effect of bio-degradable recycled material based soil...
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i
EFFECT OF BIO-DEGRADABLE RECYCLED MATERIAL BASED SOIL
ADDITIVE FOR GROUNDING RESISTANCE IMPROVEMENT
SALEM MGAMMAL AWADH NASSER AL-AMERI
A thesis submitted in partial
fulfillment of the requirement for the award of the
Degree of Master of Electrical Engineering
Faculty of Electrical and Electronic Engineering
Universiti Tun Hussein Onn Malaysia
DECEMBER 2015
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Specially dedicated to my beloved father, mother, brothers and sisters.
Also, dedicated with grateful to Uncles Kaleb Al-Ameri, Hamoud Al-
Ameri and their family. To my friends and classmates I say thank you so
much...
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ACKNOWLEDGEMENT
ل المسلمين العالمين ﴿162﴾ ال شريك له وبذلك أمرت وأنا أو ربه قل إن صالتي ونسكي ومحياي ومماتي لله
In the name of Allah foremost, all prayers, work, life and death to Almighty
ALLAH, Whose give me strength and perseverance to make me able to complete this
master degree, Firstly, I would like to express my heartily thankfulness to my project
supervisor, Professor Dr. Hussein Bin Ahmad for all the guidance and advices given
along this project.
I would like to express my honest thanks to all my family members for their
love, encouragement, prayers and motivations throughout the years of my study. I am
deeply and forever indebted to my parents, uncles and my sister for their
unconditional support, both financially and intellectually throughout my entire study.
Without them I could not finished my study. I would like to truthfully acknowledge
the help and the moral support of all those who support me to complete my study.
Last but not least, my great appreciation dedicated to my entire friends that
always give me a moral support to complete this project. I also would like to thank
Hussein Saleh and Muhib Hamood support and trust me that I was able to complete
this project. Not forgotten, my classmate Mahmood, Malala for support. Thanks to
tanjung bin power station Eng. Mohamed Salah Aldeen and Ibrahim for providing
coal ashes and palm oil waste respectively.
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ABSTRACT
The main propose of this project is to study the effect of various bio-degradable
recycled waste materials to improve soil resistivity ρ in grounding system. Also, it is
to come up with new additive biodegradable waste materials which are not affecting
the environment. The new additive materials are easy to get and safe in term of touch
or use in hands. The previous grounding enhancement materials such GEM causing
problems to the environment such pollution or destroy plants. That is because; it has
a high amount of salt and carbon. In this project, it is going to design and construct
five AC substations models, aluminum grid 1m2 with 0.5m depth for testing new
earth enhancement materials HASA “new additive materials” then compare with the
commercial ground enhancement material "GEM". In addition, it is using a research
area for the experimental activities. HASA materials are going to be formed and
treated to be effective for long time and easy to maintenance. It is to use FOP three
point methods for electrode resistance measurement. Also, the measurement will be
taken in different weather condition, to study the effect of weather on electrode
resistance. This project is providing new additive materials with high performance
and low electrode resistance to get perfect grounding system. HASA gives low
electrode resistance as soil additive and high performance. New HASA materials are
low expensive beside that the availability of the materials.
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ABSTRAK
Tujuan utama projek ini adalah untuk mengkaji kesan pelbagai dimusnah kitar
semula bahan buangan untuk memperbaiki resistivity tanah di grounding sistem.
Selain itu, ianya datang dengan aditif terbiodegradasi sisa bahan-bahan baru yang
tidak akan menjejaskan alam sekitar. Bahan-bahan aditif yang baru adalah mudah
untuk didapati dan selamat dari segi sentuhan atau penggunaan di tangan.
Peningkatan grounding sebelum ini seperti bahan permata menyebabkan masalah
kepada alam sekitar seperti pencemaran atau kemusnahan tumbuh-tumbuhan. Ini
adalah kerana ia mempunyai jumlah garam dan karbon yang tinggi. Dalam projek
ini, rekaan bentuk dan pembinaan model stesen pencawang AC lima, aluminium grid
1m 2 dengan 0.5m kedalaman bagi ujian bahan peningkatan bumi baru HASA
"bahan-bahan aditif baru" akan dihasilkan dan perbandingan akan dibuat dengan
bahan pengukuhan tanah komersial 'Permata'. Di samping itu, ia akan digunakan di
dalam bidang penyelidikan secara eksperimen. Bahan-bahan HASA akan dibentuk
dan dianggap berkesan untuk jangka masa panjang dan mudah untuk di
selenggarakan. Ianya menggunakan kaedah tiga titik FOP untuk pengukuran
rintangan elektrod. Selain itu, bacaan ukuran akan diambil dalam keadaan cuaca
yang berbeza, dimana ianya bertujuan untuk mengkaji kesan cuaca rintangan
elektrod. Projek ini menyediakan bahan-bahan aditif yang baru dengan prestasi tinggi
dan rintangan elektrod yang rendah untuk mendapatkan sistem hentakan yang
sempurna. Bahan HASA yang baru memberikan rintangan elektrod yang rendah
sebagai tanah aditif dan berprestasi tinggi. Bahan-bahan HASA baru tidak mahal
berbanding dengan kewujudan bahan-bahan tersebut.
vii
CONTENTS
TITLE i
DECLARATION ii
DEDICATION iii
ACKNOWLEDGEMENT iv
ABSTRACT v
ABSTRAK vi
CONTENTS vii
LIST OF TABLES x
LIST OF FIGURES xii
LIST OF ABBREVIATIONS xiii
LIST OF SYMBLOS xiv
LIST OF APPENDICES xv
CHAPTER 1 INTRODUCTION 1
1.1 Project Background 1
1.2 Problem statement 3
1.3 Project Objectives 4
1.4 Project Scope 4
viii
CHAPTER 2 LITERATURE REVIEW 5
2.1 Introduction 5
2.2 Fundamental Concept of Grounding 6
2.3 Step and Touch Potential 6
2.4 Tolerable potential difference at a location 8
2.5 Body Resistance 9
2.6 Soil Moisture 11
2.7 Metal for the grounding conductor 13
2.8 Maintenance of grounding stations 14
2.9 Soil Breakdown 14
2.10 Soil Temperature 15
2.11 Soil Resistivity 16
2.12 Grounding Enhancement Materials GEM 18
2.13 Low Resistive Materials LRM 19
2.14 Environment Pollution 20
2.15 Types of soil 21
2.16 Palm Oil Waste 22
2.17 HASA Materials 23
2.18 Coal Ashes 23
2.19 Cement Industry 24
2.20 Related Work Review On the Additive Materials 25
2.20.1 Prediction of soil resistivity and ground rod
resistance for deep ground resisrance 25
2.20.2 Decreasing of ground resistance by deep ground
well method 26
2.20.3 Optimum design of substation in a two layer earth
structure 28
2.20.4 Optimized pit configuration for efficient
grounding of the power system in high resistivity
soil using LRM 28
2.20.5 Efficient use of low resistive material for
grounding resistance reduction in high soil
resistivity area 29
2.20.6 Development of low resistivity materials for
grounding resistance reduction 30
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2.20.7 The Bio-Degradable Recycled Study “similarities
and differences” 30
2.21 Summery 31
CHAPTER 3 METHODOLOGY 32
3.1 Introduction 32
3.2 Overall Methodology 33
3.3 Construction of Grounding System 35
3.4 Measurement Methods 38
3.5 Ph, Moisture Level Measurement 42
3.6 Result Monitoring 42
3.7 Summary 43
CHAPTER 4 RESULTS AND ANALYSIS 44
4.1 Introduction 44
4.2 Ph Measurement 45
4.3 Palm Oil Analysis 46
4.4 Designed HADA Results 49
4.5 Designed HASA Results 56
4.6 Data Analysis 61
4.7 Summary 62
CHAPTER 5 CONCLUSION AND RECOMMENDATION 63
5.1 Conclusion 63
5.2 Problems and difficulties 64
5.2 Recommendation for Future Research 64
REFERENCES 66
APPENDIX A 69
APPENDIX B 72
APPENDIX C 75
x
LIST OF TABLES
2.1 Comparison between grounding metals 13
2.2 HASA additive materials developed to replace GEM 23
3.1 Steps followed for installation materials 37
3.2 4-way Analyser for pH value and Moisture level 42
4.1 The measurement of PH for the grounding system 45
4.2 The moisture measurement of the grounding system 46
4.3 Palm Oil Analysis 47
4.4 Reading for the grounding system 7 May 2015 50
4.5 Reading for the grounding system 12 May 2015 50
4.6 Reading for the grounding system 17 May 2015 51
4.7 Reading for the grounding system 14 May 2015 51
4.8 Reading at 21/05/2015 measurement 51
4.9 Reading at 25/05/2015 measurement 52
4.10 Reading at 08/06/2015 measurement 52
4.11 Reading at 15/06/2015 measurement 52
4.12 Reading at 07/09/2015 measurement 53
4.13 Reading at 14/09/2015 measurement 53
4.14 Reading at 21/09/2015 measurement 53
4.15 Reading at 28/09/2015 measurement 54
4.16 Reading at 26/11/2015 measurement 57
4.17 Reading at 29/11/2015 measurement 57
4.18 Reading at 01/12/2015 measurement 57
4.19 Reading at 06/12/2015 measurement 58
4.20 Reading at 08/12/2015 measurement 58
4.21 Reading at 10/12/2015 measurement 58
4.22 the total average results 59
4.23 Table 4.23 the different between HASA and HADA 60
xi
LIST OF FIGURES
2.1 The different between step and touch potential 7
2.2 Step and touch circuit 7
2.3 Limits of touch voltages as a function of time 10
2.4 Reduction factor Cs 11
2.5 The types and lightning strikes and its effects 12
2.6 The breakdown in soil positive and negative shows 15
2.7 Soil drying curve 16
2.8 Effect of moisture content, temperature and salt 18
2.9 Ground Enhancement Material package 20
2.10 The two different of coal ashes 24
2.11 Cement to max with the additive materials 25
2.12 The deep ground well decrease the grounding resistance 27
3.1 The block diagram of project process 33
3.2 The flow chart to the project progress 34
3.3 The system design 35
3.4 hummer which have been used in digging 36
3.5 The grounding system assembly 36
3.6 HASA installation process 36
3.7 mixes and preparing HASA 37
3.8 Last step tamp down the soil 38
3.9 The PH and moisture measurement 39
3.10 The connection of the resistance measurement 39
3.11 fall of potential method of measurement 41
3.12 Ground Electrodes 41
3.13 Ground Electrodes (62% Method) 41
4.1 Ph and moisture measurements method 45
4.2 Palm Oil analyses 48
4.3 Additive soil improvements 48
4.4 The results of HASA new additive materials 55
4.5 ground systems resistance result 56
xii
4.6 The results of HASA new additive materials 59
4.7 The lowest electrode resistance additive materials 59
4.8 HASA results representing different weather 60
xiii
LIST OF ABBREVIATIONS
HASA - Hussein Ahmad Salem
LRM - Low Resistive Materials
GEM - Ground Enhancement Materials
FOP - fall –Of- Potential
AC - Alternate Current
Ra - For the reading Number
HADA - Hussein Ahmad Daryl
PO - Palm Oil
DCK - Decanter Cake “Palm Oil”
BA - Boiled Ashes
SLB - Sledge Peat
FA - Fly Ashes
BA - Bottom Ashes
xiv
LIST OF SYMBOLS
Ω - Resistance
ρ - Soil Resistivity
φ - Function for Soil Resistivity
m - Meter
V - Voltage
I - Current
A - Distance between Adjacent Rods – m
A - Grounding Area – m2
Rg - Grounding Rod Resistance - Ω
xv
LIST OF APPENDICES
APPENDIX TITLE PAGE
A Flow Chart 69
B Calculate part 72
C Paper format 75
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CHAPTER 1
INTRODUCTION
1.1 Project Background
In this project thesis, it is going to have a clear idea on the grounding system
properties. First of all, grounding system is very needed for safety and protection.
The main reason of grounding system is to protect people, structures and equipment
from unintentional contact with energized electrical lines. Also, the grounding
system must ensure maximum safety from electrical system faults and lightning
strikes “over voltage”. A good grounding system must have a lowest electrode
resistance to allow the current fault pass through, that related to the proper design, in
addition to the materials used and soil resistivity. Continued or periodic maintenance
is aided through perfect design, choice of materials and proper installation techniques
2
to ensure that the grounding system resists deterioration or inadvertent destruction.
Therefore, minimal repair is needed to retain effectiveness throughout the life of the
structure [3].
The parameters which have to be concerned for the grounding system are
personal safety by power system grounding, equipment, building protection and
electrical noise reduction which can be avoided with installation of grounding
electrical equipment and lightning strikes protection. Studying for long time the
effect of the materials used in grounding system and analysis need to have wide
background knowledge of soil characteristics, compositions and grounding
connections and terminations and grounding conductor materials “earth electrode”.
The soil has a complex and difference of substances, solid, liquid and gas
components. The solid phase of normal soil includes minerals and organic matter;
such solid phase means the water solution and gas phase which is the air between the
solid parts of the soil. The conductivity of the soil is determined by the water states,
according to the distance between solid particles and the electrostatic force received
from solid parts. Compositions and grounding connections and terminations have to
be designed according to the application and it is strong when the mashes are too
much so, it can reduce the resistivity of the system [1].
As early as the nineteen century, it was thought that soil would behave non-
linearly when subjected to high transient current. Towne in 1928 publish his work on
driven rods. Discharge current with a rise time of 20-30 micro second and peak
current of up to 1500A were used. It was observed that the V-I curve formed loops
and the resistances under impulse conditions were lower then 60-cycle values. He
ascribed the difference to the associated to the sparks, which expanded the
conducting contacts between the earth electrodes and the conducting soil.
Grounding conductor materials “earth electrode” is the main part of the
project. The additive materials and size of the conduction play the important role of
the grounding system effectiveness. Knowledge on the use of conductor material,
types of earth electrode and different mix hare of materials give substantial
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improvement of grounding system. There are three main materials processing the
suitable conductivity for grounding system; copper, aluminum and steel [1].
Soil resistivity is different from one place to another. It depends on the
climate and humidity of the place; also it is different from part to another part in the
same country sometimes. To have excellent soil conductivity it should be treated
using low resistive materials LRM.
Low resistivity material LRM is a common method in reducing the ground
electrode resistance of the grounding system and improves the conductivity of the
soil. Chemical treatment is about adding to the soil some form of chemical
substances and thus reducing the grounding resistance. LRM is adding low resistive
material to the grounding system surrounding high resistivity soil. The replaced of
high resistivity local soil with LRM can result in reduction in ground electrode
resistance [4].
1.2 Problem Statement
Lightning strikes and flashes activities “overvoltage” are almost every second in
raining season. There are about hundreds of lightning strike to ground in a second.
Lightning flash density caused economical problem, lost in building, structures
damage, interruption of power supply and communication breakdown. The problem
to the scenario is about ineffective grounding system.
Geologically, the soil resistivity is not the same throughout the world; same
paints are rocky and desert. In the high resistivity soil the use of low resistive
materials to improve the ground electrode resistance. Enhancement of the local soil
with the use of chemicals such salt and carbon, leads to many environment problems.
4
1.3 Project Objectives
This project leads to new innovations by using product generated from various
sectors;
i) To study the effect of the biodegradable recycled waste materials on
the ground electrode resistance reduction by the mend technique of
grounding system surrounding soil.
ii) To come up with new earth enhancement materials named as
“HASA” to replace the commercially available ground enhancement
materials GEM.
1.4 Project Scope
The project is executed in accordance to the followings:
a. The site for the experiment is in UTHM RECESS research center
compound.
b. Five pits grounding electrode system, where three test sample
grounding materials are tested, one pit use local soil and one pit use
GEM
c. Fall of potential method (FOP) will be used to measure the resistance
of ground electrodes grounding system.
5
CHAPTER 2
LITERATURE REVIEW
2.1 Introduction
Grounding system role is to give a protection during fault of current or lightning
activity. Also, It is important such as to provide low impedance current path when
fault happen. For that, improving grounding systems is very important. So, some
researches are going to be discussed and compare in this section. Also, it is going to
study and analysis the items included in this research for example soil, electrode
selection and backfill. Specially, the grounding additive materials are going to be
reviewed throughout this section.
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2.2 Fundamental Concept of Grounding
Grounding is provided to connect some part of electrical equipment and installations
or the natural points of a power system to the earth. This provide dispersing paths for
fault current and lightning current in order to stabilize the potential and to act as a
zero potential references point to insure the safe operation of the power system,
electrical equipment and people. At this part, it verifies that grounding system is
generally to make the safety to two main parameters; personal safety and equipment
protection [1].
2.3 Step and Touch Potential
When a fault current flows in to earth through the tower grounding device, the
ground potential in near to the tower is rises. In figure 2.1 if someone stands by the
tower, step potential is passing the current fault from one leg to another and become
conductor. But touch potential is passing the current when touch the tower from the
hand and through legs to ground.
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Figure 2.1 the different between step-touch potential
The step and touch potential caused stop birthing, also an electric shock
accident can be simulated by the equivalent circuit which caused by the human body
with ground. In order to protect operators or other people the step voltage near to the
tower or any current fault and the touch voltage which determine by the ground
potential rise, the soil resistivity and grounding device must be limited to the
allowance level. [18].
Figure 2.2 Step and touch circuit
Step potential:
I x Rg (2.1)
Rg : Ground grid resistance
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2.4 Tolerable potential difference at a location
The potential difference in a ground conductor at any point where a human body may
come into contact with it during the course of a ground fault should be such that the
resultant current through the human body will remain within these tolerable limits.
Step voltage, Es This is the difference in the surface potential to which a
human body may be subject when bridging a distance of 1 meter on the conducting
ground through the feet without being in contact with any other conducting grounded
surface Figure 2.1 The safe step voltage, Es, should not be more than the total
resistance to ground through the body, R2fsb x safe body current, Ib, as a function of
time, where:
R,fsb = 6 . Cs. ρs + 1000 Ω (2.2)
Ib = t
116.0 For a 50 kg body (2.3)
t
116.0 For a 70 kg body (2.4)
𝐸𝑠50 = (6 ∙ 𝐶𝑠 ∙ 𝑝𝑠 + 1000)𝑥 0.116
√𝑡 For a 50 kg body (2.5)
𝐸𝑠70 = (6 ∙ 𝐶𝑠 ∙ 𝑝𝑠 + 1000)𝑥 0.116
√𝑡 For a 70 kg body (2.6)
Touch voltage (Et) this is the potential difference between the ground
potential rise (GPR) and the surface potential at a point where the person is standing
on the conducting ground with one hand in contact with a conducting grounded
surface figure 2.1. The safe touch voltage, Et should not be more than the total
resistance to ground through the body, R2fps x safe body current, Ib, as a function of
time, where:
R2fsb = 1.5. Cs. ρs + 1000 Ω (2.7)
9
𝐸𝑡50 = (1.5 ∙ 𝐶𝑠 ∙ 𝑝𝑠 + 1000)𝑥 0.116
√𝑡 For a 50 kg body (2.8)
𝐸𝑠70 = (1.5 ∙ 𝐶𝑠 ∙ 𝑝𝑠 + 1000)𝑥 0.116
√𝑡 For a 70 kg body (2.9)
Ground potential rise (GPR) this is the maximum voltage that a station grounding grid may
attain relative to a remote ground on route to the grounding network considered to be at the
potential of the remote ground.
GPR = Ig . Rg
Where: Ig = fault current through the grounding grid
And Rg = grid resistance at the station grounding grid
2.5 Body resistance
The proportion of the leakage current through a human body will depend upon the
resistance of the body compared to the resistance through the ground. To determine
the likely body current it is therefore essential to determine the average body
resistance.
a = resistance hand to hand = 2300Ω
b = resistance hand to feet = 1130Ω
c = resistance between the two feet =1000Ω
It is observed that the body's resistance diminishes at higher voltages, above 1
kV and currents more than 1A, passing through the body, and due to a puncture of
the skin tissues. For all safety measures and ground design consideration, the average
human body resistance is considered universally, as 1000 Ω which has yielded
satisfactory results.
10
Figure 2.3 Limits of touch voltages as a function of time
To determine the total resistance of the ground circuit through the human body, the
following may be adopted on:
R2fs = resistance between the two feet in series
R2fp = resistance between the two feet in parallel
There are many formulae to determine the above, all leading to almost the same
results. The most adopted, assuming a layer of crushed rock (gravel) over the ground
surface, is expressed by:
R2fsb = 6 x Cs x ρs +Rb
= 6 x Cs x ρs + 1000 Ω (2.10)
R2fsp = 1.5 x Cs. ρs + Rb
= 1.5 x Cs.xρs + 1000 Ω (2.11)
Cs = reduction factor the nominal value of surface layer resistivity, corresponding to
a crushed rock layer of thickness h, and a reflection factor k.
11
Figure 2.4 Reduction factor Cs as a function of reflection factor K and thickness of
crushed rock (gravel) hs
Where:
K=s
s
, ρ = ground resistivity in Ωm, ρs = Crushed rock resistivity in Ωm
2.6 Soil Moisture
The amount of water associated with a given volume or mass of soil ("soil water" or
"soil moisture") is a highly variable property. It can change on time scales of
minutes to years. However, most soil properties are more stable, and should be
referenced to dry soil weight.
12
Drying a soil to constant weight at 105°C (sometimes 50-80°C for plant tissue)
is the traditional method of arriving at a “dry” sample weight. This temperature is
somewhat arbitrary, and clay minerals in particular may contain 10-15% water (dry
basis) at 400°C (Gardner 1986). As temperature increases, first water in soil pores
evaporates, then water adsorbed to mineral surfaces, followed by water between
lattice layers and that which forms part of the mineral lattice itself. The exact
quantities and patterns of release in a heterogeneous mixture like soil depend on the
particular mix of minerals making up a sample. Water adsorbed to organic
components (as well as other volatile organic substances) will also evaporate over a
range of temperatures. The key point is to specify the temperature used when
reporting moisture data.
Water, especially when it contains dissolved ions, conducts electricity. This
fact can be used to derive a relationship between soil water concentration and
electrical conductivity. Two wires are embedded in a block of gypsum, nylon, or
some other porous material. The block is buried in the soil at the desired depth and
is allowed to come to equilibrium with the soil water (which may take days or
weeks). A voltage is applied across the free ends of the wires (usually an alternating
voltage, to prevent charge polarization of the two electrodes), and the resulting
current is measured to indicate resistance (the inverse of conductivity). Precision is
low at both the very wet and very dry ends of the scale, and the block may not be
truly in equilibrium with the soil water. Gypsum blocks deteriorate with time, but
they do supply a steady source of ions which may swamp out variations in soil
salinity due to fertilization or irrigation practices [24].
13
2.7 Metal for the grounding conductor
Copper, aluminum, steel and galvanized iron are the most widely used metals for the
purpose of grounding. Choice of any of them will depend upon availability and
economics in addition to the climatic conditions (corrosion effect) at the site of
installation. In Table 2.1 we provide a brief comparison of these metals for the most
appropriate choice of the metal for the required application. The ground conductor
can be of aluminum, GI or copper, as discussed earlier. A humid or a chemically
contaminated location is corroding in nature. Aluminum has a rapid reaction and is
fast corroding. At such locations, use of GI or copper conductor would be more
appropriate.
Table2. 1 Comparison between grounding metals
No.
Characteristics
Copper Aluminum Steel Galvanized
iron
Conductivity (%) 100 61 30-40 8.5
Resistance to
corrosion
High. Being
cathodes with
respect to other
ground metals,
this may be
buried in the
vicinity.
It is less corrosive and
highly conductive,
compared to steel or steel
alloys it is preferred
Corrosive.
Copper-clad
steel may be
used to
overcome this
deficiency
High, and is
extensively
used for
ground
connections
and grids
Approximate cost
considerations %
100 50 10 15
14
2.8 Maintenance of grounding stations
To ensure that a grounding station has not deteriorated and its ground resistance has
not increased due to soil depletion it is mandatory to carry out a few checks
periodically to ascertain the resistance of the grounding station. If the ground
resistance is found more than it was designed for, it is possible that by proper
moistening of the soil or by adding more salts or chemicals to the grounding pit, the
desired level of ground resistance is achieved once more. If not, then additional
grounding stations may have to be installed to obtain the original level of the ground
resistance.
2.9 Soil Breakdown
When the current density is high enough, the breakdown starts from the soil near the
grounding conductors in the place the electric field in the soil around the grounding
conductors exceeds the initial breakdown electric field and continues up to the points
at which the electric field drops to lowest electrical value. Moreover, arcing appears
which produce tracking along the irregular surface of soil grains. This tracking grows
as the current density increases. At the same time, the soil resistivity decrease as the
electric field increases.
15
Figure 2.6 the breakdown in soil positive and negative shows
When the current density continuous to increasing, the soil is punctured by the
tracking and a spark over or an arc is generated, which make the soil resistivity very
low, and sometimes it is assumed to be zero. The potential gradient in the arc
discharge region is small. All this study many years ago, the phenomena that the soil
resistivity dropped when large impulse current was observed. This help to decrease
the grounding resistance and decrease the transient potential rise in the grounding
device [1].
2.10 Soil Temperature
Soil temperature is simply the measurement of the warmth in the soil. Ideal soil
temperatures for planting most plants are 65 to 75 F. (18 to 24 C.). Nighttime and
daytime soil temperatures are both important.
The soil thermal resistivity is measured by inserting a heat generating thermal
probe into the soil or soil sample (if done in a lab) and soil resistivity is measured as
described in IEEE Std. 442 “IEEE Guide for Soil Thermal Resistivity” [2] [3]. A
known heat rate in W/cm is injected into the probe and a plot is made of the
temperature of the probe/soil interface versus time. Figure 2.7 shows an idealized
example of the type of curve that may result from this type of test.
16
Figure 2.7 Soil drying curve
2.11 Resistivity of soil (ρ)
The soil resistivity is different from one place to another. The main point of perfect
grounding system is the soil resistivity that will be determined the resistance of
grounding electrode, and the depth measurement that needed to achieve the lower
soil resistivity. All around the world, there are variety of soil resistance that changes
seasonally. The soil resistivity is determined according to their content of electrolyte
that consists of moisture, mineral, dissolved salt and temperature. The dry soil such
as dessert have high resistivity because lack of moisture and dissolved salt.
Measurement of resistivity (ρ) is mainly a function of depth (z). This function can be
written as:
17
)(z (2.12)
The function (φ) is generally not simple and usually used approximation. It is nearly
not possible to obtain best approximation of soil resistivity from measurements on
sample. This is due to samples itself, soil compaction and moisture content can be
differing.
L
A
I
E (2.13)
p = resistivity of soil, (Ω-m), E = applied voltage across the sample (V)
A = cross section area (m2), I = current (A), L = length of the sample (m)
It is recommended that where a grounding station is to be installed, the soil is
tested at nearby locations and an average value of the soil resistivity is determined.
The condition of soil, such as its moisture, content temperature and content of salts
and other minerals has a large bearing on its resistivity. Figure 3.8 illustrates the
effects of such factors on the resistivity of soil. While the temperature of the soil is a
fixed parameter, at a particular location of the grounding station the soil can be
artificially treated to improve the content of moisture and chemical composition, to
achieve a lower value of soil resistivity. It has been found that the resistivity of soil
can be reduced by 15-90% by a chemical treatment.
Figure 3.8 Effect of moisture content, temperature and salt on the resistivity of soil
It is illustrating a normal arrangement of grounding stations with provision for
chemical or salt treatment. The salts used need not be in direct contact with the
electrode.
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The approximate resistance to ground in a uniform soil can be expressed by:
AR
24
Ω (2.14)
2.12 Ground Enhancement Materials GEM
It is a superior conductive material that improves grounding effectiveness, especially
in areas of poor conductivity like rocky ground, areas of moisture variation and
sandy soils. GEM dramatically reduces earth resistance and impedance
measurements. Furthermore, GEM may reduce the size of the grounding system
where conventional methods are unsatisfactory. Once installed, GEM is
maintenance-free, not requiring periodic charging or the presence of water to
maintain its conductivity.
The ingredients of the material are; hydrous aluminum silicates, carbon,
hydraulic cements, mineral dusts, crystalline quartz, deducting oil and sulfur. This is
the commercial material is made in USA and used as in the mast of grounding
systems.
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Figure 2.9 Ground Enhancement Material package
The GEM ingredients:
I. Hydrous aluminum silicates
II. Carbon
III. Hydraulic cements
2.13 Low Resistive Materials LRM
Low Resistive Materials LRM is materials have a high conductivity property. Those
materials are used to enhance some materials to make it more conductive material. In
the past, grounding systems were designed to achieve earth resistances below a
specified value or on a particular density of buried conductor. In some standards,
consideration is also given to the maximum earth potential rise of the grounding
system. Transferred potential levels are another important risk factor which is
associated with presence of metallic objects in an electrical installation.
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In the past, chemicals such as NaCl, MgSO4, CuSO4 or CaCl2 have been
used to reduce the resistivity of the soil that surrounds the electrode. This treatment is
advantageous when long rods are impractical because of rock is strata or other
obstructions to deep driving the rods. [5]
Soil resistivity has a direct effect on the grounding system resistance. In the
areas of high soil resistivity, replacing high soil resistivity by low resistive material
can be used to reduce the grounding resistance. LRM is used to replace the high soil
resistance around the ground device to obtain the low grounding resistance. The
measured grounding resistance of grounding device consists of; lead resistance RL,
ground device conductor resistance RS, contact resistance between the ground device
and soil RC, and current dispersing resistance RD [1].
R = RL+ RS + RC + RD (2.15)
2.14 Environment Pollution of Grounding Chemicals
Ground Enhancement Material (GEM) is a superior conductive material that solves
your toughest grounding problems. It is the ideal material to use in areas of poor
conductivity, such as rocky ground, mountain tops and sandy soil. GEM dramatically
reduces earth resistance and impedance measurements. Furthermore, GEM may
reduce the size of the grounding system where conventional methods are
unsatisfactory [2].
At the same time there is an effect of the GEM for environment, it damage
the planets and life in ground. It is an effective way of reducing the resistivity of
grounding but at the same time it effects the environment.
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Using a biodegradable for grounding is very useful for environment. It is like
the green houses for environment; it is clean, compost and can be modify to have a
GEM to use for grounding system.
2.15 Types of Soil
There are basically three types of soil:
Clay soil, particles are very small and compact. Gardens with these types of soil
particles don’t work well because the air has a hard time getting to the roots. The soil
absorbs and holds water and creates a drainage problem. This adversely affects
healthy root and plant growth.
Sandy soil, particles are large. The water and nutrients (particularly nitrogen)
quickly drain away from the plant root zone. Sandy soil is the opposite of clay soil.
Silt soil is made up of fine particles. Like clay the soil holds water but doesn’t have
good aeration around the roots [22].
Silty soils, these soils are made up of fine particles that can be easily impacted
by treading and use of garden machinery. They are prone to washing away and wind
erosion if left exposed to the elements without plant cover. However, they contain
more nutrients than sandy soils and hold more water, so tend to be quite fertile. You
can bind the silt particles into more stable crumbs by the addition of organic matter.
Loans, these soils are the gardener’s best friend, being a ‘perfect’ balance of all
soil particle types. But even though they are very good soils, it is important to
regularly add organic matter, especially if you are digging or cultivating these soils
every year.
22
Chalky soils are alkaline, so will not support ericaceous plants that need acid
soil conditions. Very chalky soils may contain lumps of visible chalky white stone.
Such soils cannot be acidified, and it is better to choose plants that will thrive in
alkaline conditions. Many chalky soils are shallow, free-draining and low in fertility,
but variations exist, and where there is clay present, nutrient levels may be higher
and the water holding capacity greater.
2.16 Palm Oil Waist
Oil palm is the most important product from Malaysia that has helped to change the
scenario of its agriculture and economy. Lignocellulose biomass which is produced
from the oil palm industries include oil palm trunks (OPT), oil palm fronds (OPF),
empty fruit bunches (EFB) and palm pressed fibers (PPF), palm shells and palm oil
mill effluent palm (POME). Industries of palm oil in Johor produce six types of
waste:
I. Fiber
II. Shell
III. Boiled Ashes
IV. Sludge Peat
V. Decanter Cake
VI. Empty Benches
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2.17 HASA Materials
HASA materials have been developed from biodegradable waste materials to use as
additive to soil in the grounding system to soil resistivity.
Table 2.2 HASA additive materials developed to replace GEM
NO MATERIAL MATERIAL
DESCRIPTION
Tick
1 Palm Oil Waste Boiled Ash
Sludge Peat
Decanter Cake
2 Oil Refinery Sludge
3 Coal Ashes
4 Metal pieces Al
5 Peat Soil
6 Engine Oil
The materials has been marked are included in the new HASA formulas. HASA has
been developed from palm oil waste plus species to make it effective, for example;
Palm oil waste + fly ashes + “Al” partials + Cement + Local soil + Peat soil
2.18 Coal Ashes “Tanjung bin power plant MALAKOFF”
There are two types of coal ashes from tanjung bin power plant. The bottom ash is
mixed with small stones and dust. The anther called fly ashes, very light and gray
color. The two types have been taken for treatment of the soil additive.
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(a) (b)
Figure 2.10 the two different of coal ashes a. Fly ashes b. Bottom ashes
2.19 Cement Industry
The cement industry is one of the most energy-intensive branches of industry.
Portland cement is the most common type of cement in general usage in many parts
of the world, as it is a basic ingredient of concrete, mortar, stucco and most non-
specialty grout. It is a fine powder produced by grinding Portland cement clinker, the
solid material produced by the cement kiln stage that has sintered into lumps or
nodules, typically of diameter 1-25mm at more than 90% and up to 5% minor
constituents. In this project, the cement will be act as hardener for the RRM.
Based on the European Standard EN1971, “Portland cement clinker is a
hydraulic material which consist of at least two-thirds by mass of calcium silicates
(3CaCO.SiO2 and 2CaO.SiO2), the remainder consisting of aluminum and iron-
containing clinker phases and other compounds. The ratio of CaO to SiO2 shall not
be less than 2.0. The magnesium content (MgO) shall not exceed 5.0% by mass [16].