electrical earthing and bonding system

2/2/2011

1

A Warm Welcome to All Delegates

A Technical Presentation on

McML

1

Earthing & Bonding System

By

Mr T N Rao

McML Protection Technologies Pvt LtdHyderabad

McMLEarthing&BondingSystem McMLEarthing&BondingSystem

Earthing&BondingSystemATechnicalPresentationon

McML Protection Technologies Pvt LtdMcML Protection Technologies Pvt Ltd

McML Protection Technologies Pvt LtdPlot No 42 , Vijaypuri Colony

Sainikpuri, Hyderabad- 62

Mobile : +91-9704456808Fax : +91-40-4012 0478

Email : [email protected] : www.mcmlptl.com

McMLEarthing&BondingSystemAgenda

Introduction Codes & Standards Design Principles Soil Resistivity , Measurement of soil resistivity Treatment of soil , Earth Enhancing Compound

Earth Resistance Measurement of Earth Resistance

McML Protection Technologies Pvt Ltd 2Feb113

Earth Resistance , Measurement of Earth Resistance Deep Earth or Multiple earth pits Permanent Connections Exothermic welding Common Bonding Network (CBN) Case studies RDSO Specification Practical

Measurement of soil resistivity Measurement of earth resistance

McMLEarthing&BondingSystem

Modern electronic equipment is sensitive.

More susceptible to surges and electromagnetic interferences.

Components size is reduced.

More components per chip.

Why failures are more now ?

McML Protection Technologies Pvt Ltd4

p p p

Poor Insulation resistance.

More number of appliances

An effective low impedance earthing ismandatory for any protective device tooperate and protect the equipment

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McMLEarthing&BondingSystemIntroduction

EarthingisanintegralpartofanymodernElectrical&Electronicequipmentprotectionsystemdesign.

An effective, lowimpedance ground system is a key element ofpower quality assurance.

Itiscrucialnotonlytoensurepersonnelsafetybut,toprovideli bl t ti f it l i t

McML Protection Technologies Pvt Ltd

reliableprotectionforvitalequipment: Reducingambientnoiselevels Improvedsystemperformance Toincreaseequipmentlife Tominimizeinterruptionsofserviceandcostlydowntime.

5 2Feb11 2Feb11

McMLEarthing&BondingSystemCodes & Standards:

IS 3043:1987 - Code of Practice for Earthing

IEEE Standard 80 - IEEE Guide for Safety in AC Substation Grounding

IEEE Standard 1100 - IEEE Recommended Practice for Powering and GroundingElectronic Equipment ( IEEE Emerald book)

IEEE Standard 142 - IEEE Recommended Practice for Grounding ofIndustrial and Commercial Applications( IEEE Green book)

IEEE Standard 81 - Recommended Guide for Measuring Ground


IEEE Standard 81 Recommended Guide for Measuring GroundResistance and Potential Gradients in the Earth

IEEE Standard 837 - IEEE Standard for Qualifying Permanent Connections Used in Substation Grounding

IEC 60364-5-2002 - Electrical installations of buildings

ANSI UL 467 - Grounding and Bonding Equipment

BS 7430: 1998 - Code of Practice for Earthing

BS EN 50164-7:2008 - Requirements for Earthing Enhancing Compounds

6 2Feb11

McMLEarthing&BondingSystemDesign of Earthing System :

1. TypeofEarthing2. ElectrodeMaterial3. ElectrodesShape4. ElectrodeTypes


5. SoilResistivity6. SoilTreatment7. MultiplePitsorDeepElectrode8. Bonding PermanentConnections

2February20112Feb11

McMLEarthing&BondingSystemClassification of Earthing / Grounding

Safety or Protective Earth - For safety of personnelMain Earth, General Electrical Earth, Equipment Grounding, Body EarthingAssociated with Non current carrying body/ conductor


System or Technical Earth - For stable earth reference or noise suppression

DC Earth, System Neutral, Telecom Earth, Instrumentation EarthFunctional, Clean EarthAssociated with current carrying current conductor

2Feb11

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McMLEarthing&BondingSystemElectrode Material

1. Protection against CorrosionCorrosionResistance ofdifferentmetals

Copper(0.2%) CastIron/MS(2.2%)


2. Protective Coating Copperbondedelectrodes 0.2%peryear(Recommendedmin250microns)

HotdipGalvanization(GI) 0.5%peryear3. High tensile low carbon steel

MaterialgradeBS4360grade43A Tensilestrengthofmin600N/mm2

2February20112Feb11

McMLEarthing&BondingSystem1. Underground Corrosion National Bureau of Standards Circular 579From 1910 to 1955, the National Bureau of Standards conducted an extensive undergroundcorrosion study in which 36,500 specimens, representing 333 varieties of ferrous, nonferrous,and protective coating materials were exposed in 128 test locations throughout the UnitedStates.

In cooperation with the National Association of Corrosion Engineers, the NCEL conducted a7-year program of testing metal rods for electrical grounding. Copper bonded, stainless clad,and galvanized steel rods were included among other materials

2. Field Testing of Electrical Grounding Rods Naval Civil Engineering Laboratory (NCEL)

Technical Reports : Review


and galvanized steel rods were included among other materials.

3.National Electrical Grounding Research Project (NEGRP) Pawnee Site Excavation

The NEGRP was started in 1992 to compare the long-term performance of different types of grounding electrodes.

In 2003, one of the original sites (Pawnee) was excavated and the electrodes removed 5/8 copper bonded and galvanized rod samples were exhumed. The results were definitive : The 5/8 copper bonded rod was virtually free of corrosion while the galvanized rod showed significant deterioration (see the pictures on next slide).

2Feb11

McMLEarthing&BondingSystemNational Electrical Grounding Research Project Pawnee Site Excavation



x10galvanizedrodremovedafter10years(PawneeSite).

2February2011

11

5/8 x 8 Copper Bonded ground rod removed after 10 years (Pawnee Site).


National Electrical Grounding Research Project Pawnee Site Excavation



3/4x10galvanizedrodremovedafter10years

12

5/8 x 8 Copper Bonded ground rod removed after 10 years

Recommendations :10 mil copper coating: Service life - up to 40 years.

UL 467 recommends 10 mils (0.25mm) of copper coating

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McMLEarthing&BondingSystemUL 467 Grounding & Bonding Equipment

R

E322481



Vertical Electrodes

Plate Electrodes

Horizontal Strip Electrodes

Electrode Shape


The low current density can be achieved by designing the electrodein such a way that the dimensions in one direction is large comparedto the other two, thus a pipe/rod has a much lower resistance than aplate of equal surface area.

PlateElectrodesarenotverycommonastheyarenotaseffectiveasverticalelectrodeandalsoexpensive.

2February2011

McMLEarthing&BondingSystemTypes of Earth Electrodes

Vertically Electrodes Pipe or copper clad steel

Plate Electrodes 2ft x 2ft x 6 mm copper plate is used.

Horizontal Strip Electrodes

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A strip is buried in a trench in rocky area

Ring Earth Earthing conductor buried around building perimeter

Chemical Earth Rods Integral chemical treatment

Ufer Earth Metallic conductor embedded in structural concrete

2Feb11


IEC603645:ElectricalinstallationsofbuildingsElectrodes : Copperbondedroddia =14mmcoating90micronsminimum. Copperstrip50sqmm(25x2mm). GIstrip=90sqmm(30x3mm)(6070microns)

Earthing Conductor Sizing

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February

p q ( ) ( ) GIPipe=25sqmm(2mmthickness)EarthingConductor:Mincrosssectionalarea(Cl 542.3) Protectedagainstcorrosion 16sqmmcopper Notprotectedagainstcorrosion 25sqmm.copper,50sqmm.FeEquipotential bondingaccordingto413.1.2.1ofIEC60364441 6mmcopper;or 16mmaluminium;or 50mmsteel

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McMLEarthing&BondingSystemEarthing Conductor Sizing

IEEE837

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McMLEarthing&BondingSystemSoil Resistivity


McMLEarthing&BondingSystemEarth Resistance Testers Ground Resistance Tester

3 or 4-wire Tester

Types : Analogue Digital Clamp on

FlukeMegger


Clamp on

GEOHMClamp OnDigital Analogue

McMLEarthing&BondingSystemSoil Resistivity Measurement Wenner Method


SoilResistivity()=2aR2Feb1120

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SoilResistivity()=2aR

2Feb1121


Microsoft Office


Microsoft Office el 97-2003 Worksh

McMLEarthing&BondingSystemTypical Soil Resistivity


McMLEarthing&BondingSystemSoil Resistivity - Effect of Salt, Moisture and Temperature


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McMLEarthing&BondingSystemSoil Treatment to lower the resistivity

Conventional Methods

Use of sodium chloride, magnesium, and copper sulfates, or calciumchloride, to increase the conductivity of the soil immediatelysurrounding an electrode.


State or federal authorities may not permit using this methodbecause of possible leaching to surrounding areas.

The salt treatment must be renewed periodically.

Corrode and damage the earth electrode

2Feb1125

McMLEarthing&BondingSystemSoil Treatment to lower the resistivity

BS EN /IEC 50164-7 : the European (CENELEC ) standard specifies therequirements for earthing enhancing compounds.

EEC effectively increase the diameter of the electrode by modifying the soilsurrounding the electrode

Earth Enhancing Compounds


surrounding the electrode.

EEC increases the contact surface area of the earth electrodes.

Cathodic Protection does not damage the earth electrode.

The EEC does not polluting the environment.

Note : Refill products are not in the scope of the standard

2Feb1126


Highly conductive cementious compound Increases the contact surface area Homogeneous and stable Doesn't leach into the ground Doesnt corrode the electrode Enhances the life of earth electrode.

Earthing Enhancing Compound


Enhances the life of earth electrode. Environmentally Friendly

Low Resistivity Suitable for all terrain Can be used in dry or slurry form Permanent and Maintenance Free Comply BS EN/IEC 50164-7 (

McMLEarthing&BondingSystemGraphite based Earth Enhancing Materials


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McMLEarthing&BondingSystemEarth Enhancing Compound- Application

Earth enhancement materials are typically placedaround the rod in an augured hole or around groundingconductors in a trench, in either a dry form orpremixed in a slurry.


McMLEarthing&BondingSystemElectrode Resistance Development


McMLEarthing&BondingSystemEarth Resistance

1. Resistance of the electrode .2. Contact Resistance between the electrode and the soil3 Resistance of the soil from the electrode surface outward

Factors affecting Earth Resistance


3. Resistance of the soil from the electrode surface outward

The first two are negligible part of total resistance The resistance of an earth is primarily determined by the

soil resistivity

2Feb1131

McMLEarthing&BondingSystemEarth Resistance


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McMLEarthing&BondingSystemEarth Resistance Calculation

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McMLEarthing&BondingSystemEarth Resistance Calculation


McMLEarthing&BondingSystemEarth Resistance of Vertical Electrode


The most commonly used formula for single ground electrode systemsDeveloped by Prof. H B Dwight of the MIT.

2Feb1135


Microsoft Office

Earth Resistance of Vertical Electrode


Microsoft Office el 97-2003 Worksh

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McMLEarthing&BondingSystemHow to reduce earth resistance ?

Increase the length of the electrode?

Increase the dia of the electrode ?

Use multiple earth pit ?


p p

Improve the soil resistivity ?

2February2011

McMLEarthing&BondingSystemDeep Earth Electrode System

ElectrodeDia

McML Protection Technologies Pvt Ltd38 2February2011

Electrodelengthinm

McMLEarthing&BondingSystemDeep Earth Electrode System

Time :

50 (-m)Rod Dia 12 mm 17 mm 19mm 25 mm

Length (m) 0.012 0.017 0.019 0.025

1 38.27 35.50 34.61 32.432 21.89 20.51 20.06 18.973 15.67 14.75 14.45 13.724 12.33 11.63 11.41 10.875 10.22 9.66 9.48 9.056 8.75 8.29 8.15 7.78

Design Engineer

Project : Deep Earth Electrode System

T N Rao

Location :

Customer :

Soil Resistivity

McM L Protection Technologies

Length and Dia of Electrode

Rr={/2**lr}*{ln(4*lr/D)-1}, when


Rev. No.: 0

Checked By Approved By

Mr.T.N.RaoMr.SumadeepForm. No.: TEC-SFS-04

Mr.Sasirekha

Prepared By

35.50

20.51

14.75

11.639.48 8.15

32.43

18.97

13.7210.87

9.05 7.78

0

5

10

15

20

25

30

35

40

45

50

1 2 3 4 5 6

EarthR

esistancein

Ohms

EarthResistance Homogeneoussoil

12mm17mm19mm25mm


ShallowEarthing DeepEarthing

Limited Electrode Length- 6 to 8 feet

Doesnt touch natural soil

Offers Inconsistent resistance

Deep Driven Electrode > 12 feet

Greater contact with low resistantnatural soil

Maintains consistent resistance

Shallow / Deep Earth Grounding

LORESS


Offers Inconsistent resistance

Earth enriching agents - salt, charcoal,are used

Has environmental concerns

Maintenance required

Short term solution

over time

No such chemical agents are used.

No environmental concerns.

Maintenance free

Permanent & Economical solution

2February2011

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McMLEarthing&BondingSystemElectrodes in Parallel

A useful rule is that grounding systems of 224 rods placed one rod length apart in aline, hollow triangle, circle, or square will provide a grounding resistance divided bythe number of rods and multiplied by the factor F taken from Table

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2011

McMLEarthing&BondingSystemSphere of Influence


McMLEarthing&BondingSystemSphere of Influence Spacing between electrodes




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McMLEarthing&BondingSystemMeasurement of Earth Resistance

Fall of Potential Method


McMLEarthing&BondingSystemMeasurement of Earth Resistance

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McMLEarthing&BondingSystemMeasurement of Earth Resistance - Fall of Potential Method


McMLEarthing&BondingSystemMeasurement of Earth Resistance - Fall of Potential Method


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Permanent Joint Durable and Reliable Corrosion Free

Exothermic Weld Connections

Permanent Connections


Offer no contact resistance High Current Capacity CPRI Testing

. The best choice where safety, reliability, current carrying capacity and longevity are critical.

2February20112Feb1149

McMLEarthing&BondingSystemExothermic Welding Process LORESS

McML Protection Technologies Pvt Ltd2February20112Feb1150


Mandatory acc. to the following Standards:

ANSI IEEE Standard 80 IEEE Guide forSafety in AC Substation Grounding

IEEE Standard 837 IEEE Standard for

LORESSExothermic Welding Process


Qualifying Permanent Connections Used inSubstation Grounding

ANSI UL 467 Grounding and BondingEquipment

ANSI-J-STD-607-A Commercial BuildingGrounding (Earthing) and BondingRequirements for Telecommunications



The earth system has to be considered as an integrated system,telecommunications earth cannot be considered independently of powerearth or lightning earth.

Earthing as a system

Common Bonding Network (CBN)


earth or lightning earth.

More than one earth systems will be connected to some equipment therebycreating current paths that might not have been planned, might not beadequate, or might not remain continuous.

Circulating currents and potential differences between the earth systemscan damage the equipment.

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McMLEarthing&BondingSystemEquipotential Bonding - Use of Isolation Spark Gaps


Conducting Parts of InstallationNon Conducting Parts of Installation

2February2011

McMLEarthing&BondingSystemCommon Bonding Network (CBN)

Bond all ground points to eliminate ground loops and create anequipotential plane

Regulation requires that everything that is conductive is to be connectedto the network of protective conductors to create building CBN

All earth pits water pipe line gas pipeline and metal works ( metal stair


All earth pits, water pipe line, gas pipeline and metal works ( metal staircase etc )to be bonded together in an installation.

Use Isolation Spark Gap devices for equipotential bonding of Conductingand non conducting parts of the electrical installations.

54 2February2011


Lowinresistanceandimpedance. Adequatecurrentcarryingcapacity Durableandreliable Goodcorrosionresistance

Characteristics of an effective / good Earthing :


Consistencyinlowresistance Areliablelifeof2530years MaintenanceFree Complywithnationalandinternationalcodes



HoweffectiveisyourEarthingSystem?


9095%ofallfacilitiesinspectedlackaneffectiveEarthingsystem.

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McMLEarthing&BondingSystemConventional/TraditionalEarthing

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McMLEarthing&BondingSystemConventionalEarthing

Is bolt nut mechanism a permanent solution ?

Is it non corrosive ?

Is it touching the natural soil ?


Can it offer consistentresistance ?

Can it carry the required current safely to ground ?

Is it Maintenance Free ?



LORESSTM

Here is the solution from McML

LORESS


LORESS

59

ACompleteMaintenanceFreeEarthingSolution

R

E322481

Approved and Tested by International / National certifying bodies

CPRI



Copper bonded Rods

Compression Couplers

LORESSUnique features of the solution

R

E322481


February60

Earth Enhancing Compound

Connections using Exothermic Welding

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High tensile low carbon steel Complies BS 4360 grade 43A 6 10 long X - dia Molecularly bonded with 99.9% copper Coating thickness - 10 mil ( 254 microns)

Copper Bonded RodsR

E322481


Coating thickness 10 mil ( 254 microns) UL listed Rods Tensile strength of min 600 N/mm2

Bending strength of min 12.12 KN CPRI + tested 23 kA for 1 second Meets IS:3043 , UL 467, EN 50164-2 standards Service Life - up tyo 40 years

2February2011

McMLEarthing&BondingSystemTest Reports

R

E322481 UL Conformance Certificate

Tensile Strength test report

Stripping Test report


Bending Strength Test report

Coating Thickness test report

Current Carrying capacity test report


Used for joining two rods

Deep earth electrode system

Good rod to rod contact (tight fit)

Preferred to Threaded ones

N li ibl R i t

Compression Couplers

R

E322481

LORESS


Negligible Resistance

Higher Current carrying capacity

Durable and reliable

Percussion strength of min 200N .

CPRI + tested 23 kA for 1 second



Resistivity Test Report

Compression Test Report

Earthing Enhancing Compound

TestReports&Approval:CompliesBSEN/IEC501647

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pH Measurement Test report

Solubility in acidic environment Test report

Leaching of Fe Cu Zn Ni Cd Co Pb Test Report

Sulphur Determination Test Report.

Environmental Safety (RoHS) Test Report.

Pollution Control Board Certificate

2/2/2011

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McMLEarthing&BondingSystemEarthing Enhancing Compound LORESS


HighVoltage/CurrentTest


McMLEarthing&BondingSystemElectrodeSurroundedbyEarthEnhancingCompound LORESS


McMLEarthing&BondingSystemLORESSHorizontal Earthing or Ring Earthing

McML Protection Technologies Pvt Ltd67 2February20112Feb1167


Permanent Joint Durable and Reliable Corrosion Free

Exothermic Weld Connections LORESS


Offer no resistance High Current Capacity Tested at CPRI

. The best choice where safety, reliability, current carrying capacity and longevity are critical.


2/2/2011

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McMLEarthing&BondingSystemEarth Chamber LORESS


A300X300X300mmPrefabricatedconcretebox

2Feb1169


50 200

100

200

Concrete Cover250x250x25mm

Cement concrete Chamber

300 300 300

Inspection chamber

EBB

Stainless steelBolt and nut

Exothermic Weld

Insulated twin 35 sq mmcopper cable

300x25x6 mm Cu Bus Bar mounted on wall with insulated studs Handle for lid

50

RDSO/SPN/197 : 2008 LORESS


ConducreteEEC

10(3000 mm) x (17.2 mm)Copper bonded MS Rod

300x300x300 mm

Augured Hole length 6 to 8 feet with 4 to 6 Dia

Natural Soil



50 200

100

200

ConducreteEEC

Concrete Cover250x250x25mm

Cement concrete Chamber

300x300x300 mm

Inspection chamber

1.8

M m

inim

um

EBB

Stainless steelBolt and nut

Exothermic Weld

Insulated 10 sq mmcopper cable

300x25x6 mm Cu Bus Bar mounted on wall with insulated studs Handle for lid

50


February71 2 February 201

EEC

6(1800 mm) x (17.2 mm)Copper bonded MS Rod

Compression Coupler

1.8

M m

inim

um

Augured Hole length 6 to 8 feet with 4 to 6 Dia

Natural Soil

McMLEarthing&BondingSystemLORESSRing Earth or Earth Grid

McML Protection Technologies Pvt Ltd2February20112Feb1172

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Conventional Earthing

LORESS Maintenance Free Earthing

GI / CI Pipes Corrosion

Shallow Earth Electrode 8-10 feet

Copper Bonded Steel Rods

Adequate copper bonding 254 MicronsInadequate Galvanization ( 60-80 microns)

Deep Earth Electrode upto 40 feet

Doesn't touch the natural soil Greater contact with natural soil & moisture


Inconsistent resistance

Corrosive agents - salt, charcoal are used

Nut & Bolts loose or corroded

Installation requires more space

Short life 2 to 4 years

Consistent resistance

No corrosive agents are used.

Exothermic Welding - Permanent

Installation requires less space

Maintenance required Maintenance free

Long life 25 30 years

Doesn t touch the natural soil Greater contact with natural soil & moisture

2February2011

McMLEarthing&BondingSystemBS /EN50164-7

EEazyazyEEartharth Salient Features :

highlyconductiveofferlargerconductivesurfacearealowertheearthresistanceby3040%offerlessseasonalvariationsinOhmic valueofferlowersurgeimpedancecorrosion Proof

LORESLORESSS EEazyazyEEartharth AnInnovativeMaintenanceFreeEarthingSystemfromMcML


corrosionProofTheftProofhomogeneousandStablehygroscopicmaintenanceFreeenvironmentallySafesuitableforallterrainlastlong 25yearseasytoinstall

2Feb1174

McMLEarthing&BondingSystemBS /EN50164-7

EEazyazyEEartharth Applications :

RailwayCommunication&SignallingEquipment Computer&DataProcessingCenters, BankATMs

LORESLORESS S EEazyazyEEartharth AnInnovativeMaintenanceFreeEarthingSystemfromMcML

concrete Chamber300x300x300 mm

EazyEarth


LightningProtectionSystems TelecomTowers&Microwaveantennas Transmission&DistributionSystems, OilRefineries&PumpingStations. AllFactories EquipmentBodyEarthings. Residential&CommercialBuildings

LORESS RFC 25

yElectrode

2Feb1175


Approved by

GROUNDINGANDBONDINGEQUIPMENT(KDER)

LORESS TMA complete Maintenance Free Earthing System

McML Protection Technologies


Approved by

FILE NO. E322481

Underwriters Laboratories Inc

R

E322481

2Feb1176

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Tested by

McMLTMLORESS

A complete Maintenance Free Earthing System

Protection Technologies


CentralPowerResearchInstitute,BangaloreShortTimeCurrentCapacity

23.25 kA RMS 1.05 sec & 44.90kA peak

Report No. SC 07424A2Feb1177


McMLStrengths DesignExpertise WellTrainedProfessionals SuperiorinQuality.asperUL/IEEE/BS/IS


StronginSourcing TimelyDelivery Execution:SkilledManPower


McMLEarthing&BondingSystemProfessional & Skilled Staff


McMLEarthing&BondingSystemMAJORCUSTOMERS


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McMLEarthing&BondingSystemBeware!

Spuriousandsubstandardproductsinthemarketeg. Pipe in Pipe or Flat in Pipe or any other Chemical earthingsystems being promoted in the name of Safe Earth Electrode or


systems being promoted in the name of Safe Earth Electrode orMaintenance Free Earthing have no relevance to any national orinternational standards.

2Feb1181

McMLEarthing&BondingSystemSubstandardproductsinthemarket


PipeinPipeElectrodeafterTwoYears

CopperBondedRodafter10years

2Feb1182


Any?LORESS


y

2Feb1183


Thank You


For further information please contact:

Mr T N RaoVice President TechnicalMob : +91-9704456808

McML Protection Technologies Pvt Ltd42, Vijaypuri Colony, Sainikpuri, HyderabadTel : +91-40 -4002 1604

Fax : +91-40-4012 [email protected]

electrical earthing and bonding system

Documents

earth ieee standard

earthing ieee standard

ieee guide

ieee recommended practice

2feb113 earth resistance

recommended guide

bonding equipment bs

grounding ofindustrial