Indian railway&metro rail,others electrical safety first periorty

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Indian Railway S&T Investment High for Safety of Passenger
Indian Railways Invest Rs55,000 Crore for modernization of Signalling &Telecommunication System

Lightening and Surge Protections on Indian Railways, Study of the non-compliance/deviations from
critical instructions /specifications leading to failures. Study and Analysefor possiblereasons for
recent failures due to Bad Weather and Lightning
SAG Professional Course Project Report On Study of Lightning,Surge Protection, Earthing for S&T
InstallationsStudyby Railways and Metro Rail Project Commitee India 6KV and 12KV Earthing Wire Shield to
protect Equipment’ and Human Lives from Electrical Hazards
Need for Lightning and Surge Protections
Sources of Transients and Surges
Effective Protection Plan and Components.
Components of Protection Systems
RDSO and Railway Instructions and Technical Advisory Notes
Provisions in RDSO Specifications
Maintenance Hand books issued by CAM Tech
Typical and Integrated Earthing and Bonding Plan
Common Deficiencies in S&T Installations
Need for Lightning and Surge Protection Systems.
To Protect Equipment’s against build up of High Voltages and subsequent Damage.
To ensure Safe and Reliable working of equipment’s by eliminating induced voltages
To protect the Staff/Personnel working on the equipment’s against shock

Effective Lightning and Surge Protection Plan and Components
Any Protection Plan should be wholistic and should cover the following components. There should not be
any differentiation between Signalling and Telecom systems installed at a station and both should be
integrated.
The lightening strike should be captured at a preferred point referred to as A Class Protection Air Terminal
on Top of the Buildings Effective Down Conductor for diverting the Lightning Energy(High Built up of
Voltage) to the Ground ( Earth).
Effective Earthing Arrangement for dissipating the energy so received. Surge Protection Devices further
referred as SPDs of Class B, C, D as per RDSO specifications.
Ensure an Equipotential Earth Plane for all Equipment’s and Sub Systems.
Bonding of individual Equipment’s to the Equity Potential Earth Plane
Protect Equipment’s from Surges and Transients coming from Incoming Power Lines
Provisions for eliminating/limiting induced voltages to ensure Safe and Reliable working of equipment’s
by Armoring/Screening of Cables carrying low voltage
data and Telecom circuits and their bonding to Equipotential earth.
The laying and drawing of wires/cables with adequate spacing between Clean and Dirty wires to reduce
possibility of induced voltages in clean wires carrying vital circuits due to transients in Dirty wires.
To minimize the effect of circulating Earth Loops

Class B & C Stage 1 and Stage 2 Protection Systems SPDs.
As per RDSO/SPN/165/2012 Class B& C SPDs Stage 1 are required to be provided at the 230 Input level in TT Configuration. The class B are of Spark Gap type Voltage
Switching Device tested as per IEC 61643. Similarly, Class C SPD to be provided between Line and Neutral which is a single compact varistor, a voltage clamping device
and thermal disconnection type. Also, Class C SPDs Stage 2 are provided on the output side for external circuits.
AS per specs the provisions of End-of-Life Indication and Potential Free Contacts are catered as below.
For SPD Class B between Line and Neutral Potential Free Contact to Generate Alarm
For SPD Class B between Neutral and Earth Potential Free Contact to Generate Alarm
For SPD Class C between Line and Neutral Potential Free Contact to Generate Alarm
Approved specifications by RDSO/SPN/215/2018 issue Date 11.02.2018 for IPS under the title “Power Supply Arrangement Level Crossing Gates/Intermediate Block
Working/Intermediate Relay Hut” above features have been made Mandatory for both Class B & C. the same should be made Mandatory for IPS Specifications
RDSO/SPN/165/2012. This will provide opportunity of Prewarning for replacement of a failed SPD.
It was seen at MLYC station that the potential free contacts provided are not accessible for further wiring due to very close interspacing of SPDs It is recommended
that the PF contacts should be prewired and made available on a row of terminals which can be easily accessed and wired to Data loggers.
Another common deficiency/non-compliance of a very important provision of these specs, which is also covered under Earthing specs, TANs, Board letters is normally
seen at installations i.e. “MEEB (Main Earth Equipotential Busbar) shall be installed at 20 Cms to SPD with Connecting cable length being less than 0.5 Meters
without any Bends. “
Location of SPD Box: It is also recommended that the SPD box should be so located on the wall such that there is no cable ladder above it to avoid any incidence of
cables on ladder burning due to any malfunctioning of SPDs causing fire. witness to one such incidence at Mantralayam station of GTL division causing total shutdown
of the Panel.
Use of advanced SPDs and A Class Protection Systems.
With Constant research and innovation, companies are coming up with innovative solutions and constantly improving on their products. However, the efficiency
and effectiveness of such advanced SPDs can only be ascertained over a period of reasonable service and availability of empirical data. Considering the Cost
implications, it is suggested to use them at few Most Lighting Prone Zones.

Earthing and Equipotential Earthing and Bonding Plan. (Follow IS3043(2018),IEEE80(2013)
We would like to give a substantial weightage to this MOST VITAL part of the entire Eco System of Lightening, Surge and Transients Protection Plan as most of the issues here
Fraud
Pertain to installation deficiencies due to unawareness of executing agencies and maintenance officials coupled with use of poor quality of materials/workmanship.
Location of Earth Electrodes:
The earth electrodes should be preferably located in mother soil and not high banks, made-up soil. The distance between two earth electrodes shall be maintained at 3 to 6
meters.
Normally it is desired that the earth electrodes should be provided on either side of the building for Perimetric Earth. To achieve this care and coordination should happen at the
stage of building construction for connectivity across the building at specified locations (same will be explained more clearly in a Typical Earthing Plan). In case it is not possible to
have a Perimetric Earthing a Ring
Earth should be provided on one side of the building for which adequate nonConcrete surface should be ensured to achieve 3 to 6 meters spacing between earth electrodes.
It should be insisted upon and provided for while approving the Building Drawing that a provision of Plinth area of 1.5 Meters on both sides of the building shall not be concreted
to cater for provision of earth electrodes.
Earthing for Equipment’s is not a BOQ it’s Design ,Engineering ,Calcullation of Earth RODs and use of Ground Enhance Compound Earth for Achiving Earthing Value should be
between 0.5 Ohms -1.00 Ohms Should not be Exceed from 2.00Ohms-5.00 Ohms any reason
Electrodes Maintenance Free Copper Bonded Earth Electrode made up of high tensile low carbon steel rod with copper coating on outer surface.
Irrespective above choices, the earth values realized will normally be function of soil resistivity, however it is preferred that for all Earths in station area should be of MF type
simply because of being almost maintenance free and providing lasting connections through exothermic welding for all Burried and Permanent Earthing Connection except for
Testing points Nut Bolt allowed . For outdoor application MF earths are preferred for DAC application since required earth values are <1 ohms.
Ground/Earth Enhance Compound is having Important Role to perform Effective and Maintain Result for Earthing 24X7 365 Days Consiering Life 25Years these Compound should
be Carbon and Lower Resistivity less than 0.02Omic ROHS , No Oxidation and Leaching Free capable to retain Moisture longer surrounding Metal Part called as Earthing ROD
Provision of Loop earths and Ring/Perimetric Earth arrangements
Additional Earth electrodes should be provided at 3 to 6 meters spacing and looped/interlinked with copper tapes and exothermically welded The copper tapes shall be laid at a
depth of 0.5 meters
This copper tape should also be covered with earth enhancing compound
Whenever the distance between an Equipment Room in the same building or a separate building is more than 25 Meters,there should be a separate Earthing System

Concept of MEEB (Main Equipotential Earth Busbar) and SEEB (Sub Equipotential Earth Busbar) and BRC (Bonding Ring Perimetric)
As can be seen in Fig 4 Typical Earthing and Bonding Plan There is a Perimetric Ring Earth with six Electrodes covering the Equipment (IPS) Room and Relay Room of
which One electrode is termed a main electrode.
It can be seen that two Perimetric earthing systems are considered for Signalling and Telecom installations with interconnection for achieving Equipotential Earth
The number of Earth electrodes can be decided based on-site conditions to achieve <1-ohm values.
Separate Earths are catered for Lightning Arrestors, VHF Sets, Quad Cables which are further interlinked with Perimetric Earth to achieve equipotential
Earth.
The Main Electrode alone is connected to MEEB Copper strip in Equipment Room Just below the SPD Box of the IPS. As per recent TAN,
It is to be connected with 4 numbers of 35 Sq mm Copper cables. SEEBs are provided in Each Room directly connected to MEEB through suitable multicore copper
cables.

Each Equipmentshould be directly connected to the SEEB/BRC in Star bondingconfiguration as per picture to avoid circulating Earth loops.
The objective of BRC is to have a low inductance Common Bonding Network. It is not necessary that BRC has to be a closed loop. BRC can be terminated short of
Doors and windows.
Separate SEEB with BRC has been provided in IPS Room, Relay Room.
SEEBs without BRC has been provided in Maintainer and Station Master Room
Other important considerations of Earthing and Bonding Arrangements.
It is preferred that connection to EEBs/BRCs shall be exothermically welded, if not Copper lugs with Spring Washers shall be used.
Copper cables and Tapes of standard sizes shall be used
Routing of all bonding conductors from Equipment’s to SEEB/BRC and SEEB to MEEB shall be as short as possible and separated from other wiring’.
Preferably all bonding connections should be routed through floors except for earthing ladders which should be taken from BRC in a separate PVC pipe and
connected to bottom of ladder.

A Class Protection Systems (Lightning Protection) IEC62305/NFC17-102
As per extant instructions from Railway Board and RDSO A class LPS are to be provided for all Electronic InterlockingInstallations
of the type of Franklin Rod of 3 meters height (TAN 3006) for protection against direct lightningstrikes.
There are three primary components of the A Class systems shown in
Air Terminal
Down Conductor
Earth Grounding System
The Air terminal capturesthe lightningdischarge current which is dissipated to Earth through Down conductor
The Down conductor is a copper cable of adequate size. 50% of the lightning energy is transferred to the ground.
It is seen that there are no standards specified for design, type of Air Terminals and Down Conductor by RDSO. Railways are using
the practices as suggested by Professional and OEM’s
It is recommended that RDSO shall clearly specify the complete Design, Types, Material, ProtectionCoverage for Air Terminals
and Down Conductor through separate Specificationsto have uniformity and control over quality in installations.
Selection of Lightning Protectionand Associate Components shpuld be Tested as per Parameters ,TestReport from Reputed LABS,
Genuine and Right Components as per Application , Equipment’s and Environment Condition Indoor ,Outdoor,Under Ground.
Design ,Engineering and Installationshould be prefer by Professionalsor OEM’s to ensure and Penalise if any Failure and Losses
Damage Cerificate/Letter should be submitt for each installation.
Periodical Maintenance should be on priorty for EffectiveProtection from Lightning

HASANPARTY(HSP) Station Case Study by S&T Failure and Reason for
AS per advice of PCSTE/SCR, HSP station was inspected along with DSTE from HQ of the division, field ASTE and Section SSE and
Technician, to study the possible cause of recent failures due to Lightning and Bad weather along with other deficiencies pertaining
to Lightning Protections, SPDs, Earthing arrangements.
It was seen that the following failures had occurred in recent past
Outgoing TPR 24 V DC fuses at same location box were fused for Track Circuits 29T, 11T, 39T
DN East Line HASSDAC failed and Motherboard burnt
RE Cutting 24 Volts DC Signal circuit Fuse blown at Relay Rack. It is a mid_x0002_section LC Gate with IPS. Same also used for RE
cutting purpose.
Track Circuits failure
The power cable carrying 24 V DC from Cabin to Location box was checked and properly earthed
Signalling cable carrying TPR circuits was properly earthed at Cabin end and cable was meggered and values above 100 M ohms.
The 24 V DC output at IPS was protected with SPD found in working condition At the Location box, it was seen that the power cable
24V DC armour earthing at GI wire was loose and not soldered. Further GI wire was also rusted .
The probable cause of fuse blowing is due to ineffective earthing of
the power cable armour at location end

HASSDAC failure
It was seen that the 24 V DC to HASSDAC was extended from an External DCDC convertor unit (Not from the IPS Modules) which was not protected by SPD
The location end Earthing and armour connectivity was found intact. The possibility of surge coming through Quad cable could not be checked as the system was changed to new
quad cable laid by construction two days before our visit.
It was seen that the HASSDAC motherboard was burnt at the power supply cards area
It was also seen that the West Line HASSDAC supply was extended from DC-DC convertor modules of IPS protected with SPDs hence it was not failing, Only East
Line HASSDAC was regularly failing. The probable cause was non protection of external supply with SPD.
RE Cutting Failure
The RE Cutting for Distant Signal is provided at the Relay Room of a Mid_x0002_section LC gate having
its own mini IPS.
The IPS provided is as per 2004 specifications with external supplies protected by MOVs and not SPDs
RDSO vide its letter No STS/E/IPS. Genl Dated 02.12.2011 had advised Railways for modification by
OEMs for provision of SPDs for all external supplies at pre-specified Rates. It is noticed that the
required modifications were not carried out in this IPS.
The Earth Value at IPS MEEB was found 3 Ohms which is on higher side.
The probable cause of failure was non-protection of 24 V DC external supply by SPD and high earth resistance.
Other deficiencies noticed at HSP station
In both Cabins the MEEB at IPS Room and Relay Room were two separate earths without any interconnection i.e. not having an equipotential earth.
The MEEB for IPS was located in Battery Room and connected to SPD of IPSwith a cable length of 10 to 15 Meters and size 10 sq mm and mixed on ladder with other wiring
The 230 Supply Power cable from CLS panel to IPS was mixed with other wiring and laid on a common ladder.
A single Earth was provided for both side Quad cables without interconnection to Ring Earth
The BPAC and Block circuits were changed over to new quad cable without any earthing of quad armour at other end station KMPT resulting in high induced voltage of 54 Volts.
The quad pairs were not twisted before terminations at either ends.
Many of the outdoor Earths to location Boxes and Signals were hugely rusted and connected with GI wires.

Recommendations for Improvement
The Conventional Earth Electrode
It is normally seen that the conventional earth electrodes, though supplied with RITES inspection, over a short period of time gets rusted. Specially the bracket
to which earth Cable/GI Wire/MS Flat are connected. Same can be seen in figures
Stricter quality checks are required at Inspection Points such that the poor
quality materials are rejected.
It is recommended to change the design of bracket to double brackets as
shown in Picture so that Two parallel connections can be made with Signalling
Cable and MS Flat.
Earthing Lead shall be Mild Steel Flat of size 35mmX6mm or Copper wire of 29 sq mm of cross-sectional area (19 Strands of 1.4 mm dia i.e.
A 19 Core Sigg Cable or more)
It is preferred that exothermic welding be made mandatory for connections to Electrodes.
M S Flat Earthing Leads in addition to copper cable
It is seen that in some theft prone areas copper cables are getting cut and stolen. In such a case if MS Flat earthing is
provided, it will provide the required connectivity and protect the equipment’s.
GI Flats with Nut Bolts and Spring washers for Cable Armour earthing in location Box in place of GI wire
It is generally seen that the traditional way of earthing the cable armours in location boxes with GI wire and
Soldering/Tinkering are prone to Poor and incomplete workmanship, Rusting of GI wire and therefore making the
earthing ineffective inspite of the earth electrode having good earth value. The same was witnessed at HSP station causing fuse blowing.
AS can be seen in the figure 14 The GI flats are drilled with adequate holes for connecting the armours of all possible
cables in the location box besides having a cushion for future connections. The use of spring washers ensures firm
and lasting connection.
Recommendations for change in design of conventional electrodes, MS Flat earthing and GI Flat earthing in Location boxes
may be considered for standard adoption by competent authorities

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Link Vue SystemElectrical Safety (SurgeProtection,Lightning & Earthing )

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Surge Damage Your Systems It’s Serious Topic Let Understand

Awareness,Implementaion&Maintenance of Lightning Protection
along with
Electrical Safety is Medatory to protect Human & Valuavle Assets
Lightning strikes are the biggest natural killers in India, causing more than 2,000 deaths each year, according to the top experts from the IMD and the NDMA.
India has witnessed an increasing death toll and damages due to lightning bolts over the past few years, said Mr.Rajendra Singh, Member, National Disaster
Management Authority (NDMA), while addressing a national-level workshop on the issue organized by the Indian Meteorological Society, Indian Institute of Tropical
Meteorology and National Centre for Medium Range Weather Forecasting.
Cloud lightning Strike is "a serious threat", Mr.Mrutyunjay Mohapatra, the Director-General of India Meteorological Department (IMD), said this happens primarily
due to increased exposure of people, especially farmers, fishermen and labourers who remain outdoors for reasons of livelihood.
Implementation of Lightning Early Warning System and Installation of Lighting Protection System in Buildings, Telecom Towers, High Mast Lightning Poles ,
Transmission and Distribution Towers and specific Location High Rise Buildings is follow as per National and International Documents to Protect from Lightning to
ground as per IEC62395 Conventional as well Effective Advance Lightning Protection(ESE Type) will be safe people and Assets from Lightning and Discharge with minor
or negligible loss if any.
Our Central Govt should declare Effective Installation of Lightning Protection ,Surge Protection and Effective Earthing under necessary Electrical Safety and advise all
Director General Electrical Inspectorate to ensure by Fire and Electrical Safety Inspectors before occupancy Clearance for new Construction and also monitor
Implementation of Proper maintenance to ensure perfect and healthy condition of these product and Installation.
They should also mentioned mandatory of all these Govt , public and private Infrastructure to cover risk under Lightning and Fire with Insurance company 24X7 if not
found and any such incident happening HOD should book in Criminal Office and recover all Human Loss and Customer Assets value from them also the responsible
Fire and Safety inspector and Maintenance HOD of said premises should book under LAW.
The country should have Control Room who can monitor Advance Early Lightning Threat and inform to local now capable of having 'real-time' information about
lightning updated every 5 minutes to alert the people about the potential threats.
Economic losses occur with cultivated fields and buildings, infrastructure like communication networks, power plants and so on, which are often destroyed by
lightning strikes, and occasionally even igniting potentially devastating wildfires.

Advantages and disadvantages of the different Lightning Protection

Surge Protection Installation Important Guidline

Surge Introduction and Equipment’s Failure
• Sources of Surges
• A surge is a transient wave of voltageor current. The duration is not tightly specified but is usuallyless than a few milliseconds.
The following are typical sources of surges:
• Lightning.
• Utility switching,including capacitor switching.
• Equipmentswitching and switchinginductive loads
• within a facility.
• Protectionagainst surges is referred to as surge protection, and includes protection against bothsurge voltages and currents.
The devices used to protect against surges are referredto as surge protectivedevices, or SPDs. A surge of duration longer than
a few millisecondsis referred to as aswell or temporary overvoltage(TOV) and requires a differenttype of protection design;
SPDs can fail if exposed to long duration TOVs.
• Surge Effects
• Surges can cause equipment damage. Large surges damage equipment and other components in the electrical distribution
system.Smaller surges can cumulativelydamage equipment and can causenuisanceequipment tripping. Both surge voltage
and current can be damaging. In the case of
• lightningstrokes, the surge can be carried into a facility via all of the connectedconductive paths.There is a limit on how high
of a voltage can be transmitted into a facility or residence.Above a certain level, a high voltagewill result in flashover in the
insulationsystem of electrical equipment and conductors. A flashover can cause insulationdamage, electric shock, and fire.
• Industry confirmed catastrophic failure or damage of electrical or electronic equipment due to a lightningevent or voltage
surge and premature failure of electrical or electronic equipment,including failure of life safety equipment.

External - Atmospheric Over-Voltage (lightning)

Electrical Safety Mean Lot’s Your Equipment‘s
While in Operationor in Ideal Conditions
We Power all equipment’s and make safe use and protection human from Eletrical Hazard Earthing for Equipment and Body is Important and as per Electrical Equipment Cataugry Earthing Value
is Define in IEEE80 ,IEC62305,NFPA, NEC and NBC2016.
We Generally observe Nutral and Earthing and ensure safe operation of Equipment’s.
Single Phase Line Nutral and Earthing
3Phase Line 1,Line2,Line3 , Nutral and Earthing.
We are witness of Surge Travel into our System from Power Supply ,Ground and Communication Ports .
These Surge reason may be Overvoltages , Transient Voltages or Lighting Direct or through Indirect sources also from Communication Cable .
another reason may be Loose Contact ,Poor Jointing ,Disconnection and Short Circuit.
Reason of Surge and Damage
Advances in technology have caused electronics to become sensitive to voltage impulses,
because :
Most electronics are never totally turned off
Most electronics require a good grounding and wiring system
Many electronics have connections to another cable system, besides power
Most electronics can be damaged by very low-level voltages that get into the circuits
Micro-miniaturization in electronic systems increase sensitivity to transient effect
SURGE PROTECTION SYSTEM Design with Effective Earthing as per IS3043(2018)
Protection of the electrical & electronic equipment againstsurges from lightning strike or other transient effects
Building with a proper lightning protection system will reduce possibilities of induced voltage surges in power or data lines
Design requirement for surge protection will be coordinated with lightning protection system

Surge Protection and Earthing for Rail/Road Tunnels

Surge Protection Applications Selected by Voltage

Reason for Surge and Electrical Entrance Cataugry as per IEC

Surge is Danger Threat It’s Pick-up and Travel to System
Pulse/MicroSec (10/350,8/20&1.2/50) as per UL 1449 and IEC 61643-11
Surge protection devices suppress the excess voltage, divert it safely to the ground and prevents it
from causing any harm. Surge or Lightening Protector is designed to provide Line to Line protection
and Line to Ground protection.
Operating Voltage of the Surge or Lightening protector is greater than the normal operating voltage
of the device or system to be protected.
During the normal operating condition, the Surge or Lightening are non-functional as they provide a
high impedance path between Lines to Ground.

Why Surge Protection Mendatory in Your Electrical Installation

Selection of Surge Protection as per Equipments Location

Surge Protection Installation Guide Line
SPD for power lines
7 module full mode protection
Monoblock type
Not interrupt the system
kA rating determine by the weakest link
Enclosed in rugged,safe, all metal enclosure
Provided with solid state indicators (LED)
Installed in parallel
Design to withstand multiple strikes
SPD for data/signal
Compatible & transparent to existing system
Not interrupt operation system

SURGE PROTECTION SELECTION FOR POWER SYSTEM

SURGE PROTECTION SELECTION FOR PABX SYSTEM

SURGE PROTECTION SELECTION FOR FIRE ALARM SYSTEM

SURGE PROTECTION SELECTION FOR CCTV SYSTEM

SURGE PROTECTION SELECTION FOR NETWORKING SYSTEM

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UL Latest Documentation for SPD Year 2019

Your Answer for Queries of Surge and Lightning
• What is the 10/350 waveform and how is it related to the IEC Class I SPD tests?
• The 10/350 waveform is an electrical impulse produced in a laboratory by a surge impulse generator. The "10" refers to the 10 microseconds it takes the
impulse to reach 90% of its peak current. The "350" refers to the time in microseconds it takes for the impulse to decay down to 50% of that peak. IEC
standards state that this waveform simulates direct lightning and is based on research findings of CIGRE (International Council on Large Electrical
Systems - headquartered in France). As shown elsewhere on this website both of those claims are false. Nevertheless, the IEC Class 1 Test stipulates this
waveform be used to test SPDs which are to protect against direct lightning.
• I've read that the 10/350 waveform is much more powerful than the other waveforms currently used in SPD testing such as the 8/20. If that's true
and only spark gaps can pass those tests, then why do you oppose them? Why wouldn't we want a "stronger" SPD protectingour equipment?
• The mistake we've all made is to think of the 10/350 waveform as a "powerful" impulse. Far more accurately, it should be thought of as an "irrelevant"
impulse. A spark gap protector (because it responds slowly and is a crowbar device) can endure a high amplitude 10/350 waveform but doesn't do very
well protecting electronic equipment from actual lightning. An MOV protector responds 1000 times faster and actually absorbs energy in the process of
clamping the lightning voltage down to safe levels. MOVs don't do so well with a 10/350 waveform because they absorb part of the energy, but they far
more effectively protect electronic equipment from actual lightning. CIGRE's 2013 Technical Brochure 549 has corrected the misconception that the
10/350 waveform is the waveform of a lightning first stroke--because it isn't. That is why it's accurate to call the 10/350 waveform irrelevant. We do
want stronger SPDs protecting our equipment and that's why we consider it disingenuous for standards to treat MOV-based SPDs as second-class
citizens when in fact they are superior at handling direct lightning.
• What is the Lightning Protection Zone system and how is that related to the 10/350 waveform?
• The Lightning Protection Zone (or LPZ) system is a surge protective concept that divides a structure into several "risk zones" nested within each other.
The concept has been around since 1977 when E.F. Vance of the Stanford Research Institute proposed it. Here is a diagram showing Vance's risk zones,
extracted from his 1977 paper "Shielding and Grounding Topology for Interference Control ." By "grounding" the outside of each shield to the inside of
the adjacent shield, Vance sought to control the effect of external surges entering a facility. He also realized the need to limit the surges on the power
and data lines entering the structure. Zone 0 was the external environment liable to lightning strikes. Zone 1 was the area inside the structure.
• Although the purpose of the LPZ system is to mitigate the impact of incoming lightning, practically speaking, the entire function of the IEC LPZ system
has become the regulation of structural and surge protective devices deemed "proper" for use in each zone. IEC international lightning protection
standards adopted Vance's idea, but sabotaged it by interjecting the 10/350 waveform. In the IEC 62305 version, direct lightning (Zone 0) must be
represented by a 10/350 waveform, hence only spark gap "lightning arrestors" which could pass the 10/350 Class I test were allowed to be used in Zone
Zero or at locations bordering on Zone 1 (service entrance locations.) The problems with this approach are documented throughout this web, namely: 1)
the CIGRE 2013 Technical Brochure 549 shows that the 10/350 waveform does not represent actual lightning, and 2) the spark gap "lightning arrestors"
are intrinsically flawed.
• Interestingly, although the IEC-branded LPZ system has been in widespread continuous use for over 20 years, there are apparently no statistical studies
to prove its effectiveness.
• More on the LPZ system can be found here.

Your Answer for Queries of Surge and Lightning
• We have spark gaps installed but sometimes we've noticed that the downstream MOV protectorsburn out or our electronic control systems get
damaged yet the spark gap hasn't registereda surge. What is that?
• In the first case you mention, what's happening is the MOV protectors are responding faster than the spark gaps. That is easy to understand since MOVs
inherently react 3 orders of magnitude faster than spark gaps. If the dinky "Class II MOV arrestors" are rated too low to handle lightning (which is always
the case with the ones used together with spark gaps) then they can and do burn out before the spark gap can react. As to your equipment burning out,
you need to understand that spark gaps may not respond till the voltage level reaches 2.5 kV to 3kV. A transient surge of 2.3 kV is high enough to fry
your electronic equipment but not high enough to trigger the spark gap.
• Was the 10/350 waveform ever a valid lightningparameter?
• Unfortunately not.
• Why has it taken so long to correct this situation?
• You'll have to ask the members of TC 81 about this one. One possible reason is that the 10/350 waveform has always been predominantly a marketing
tool and there were vested interests around making sure it was promoted and stayed in place. People who knew there was a major problem with it
became afraid of speaking out against it. This could be attributed partly to the shy nature of people and partly to all the force that was employed to keep
it going. But these are just opinions.
• Does effective surge protection require 3 stages as the IEC standards state?
• No. The reason the IEC standards required 3 stages was that spark gaps were unable to clamp overvoltages down to safe levels. They therefore had to be
used together with several extra levels of MOV SPDs. A single properly sized MOV-based SPD can itself clamp overvoltages down to safe levels. That isn't
to say you would never use additional stages. In critical installations a second stage is typically used as a safety factor and to handle transient voltages
that are internally created (i.e. created within the facility itself) or appear on the building grounding steel. The best SPD in the world, if installed at the
building entrance, would not be able to forestall damage from the overvoltages of internally-created transients.
• Exaggerated ground resistance values? What does that mean?
• It comes from the predilection of many surge protection companies to The most often heard "excuse" given when spark gaps failed to protect electronic
equipment was "Your 5 ohm ground resistance is too high. You need to get it down to 1 ohm for your surge protection to work." This is another urban
legend. Per Ohms law, (even discounting impedance which can make this situation worse) a 50kA surge going through a 1 ohm circuit will produce a
voltage of 50,000 volts. This is 100 times more than could be withstood by electronic equipment. This only says that no matter how good your grounding
is, to protect electronic equipment requires fast acting efficient surge protectors (which eliminates spark gaps.)
•

I am Power Plug I will be Marry with only My Right Partner
Make you Safety and Comfort

Electrical Power Socket IP Protection Outdoor

Electrical Socket for Indoor and Out Door Purpose

Electrical PLUG & Socket High Voltage IP 68

Electrical PLUG &Socket High Voltage IP 68

Electrical Plug & Socket High Voltage IP 68

I should Design Electrical Installation to Perform My Equipment and Safety
of Mine and Other’s from Electrical Shocks
Earthing Design is Not a BOQ It’s Design New Every Installation Depend on Soil Report
Earthing Value should be Achive and Maintained 24X7 365Days

Earthing is Mendatory and Importance of Perfect Installations
Why the need for Grounding and Bonding
Equipment Protection
Satisfy Warranty Requirement
System Performance
Service Protection
Personnel Safety
Voltage Difference between Two Equipment Earthing below 5 Volts
Earthing Value is below 1.00 OHM for Low Voltage and 0.50 Ohms for
All Other Electronic Sensitive Equipment’s

Earthing for Equipments as per Latest Electrical Safety Indian Standard

Earthing should be Eqavapotentail but use Spark Gap for Insolation

Maintenance Free Earthing Installation

Maintenance Free Earthing Value Calcullation & Costing Per PIT
• BOQ Per Earthing PIT
• 17.2mm Copper Bonded 3 Mtr ROD=1
• Earth Enhance Compound(Value 0.012
Ohm) Qty -30 KG
• Earthing Clamp Connector for
Connecting FLAT STRIP/Conductor - 01
• Earthing Strip /Conductor as per
Equipment Load /Fault Current -10
Mtrs
• High Quality Industrial Plastic PIT Cover

Earthing and Conductor Installation

Platform Touch Voltage Protection Membrane System

Director:- Mr. ManishKhatri
Head Marketing & Sales:- Mr. Mahesh Chandra Manav
Link Vue System Pvt Ltd
Head Office: I-19, Karampura, New Moti Nagar, New Delhi, (India).
Mobile: +91-9811247237
Tel: +91 11 4559778
Email:manav.chandra@linkvuesystem.com Email:manish@linkvuesystem.com Website: www.linkvuesystem.com
Link Vue Systems Pty Ltd
2 BRUCE STREET, BLACKTOWN NSW 2148,
Sydney, Australia Mobile:+61-423064098, Mobile: +91-9811247237,
Email:manav.chandra@linkvuesystem.com
visit webpage www.linkvuesystem.com
50

Indian railway&metro rail,others electrical safety first periorty

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