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Lightning Protection
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Facts about LightningA strike can average 100 million volts of
electricityCurrent of up to 100,000 amperesCan generate 54,000
oFLightning strikes somewhere on the Earth every secondKills 100 US
residents per year
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Lightning Doesnt Go Straight Down
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What Does This Mean?Lightning can strike ground up to ten miles
from a storm (Lightning out of the blue)There is an average of 2-3
miles between strikes
So how can we tell how far away lightning has struck?
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Use The Five Second RuleLight travels at about 186,291
miles/secondSound travels at only 1,088 feet/second
You will see the flash of lightning almost immediately
5280/1088= 4.9About 5 seconds for sound to travel 1 mile
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Stepped Leader
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Streamers
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Benjamin Franklin
memperkenalkan sistem perangkap kilat pada 1752
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Tujuan Perlindungan KilatMengelakkan panahan kilat (strike)
daripada merosakkan peralatan elektrik & elektronikUntuk
bangunan yang melebihi dua tingkatUntuk bangunan tunggal di kawasan
tinggi atau lapangUntuk bangunan atau struktur yang terdedah kepada
ancaman kilat
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Four Main Features of Lightning Protection1) Air terminal
2) Conductors
3) Ground termination
4) Surge protection
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Sistem Perlindungan Kilat1) Horizontal conductor (copper)/
aluminium)2) Down Conductor (copper/ aluminium tape, G.I)3)
Incpection Point/ Test Clamp4) Earth Chamber5) Earth Electrode6)
Air Terminal (copper)
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Air Terminal and Conductors
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Grounding Rod
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Lightning Protection System Accessories
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Lightning Protection System Accessories
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Surge Protection Device
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Surge Protection Device Installation
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Surge Protection Is A Must
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Lightning Protection System Installation
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Lightning Protection System Installation
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Faraday Cage Concept
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LIGHTNING STRIKE
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Lightning Protection System
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Strap FastenerHorizontal ConductorMounting BaseDown
Conductor
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LIGHTNING ROD/ AIR TERMINAL
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DOWN CONDUCTOR FOR GROUND CONNECTION
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PLATE TYPE TEST CLAMPCopper Strap
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Jenis Down ConductorPita tembaga (copper tape) 3mm x 25mmPita
AluminiumG.I Cable
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DOWN CONDUCTOR & TEST CLAMP
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DOWN CONDUCTOR & TEST CLAMP
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GROUND CONNECTION
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GROUND CONNECTION
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Ground ElectrodeThese consist of some form of deeply buried
conductor, since the major earth resistance lies on the top
soilDiscovered by Karl August Steinheil in 1836. Ground can be used
as a return path to complete a circuitBuried copper or galvanized
earth plate have largely given place to threaded copper-clad
steel-cored rods
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GROUND CONNECTION
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GROUND CONNECTIONCadweld Method
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Types Of ElectrodeEarth rods or pipesEarth tapes or wiresEarth
platesEarth electrodes embedded in foundationMetallic reinforcement
of concrete structureMetal pipesLead sheaths or other metallic
covering of cables (especially underground cables)
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EARTH ELECTRODES
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EARTH LOOPS & EARTH DIFFERENTIALSTELECOM GROUNDINGELECTRICAL
POWER GROUNDINGLIGHTNING DOWN CONDUCTOR GROUNDING
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METAL PIPES GROUNDING
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EARTH ELECTRODES
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EARTH CLAMPS
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EARTH PIT/CHAMBER
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LIGHTNING ARRESTOR EARTH
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Earth ResistanceThe earth resistance depends on soil resistivity
and characteristic. The type of suitable for earth electrode
are:Wet marshy groundClay, loam soil, arable landClay soil, loam
mixed with small quantity of sandDamp and wet sand
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Earth ResistanceAchieving a good earth depend on local
condition. There are 3 factors:Moisture content of the soilChemical
composition of the soilTemperature of the soil
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Earth ResistanceIn area of high soil resistivity, it is
difficult to obtain an earth resistance say 1 Ohm or less. Several
option are available in the form of soil conditioning agent e.g
copper sulphate, sodium carbonate, bentonite & marconite
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EARTH RESISTANCE TESTCurrent ElectrodePotential ElectrodeEarth
Electrode
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EARTH RESISTANCE TEST
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PURATA RINTANGAN PADA BUMI
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Rintangan Elektrod Bumi untuk Sistem Perlindungan
KilatMaksima
10 Ohm
Malaysia Standard MS IEC 61024-1-1:2001, Perenggan 2.3.3.1
menyatakan nilai rintangan bumi untuk alat perangkap kilat
hendaklah di bawah 10 .
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Jenis Sambungan Ke ElektrodEarth ClipPlumbed jointBrazing
(copper)Bolt & nut/ socketingExothermic welding (CADWELD/ FURSE
WELD)Cold pressure welding
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EARTH CLIPS
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EARTH TAPE CLIPS
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Tamat....
Awan Cumulonimbus (awan yang membawa hujan) memainkan peranan
dalam kejadian kilat. Disebabkan pergeseran antara udara dan wap
air, awan Cumulonimbus akan mengumpulkan banyak cas negatif dan cas
negatif. Cas negatif akan berkumpul pada bahagian bawah awan.
Permukaan bumi pula mempunyai cas positif. Apabila cas negatif pada
awan Cumulonimbus terlalu banyak, cas negatif tersebut akan
tertarik ke arah cas positif (permukaan bumi) dan ini akan
membentuk laluan ion. Laluan ion akan mencari titik rintangan bumi
yang paling rendah (titik rintangan bumi yang paling rendah adalah
tempat yang paling mudah cas negatif mengalir ke bumi). Apabila
laluan ion menyentuh bumi, satu nyahcas elektrik iaitu kilat akan
berlaku mengikuti laluan ion tersebut. Perlu diingatkan, nyahcas
kilat terbentuk dari bawah ke atas, bukannya dari atas ke bawah.
Ini kerana adalah sifat fizik arus elektrik yang mengalir dari cas
positif ke cas negative.**
