑MET–MainEarthingTerminal
Basics
Typesof
Earthing
Performance
Protection
Devices
Definitions
Lightning
Protection
EarthTerminal
Design
21-01-2019 Department ofElectricalEngineering,CollegeofEngineeringTrivandrum 103321-01-2019 Department ofElectricalEngineering,College ofEngineeringTrivandrum

34. StatutoryProvisions
❑Allequipmentofvoltagesof250voltsto650voltsshallbe
earthedbytwoseparateanddistinctconnectionswithearth.
❑Eachearthsystemshallbesodevisedthatthetestingof
individualearthelectrodeispossible.
❑Asfaraspossible,allearthconnectionsshallbevisiblefor
inspection.
❑Nocut-out,linkorswitchotherthanalinkedswitcharranged
tooperatesimultaneouslyontheearthedorearthedneutral
conductorandtheliveconductors,shallbeinsertedonany
supplysystem.
▪This,however,doesnotincludethecaseofaswitchforusein
controllingageneratororatransformer oralinkfortestpurposes.
Basics
Typesof
Earthing
Performance
Protection
Devices
Definitions
Lightning
Protection
EarthTerminal
Design
21-01-2019 Department ofElectricalEngineering,CollegeofEngineeringTrivandrum 103421-01-2019 Department ofElectricalEngineering,College ofEngineeringTrivandrum

35. ReasonforAccidents
❑Houses/shops/buildingsetc-L.Vpublicelectricity distribution
▪SafetyregulationsandstandardsarenotunderstoodbyUtilities.Asa
result TTnetworkisusedwithoutRCD
▪Conditions of ADS (automatic disconnection of supply) are not
followedbyutilities.Asa resultprotectivedevicewonttrip during
fault.
▪ADSwillnotworkwhenpoweredfromGenerators/UPS/Inverters
dueto insufficientfaultcurrent.
Basics
Typesof
Earthing
Performance
Protection
Devices
Definitions
Lightning
Protection
EarthTerminal
Design
21-01-2019 Department ofElectricalEngineering,CollegeofEngineeringTrivandrum 103521-01-2019 Department ofElectricalEngineering,College ofEngineeringTrivandrum

36. ReasonforAccidents
❑Industrial / commercial/multistoriedbuildings(HTsupply)
▪Safetyregulationsandstandardsarenotunderstood. Asa resultTT
networkisusedinsteadofTN-S withPME
▪SourcessuchasTransformerandDG–Neutralareearthedinsoil
separatelycreating highimpedancepath forfaultcurrent as aresult
primaryprotectivedevicewillneveroperateduring fault.
▪METandequipotentialisation isunknownandnotfollowed.
▪Loop impedance test and ADS (Auto disconnection of supply) is not
carriedout.
▪ADSwillnotworkwhenpoweredfromGenerators/UPS/Inverters
dueto insufficientfaultcurrent.
Basics
Typesof
Earthing
Performance
Protection
Devices
Definitions
Lightning
Protection
EarthTerminal
Design
21-01-2019 Department ofElectricalEngineering,CollegeofEngineeringTrivandrum 103621-01-2019 Department ofElectricalEngineering,College ofEngineeringTrivandrum

37. EarthingforLightningProtection
TypeBArrangement
(RingConductor)
TypeA TypeB
Basics
Typesof
Earthing
Performance
Protection
Devices
Definitions
Lightning
Protection
EarthTerminal
Design
21-01-2019 Department ofElectricalEngineering,CollegeofEngineeringTrivandrum 103721-01-2019 Department ofElectricalEngineering,College ofEngineeringTrivandrum

38. EarthingforLightningProtection
Basics
Typesof
Earthing
Performance
Protection
Devices
Definitions
Lightning
Protection
EarthTerminal
Design
21-01-2019 Department ofElectricalEngineering,CollegeofEngineeringTrivandrum 103821-01-2019 Department ofElectricalEngineering,College ofEngineeringTrivandrum

39. EarthingforLightningProtection
Basics
Typesof
Earthing
Performance
Protection
Devices
Definitions
Lightning
Protection
EarthTerminal
Design
21-01-2019 Department ofElectricalEngineering,CollegeofEngineeringTrivandrum 103921-01-2019 Department ofElectricalEngineering,College ofEngineeringTrivandrum

40. EarthingforLightningProtection
Basics
Typesof
Earthing
Performance
Protection
Devices
Definitions
Lightning
Protection
EarthTerminal
Design
21-01-2019 Department ofElectricalEngineering,CollegeofEngineeringTrivandrum 104021-01-2019 Department ofElectricalEngineering,College ofEngineeringTrivandrum

41. SignificanceofEarth Resistance
Basics
Typesof
Earthing
Performance
Protection
Devices
Definitions
Lightning
Protection
EarthTerminal
Design
21-01-2019 Department ofElectricalEngineering,CollegeofEngineeringTrivandrum 104121-01-2019 Department ofElectricalEngineering,College ofEngineeringTrivandrum

42. EarthElectrodes
60cm
1.25 m
(MIN)
2.5 m
(MIN)
CastIroncoverGroundlevel
19mmdiaGI
pipe
Cementconcrete
Alternatelayers
ofcharcoaland
salt
EarthWire
12.7mmdiaGI
pipe
38mmdiaGIpipe
12mmdia hole
Funnelwithwire
mesh
PipeEarthing PlateEarthing
Newdevelopmentsarecomingup
Basics
Typesof
Earthing
Performance
Protection
Devices
Definitions
Lightning
Protection
EarthTerminal
Design
21-01-2019 Department ofElectricalEngineering,CollegeofEngineeringTrivandrum 104221-01-2019 Department ofElectricalEngineering,College ofEngineeringTrivandrum

43. PlanningforEarthTerminal
Aesthetics,Effectivenessand maintenancerequirements
areto beconsidered
Basics
Typesof
Earthing
Performance
Protection
Devices
Definitions
Lightning
Protection
EarthTerminal
Design
21-01-2019 Department ofElectricalEngineering,CollegeofEngineeringTrivandrum 104321-01-2019 Department ofElectricalEngineering,College ofEngineeringTrivandrum

44. StructuralEarthing
Basics
Typesof
Earthing
Performance
Protection
Devices
Definitions
Lightning
Protection
EarthTerminal
Design
21-01-2019 Department ofElectricalEngineering,CollegeofEngineeringTrivandrum 104421-01-2019 Department ofElectricalEngineering,College ofEngineeringTrivandrum

45. StructuralEarthing
1.air-terminationconductor
2.metalcoveringofthe roof parapet
3.steelreinforcingrods
4.mesh conductorssuperimposedonthe
reinforcement
5.jointofthemeshconductor
6.joint foraninternalbondingbar
7.connectionmadebyweldingorclamping
8.arbitraryconnection
9.steelreinforcementinconcrete(with
superimposedmeshconductors)
10.ringearthingelectrode(if any)
11.foundationearthingelectrode
Basics
Typesof
Earthing
Performance
Protection
Devices
Definitions
Lightning
Protection
EarthTerminal
Design
21-01-2019 Department ofElectricalEngineering,CollegeofEngineeringTrivandrum 104521-01-2019 Department ofElectricalEngineering,College ofEngineeringTrivandrum

46. Equipotentialbonding
Basics
Typesof
Earthing
Performance
Protection
Devices
Definitions
Lightning
Protection
EarthTerminal
Design
21-01-2019 Department ofElectricalEngineering,CollegeofEngineeringTrivandrum 104621-01-2019 Department ofElectricalEngineering,College ofEngineeringTrivandrum

47. ThankYou
21-01-2019 Department ofElectricalEngineering,CollegeofEngineeringTrivandrum 104721-01-2019 Department ofElectricalEngineering,College ofEngineeringTrivandrum