Surge and Lightning Protection
It will never happen to me? Don't you believe it ... Globally, some 2000 on-going thunderstorms cause about 100 lightning strikes to earth each second!! |
Modern day industrial facilities contain large amounts of microprocessor based equipment from control computers to field sensors. High speed data is transferred around a site to allow business decisions to be made which affect productivity and efficiency. The real time data used for such control and decision making would be useless if corrupt and, worse still, the complete loss of such a system due to surges or lightning would impact on productivity and profits.
Much of the industrial equipment is installed in harsh environments, subject to natural disturbances such as lightning and man made disturbances like switching transients from motors, pumps, welding equipment and variable frequency drives. Small transients and disturbances on the ac or data cables, whilst not causing catastrophic damage, will be slowly stressing the internal microprocessors ultimately leading to degradation which manifests itself as errors or complete failure.
A direct lightning strike can be catastrophic and cause safety related failures and potentially plant shutdowns. The lightning does not have to strike directly even, a nearby strike within a few kilometres can be extremely damaging causing minor failures and potentially stressing control or system hardware.
Surge protection for these industrial process applications can prevent the majority of upsets caused by surges and transients. It is essential as part of the plant infrastructure and can prevent downtime and lost productivity. In all areas reliability will be enhanced increasing availability and uptime. Telematic and Atlantic Scientific have been at the forefront of industrial surge protection for the past 15 years and have the product to protect your facility.
Technical Links From Around The World
4.13 The following links are from IDC Technologies.
Lightning Protection
Protection against Lightning Physical Damage and Life Hazard - SANS 10313:2010 & IEC 62305 Part 2 & 3 Explained - T.J. Manas - This paper covers the process of assessing the risk of damage caused by lightning and give an in depth description of the requirements of protecting structures and living beings against the hazards of lightning - from IDC.
Lightning Protection for Equipment on MV feeders - WJD van Schalkwyk and M. du Preez - This paper presents the influence of lighting on MV feeders supplying small power users (400/230V). Attention is given to insulation failures leading to poor power quality. In order to minimize power interruptions, lightning related trips are reduced mainly by minimizing MV equipment failure. Examples of arc quenching are also studied.
Lightning Protection of Rail and Related Industries - AM (Bert) Hanekom - The rail environment is challenging and merciless. The overhead traction structure literally forms a huge lightning antenna. This requires a systems thinking approach to protect elements that are rail bound, rail mounted or in close proximity to the track, against lightning surges. What makes things even more challenging is the rapid growth in the use of low powered electronic devices in the rail environment. For example, signaling installations have evolved from mechanical interlockings to being based on sophisticated electronic sub elements. Additionally, condition monitoring of the rail infrastructure has brought in numerous electronic systems. Hence the critical need for lightning protection in all aspects of the rail network. The author’s real experience in lighting protection of rail systems is shared with you.
Lightning Protection for Industrial Plants - Phillip Tompson - This paper provides an outline of a systematic approach to determine and apply lightning and surge protection to industrial plants such as water and sewerage and oil and gas facilities. All too often when lightning strikes an industrial plant, equipment is damaged and operations curtailed there is an initial rush to get the plant operational again. This is a reasonable response. Then comes the question of how to protect the plant against the next lightning strike. Inevitably the approach taken is ad hoc and the result is very often a lightning protection system that does nothing to protect the equipment that was originally damaged. Indeed by taking a systematic approach, applying the Australian standard, carrying out a risk assessment, then acting upon the results of that risk assessment both cost effective and successful solutions can be found.
Surge Protection
The Need to Ensure Energy Co-ordination of Surge Arresters in terms of SANS 10142:2009 section L.1.3.3 - Paul van As - This is a topic which is regularly overlooked and probably the most common cause for failure of surge arresters. Many people believe that the more surge arresters you install the better the level of protection obtained. This is all very well if viewed purely from a voltage protection perspective but can lead to premature failure of surge arresters. Cascading of surge arresters based purely on voltage protection levels without fully understanding energy co-ordination is a recipe for disaster. Many suppliers of surge arresters tend to sell their products purely on surge handling ability (kA), reaction time and clamping voltage. Obviously the surge arrester that reacts the fastest is the first to operate and hence takes most of the energy. In many cases this can lead to low energy, fast reacting surge arresters being overstressed causing damage to equipment. In light of the above problem SANS 10142-1:2009 section L.1.3.3, which states “When more than one SPD is connected on the same conductor, coordination between them shall be ensured.” Many manufacturers and sellers of surge arresters have no idea as to how their surge arresters will react when cascaded with each other. This problem is further aggravated when different surge arresters from different manufactures are installed in an installation.
Accurae Soil Resistivity Testing for Power System Earthing - Rodney Urban, Karl Mardira - Soil resistivity data is of fundamental importance in performing earthing system analysis. Reliable data is required to achieve good correlation between design and measured earthing system performance. The findings of numerous soil resistivity tests in the Sydney area for rail system earthing design is presented in this paper. The installations were inside the rail corridor where testing was often very restricted or not possible due to hazards, space limitations and adjacent buried metallic services or structures. A comparison of the results indicates the possible variation of soil resistivity at various depths over small distances and how this can be accommodated in the design process.
Arrester Earthing Resistance - Tony Gillespie - An analysis of the earthing resistance for surge arresters on the distribution network. The simplified analysis is based on lumped parameter circuit impedance values for a lightning strike.
Power System Earthing Due Diligence - Gaye E Francis and Richard M Robinson - There have been two primary paradigms of safety risk management co-existing uneasily over the last few decades. One is related to hazard based risk analysis driven by technical professionals using target levels of risk and/or safety. The other is the precaution based risk analysis driven by the courts focusing on ‘due diligence’ being a demonstration that all reasonable practical precautions are in place based on the balance of the significance of the risk vs the effort required to reduce it. The publication of the EG-0, Power System Earthing Guide, Part 1: Management Principles by Energy Networks Australia in May 2010 supports the hazard based / risk target approach to risk management whilst the impending (2011) national Model Workplace Health and Safety Act requires a positive duty of care for responsible officers to exercise ‘due diligence’. This paper will investigate the underlying conflict between the two positions and the manner of expected resolution using EG-0 as the focus.
Effective Surge Protection Installation - Phillip Tompson - Managing Director, Novaris Pty Ltd - This paper provides an outline of how to effectively install surge protection to various elements of an industrial plant. The paper highlights the need to consider cable impedance and the importance of equipotential bonding.
Comparison of Different Class I Surge Protective Devices for the Protection of Mobile Phone Stations - Holger Heckler, John Ortika - Phoenix Contact (Germany & Australia) - IEC Class I surge protective devices (SPDs) - for the diversion of direct light-ning currents - are frequently used for the protection of low-voltage AC power systems. Nowadays more and more telecommunication applications are also powered with DC power systems (An example being radio base stations, which are equipped with Remote Radio Heads or Remote Radio Units {RRH/RRU}). Remote radio heads are usually powered with 48 V DC. For the efficient protection against the effects of direct lightning strikes, remote radio heads have to be protected with surge protective devices which are suitable for the installation in DC power systems. The IEC standards which describe the requirements and the test conditions for surge protective devices (IEC 61643-1, IEC 61643-11) do not address SPDs connected to DC power systems. In this paper special requirements for SPDs, connected to 48 V DC power systems, are defined and described. Tests carried out with different high performance Class I lightning current arresters, connected to a newly designed test circuit, show the advantages and restrictions of the use of these arresters in DC power systems. The tests had been carried out with different kind of spark gaps, varistors and combinations of spark gaps and varistors.
Practical Insulation Co-ordination for Lightning Induced Overvoltages - Jason Mayer - Technical Director, Energy Services, Aurecon - This paper provides guidance on how to undertake insulation co-ordination simulations in high voltage systems, using time domain software. There are a number of methods used in industry to complete this task. Some are simplified approximations, others involve statistical analysis. This is just one method, but it is a practical means of assessing the level of protection afforded by surge arresters in high voltage systems, against lightning strokes to exposed conductors. The paper does not consider overvoltages from switching transients or other sources, although some of the principles presented could be used in this area.
How Real Time Lightning Data Improves Safety & Reduces Downtime - Ken Ticehurst - Managing Director, Kattron Lightning & Weather Data - A lightning wide area detection network, part of Earth Networks global Total Lightning Network (KENTLN), provides a significant detection advance which enables the severity of a storm to be determined by the rate of Inter-Cloud flashes, 21st century technology provides advanced storm severity before damaging ground strokes begin. Advanced warning can provide alerts 30 to 45 minutes ahead of older technology
Lightning and Underground Mines - An Introduction - Franco D’Alessandro - Principal Consultant, PhysElec Solutions Pty Ltd - Effective mitigation of direct and indirect lightning discharges is an important aspect of the reliable operation of any mining operation. Whilst a systematic protection plan can be implemented relatively easily for above-ground operations, the circumstances are rather more complex for underground mines. The counterintuitive nature of assessing the risk lightning poses to underground mining operations will be developed in this paper. It commences with an overview of the key characteristics of lightning and then outlines the main variables and transfer mechanisms of relevance to underground mines. The paper then provides some examples of calculations carried out to quantify the dangers lightning poses underground.
Other Links
Remote Location Power Surge Protection - David Torres - Remote sites include locations such as telecommunications shelters, cellular towers, water/wastewater treatment plants, railroad bungalows, and HVAC systems. These installations can be challenging to protect from lightning, line surges originating from utility switching, damage to power utility lines, and power surges originating from area industrial equipment. Devices in remote locations are typically closer to the service entrance and lack other power paths for energy to flow. This makes them more susceptible to surge damage than other applications. When planning a remote installation, the design engineer or installer must consider proper grounding and bonding, the correct surge protection device (SPD) for the job, and proper installation. When installed correctly, it is possible to protect a remote site from lightning or other surge events - from ISA and InTech.
Lightning Protection System - Ultimate Line of Defense - Mark S. Harger - Lightning, one of nature’s most destructive forces, continues to wreak havoc on lives and property especially in today’s electronic environment. On average, a lightning strike contains approximately 50 million volts carrying 18,000-20,000 amperes of current, but strikes with up to 300 million volts and 200,000 amps are not that uncommon. To protect against this destructive phenomena, a properly designed and UL-listed lightning protection system is required. The National Fire Protection Association (NFPA) 780 Standard for the Installation of Lightning Protection Systems defines a lightning protection system as “a complete system of strike termination devices, conductors, grounding electrodes, interconnecting conductors, surge suppression devices and other connectors or fittings [that] are required to complete the system.” How does this system work? Picture a hockey goalie protecting his net. He has four basic tools—gloves, mask, stick, and pads—that help him prevent the puck from entering the net. Just like a goalie, there are four main parts that comprise a lightning protection system - from Nema.
Proper Copper Grounding Systems Stops Lightning Damage at Nebraska FM Station - What could be more vulnerable to lightning than a 500-ft antenna tower poking into the Nebraska sky on a summer afternoon? And what could be more at risk from serious lightning damage than the sensitive electronic equipment in a radio station’s transmitter room? One station knows these hazards all too well. KROA, a 100-kW FM station with studios and tower in Doniphan, Nebraska, learned first-hand what happens when lightning strikes and where the lightning goes if the tower it strikes is connected to high-resistance ground. From Copper.org.
Preventing Direct Lightening Strikes - Roy B. Carpenter, Jr - This paper looks at lightening strikes and how to prevent them - from lecglobal.com.
Lightning and Static Effects on Industrial Electronics - This data sheet from Emerson Process Management examines the damage caused by transients from lightning and static and offers advice on minimising the harmful effects of these two phenomena.
Designing for Surge Immunity In International Markets (Applied Energy Concepts - www.aeconcepts.com).
Surge Protection for Modern Process Control and Automation Technology - (Dehn USA - www.dehn-usa.com/).
Lightning Protection for Dam Instrumentation - A paper by Anthony Moulds and Anthony Watson, thanks to http://www.slopeindicator.com/.
Application of Surge Protection Devices for Very Low Voltage Devices - Mike Green - thanks to Megavolt (http://www.megavolt.co.il/) - This paper offers a three point method for simplifying the Surge Protection Device (SPD) selection process, while pointing out the necessity for studying the application in its entirety.
Surge Protection of End-User Equipment - François D. Martzloff - National Institute of Standards and Technology - Technically valid and cost-effective surge protection of end-user equipment can only be achieved by matching the surge withstand capability of equipment (with or without added protection) to the surge environment, the latter being generally beyond the control of the end-user. Thus, three sets of questions must be answered by a facility engineer to arrive at a reliable approach, this paper discusses these.
Surges Happen - How to protect the appliances in your home - A 24 page document from the National Institute of Standards and Technology
NFPA-780 Standard for the Installation of Lightning Protection Systems (1997): Transitioning From An Outdated Concept to Approved Alternatives - By Richard Kithil, President & CEO, NLSI.
Proper Copper Grounding Systems Stops Lightning Damage at Nebraska FM Station
Safety, Power Quality, Communications Improve with Low-Resistance Copper Grounding System - thanks to the Copper Development.
What You Should Know About Lightning Protection - By Joseph H. Reisert - from Astron Wireless Technologies.
Lightning Protection - New Myths & Old Realities As They Apply To Your Home And Your Station - by Bob McGraw - K4TAX.
Lightning Protection of weighing systems - From revere transducers- Europe (www.revere.nl).
Coordination of Telecommunications Surge Protective Devices in Countries with Unstable AC Power - Peter Nystrom-Applied Energy Concepts, Inc. (www.aeconcepts.com).
Lightning Links - from the university of Florida Vladimir A. Rakov, Ph.D. Professor) (http://plaza.ufl.edu/rakov/).
Public Interest Energy Reseach OTC Report on Light Activated Surge Protection Thyristor (LASPT) - 74 pages here - ADSL recommended - From the California Energy Commission - www.energy.ca.gov - The electricity system in California is vulnerable to large-scale power disruptions due to rapid power surges resulting from lightning or mechanical failures. These rapid surges cannot be fully mitigated by the existing surge protection devices in power plants and the transmission and distribution systems. The economical cost of these power failures amounts to more than $1 billion dollars a year. The overall goal of this project was to develop a surge protection device with a response with an order of magnitude faster that systems currently used by the electric power industry. Many current surge protectors employ a switch known as a thyristor that is activated by electrical current. Our goal was to develop a prototype of a Light Activated Surge Protection Thyristor (LASPT) that would respond much faster than current activated thyristors.
Lightning Protection for Wind Turbines - The Lightning Protection Project was conceived by the National Renewable Energy Laboratory (NREL) to improve the understanding of lightning caused damage to wind turbines and how to protect them. This project report is very comprehensive thanks to www.solacity.com.
A New Lightning Protection System for Wind Turbines Using Two Ring-Shaped Electrodes - Yasuda Yoh - This technical paper focuses on a method for protection of low-voltage and control circuits in a wind tower, detailing a new lightning protection system with two ring-shaped electrodes attached to the wind turbine.
Lightning Protection in Rocket Design - Bruce C. Gabrielson Aerojet Electrosystems Azusa, California
The following Surge and lightning protection Application notes are from MTL Instruments
Lightning Surge Protection for Electronic Equipment - A Practical Guide - This publication discusses the nature of the threat to electronic instrumentation and communications networks posed by voltage surges induced by lightning or other causes, and describes the practical application of surge protection devices (SPDs) designed to prevent damage from such sources.
Lightning and Surge protection - Basic Principles - This publication discusses the mechanism of lightning and the design of surge protection devices (SPDs). The criteria for choosing the most suitable models for a wide range of applications in process industries are established. SPD applications for computers, networks, telecomms and various building systems are discussed.
Earthing Guide for Surge Protection - This publication discusses the major aspects of earthing surge protection devices (SPDs), and the relationship between SPD earths and the earthing of the associated instrumentation or other equipment with which the devices are used are also considered.
Surge Protection for Intrinsically Safe Systems - This publication discusses the nature of the threat to intrinsically safe instrumentation in hazardous areas from voltage surges induced by lightning or other causes. The practical application of surge protection devices (SPDs) taking into account the approvals requiredis also considered.
Surge Protection for Zone 0 Locations - This note discusses the surge protection requirements of intrinsically safe circuits entering a Zone 0 hazardous area. It analyses the potential gradients generated by lightning strikes and their possible routes of invasion. The alleviation of the problem at the zone 0 interface transfers the problem elsewhere and an adequately safe pragmatic solution is proposed.
Surge Protection for Weighing Systems - An Application Guide - This publication discusses the nature of modern weighing systems and describes the various methods by which surge protection can be applied to load cells (digital and conventional), to control systems, etc., within the weigh cabin and to external system links.
Surge Protection for Local Area Networks - This publication discusses ways in which Local Area Networks can be damaged by lightning-induced transients, and how they can be protected economically.
Surge protection for electrical power installations - This publication discusses the affects of surges and lightning induced overvoltages on ac power systems. The note will introduce the source of many common transients and surges and suggest the application of surge protection devices in this area. Finally, typical examples are shown for common installations.
Lightning & surge protection for fieldbus systems - This publication contains a brief introduction to fieldbus systems. It continues by describing the surge protection necessary to protect such systems from the detrimental effects of lightning and other surges.
System Reliability and Surges - This article from Intech and Chris Towle of MTL discusses the risk that lightning-induced surges pose on a process plant.
Reliability, Availability, Maintenance, Return on Assets and Surge Protection - In this article Anthony O Bird discusses the appropriate level of surge protection that when applied to a process plant, reduces equipment fialure directly, increases plant availability and indirectly frees the maintenance team up to perform a more proactive role.
Surge Protection for Offshore Platforms - This paper discusses the vulnerability of various electrical and electronic systems against the impact of a lightning storm on an offshore platform.
Washington Gas - True Story - This paper points out the benefits to Washington Gas from their invested in surge protection to safeguard their equipment and reduce associated maintenance expenses.
Reliability of Surge Protection devices used with fieldbus systems - MTL instruments.
Surge Protection for Fieldbus without Performance Limitations
This article discusses a complete surge protection solution for an entire Foundation Fieldbus system without performance limitations.
Lightning and surge protection in emissions monitoring - Donald Long - At any given moment, there are over 1,800 thunderstorms occurring - The 1,000-ft stacks at electrical power generating plants are huge lightning rods reaching up into the sky. The very same stacks, selective catalytic reaction (SCR) beds, ammonia injectors, and precipitators, only now carrying expensive nitrogen oxide/sulfur dioxide (NOx/SO2) emissions monitoring equipment and associated power and instrumentation cabling, take on nature's fury in the form of potentially 200,000-ampere bolts of lightning. How can one effectively deal with this phenomenon? How does lightning get into the continuous emissions monitoring system (CEMS)? Is this the only form of surge? Is proper grounding the answer? Thanks to ISA and InTech.