Non-Conventional Lightning Protection System – Part Three


In Article Types Of Lightning Protection Systems LPS ", I list the main types of Lightning Protection Systems as follows:




Types of Lightning Protection Systems LPS

Lightning protection systems for buildings and installations may be divided into three principal types as follows:

1- LPS for Protection for buildings and installations against direct strike by lightning, which includes:

A- Conventional lightning protection system, which includes:

  1. Franklin Rod LPS,
  2. Franklin/Faraday Cage LPS.


B- Non-Conventional lightning protection system, which includes:

a- Active Attraction LPS, which includes:

  1. Improved single mast system (Blunt Ended Rods),
  2. Early streamer Emission System.


b- Active Prevention/Elimination LPS, which includes:

  1. Charge Transfer System (CTS),
  2. Dissipation Array System (DAS).


2- LPS for Protection against overvoltage on incoming conductors and conductor systems,

3- LPS for Protection against the electromagnetic pulse of the lightning.






And, I explained the Conventional Lightning Protection System parts and components in the following Articles:




And in Article " Non-Conventional Lightning Protection System – Part One ", I explained the first type of Non-Conventional Lightning Protection System which is Active Attraction LPS, which includes:
  • Improved single mast system (Blunt Ended Rods),
  • Early streamer Emission System.



Also, in Article " Non-Conventional Lightning Protection System – Part Two ", I explained the following points:

  • Differences in Lightning Protection Technologies,
  • Principle of Operation for Active Prevention/Elimination LPS,
  • Types Of Lightning Elimination/Prevention Systems.


Today, I will explain in details the Dissipation Array System (DAS).


For more information, you can review the following Articles:





Non-Conventional Lightning Protection System






1- Components of Non-Conventional Lightning Protection System

Non-Conventional lightning protection system includes (2) main types as follows:

a- Active Attraction LPS, which includes:

  • Improved single mast system (Blunt Ended Rods),
  • Early streamer Emission System.


b- Active Prevention/Elimination LPS, which includes:

  • Charge Transfer System (CTS),
  • Dissipation Array System (DAS).








2- General Information About
Non-Conventional Lightning Protection System

  • In the 1970s, two types of unconventional air terminals had been commercially reinvented and introduced in the world market under a variety of trade names. They are:


1- The lightning Active Attraction air terminal: 

the lightning attracting air terminal is claimed to be able to attract the lightning to it (and hence away from the building) in order to protect the building that it was installed on.

 2- The lightning Active Prevention/Elimination air terminal:

 the lightning prevention air terminal is claimed to be able to prevent lightning from occurring and hence protect the building.

  • Some of the trade names for of unconventional air terminals are as follows:



Product Name
Country
Dynasphere
Australia
Prevectron
France
EF
Swiss
St. Elmo
France And Italy
Pulsar
France
DAT Controler
Spain
Paratonerre
France
Preventor
France And UK
EF33
Australia


  • In reality, the inventors of these un-conventional air terminals have never been able to provide any scientific basis for their invention. None of the “scientific papers” that they have published in the last 30 years have been independently verified by the scientific community.
  • In addition to this, these inventors have never been able to provide any independently validated proof that their inventions work. However, they have provided plenty of anecdotal (i.e. hearsay) evidence which had been obtained from “satisfied customers” and some insurance carriers will accept them as equivalent for the conventional techniques.
  • These Non-conventional air terminals are claimed to be superior to the conventional lightning protection but neither experimental data nor theory supports these claims.

  • For these reasons, these inventors and manufacturers have not been able to get their unconventional air terminals approved by the standards bodies like:

  1. NFPA,
  2. IEEE,
  3. IEC,
  4. US Military,
  5. UL.


  • Hence the LPS that used these Non-conventional air terminals have been classified as Non-standard LPS by academics, scientists and the various standards bodies around the world.
  • The Non-standard LPS are usually easier and cheaper to install when compared to the conventional system but the protection that it provides is very limited i.e. equivalent to that of a single Franklin rod! Hence these vendors had to rely on some very creative marketing to sell their non-scientific and unproven products.








Important Note

The volume or zone of protection afforded by the air termination system shall be determined only by the real physical dimension of the air termination system. Typically if the air rod is 5m tall then the only claim for the zone of protection afforded by this air rod would be based on 5m and the relevant Class of LPS and not any enhanced dimension claimed by some non-conventional air rods.







Second: Active Prevention/Elimination LPS






Important Note

In this Article, I will discuss the Active Prevention/Elimination LPS from the point of view of their proponents and in next articles; I will discuss the arguments against the claimed advantages of Active Prevention/Elimination LPS by their proponents.






1- The Active Prevention/Elimination LPS Components


Dissipation Array System Mounted on A Communication Tower


The Dissipation Array is a key component of Active Prevention/Elimination LPS, working with grounding and surge suppression to achieve complete protection. A typical Active Prevention/Elimination LPS includes (see Fig.1):

  1. The Dissipation Array (Dissipation Ionizer or The Charge Transfer Mechanism),
  2. Spline Ball Diverter System (SBDS),
  3. The Ground Charge Collector (GCC),
  4. The Charge Conductor (CC),
  5. Transient Voltage Surge Suppression (TVSS),
  6. Special Lightning Elimination Air Terminals.



Fig.1: Dissipation Array System Components


Note:

Some or all of these components may be used in designing a particular DAS protection system.






1.1 The Dissipation Array (Dissipation Ionizer or the Charge Transfer Mechanism) 
(see Fig.1)

  • Dissipation Ionizer is the charge transfer component, and the most design sensitive. A Dissipation Ionizer comes with many hundreds of points i.e. Dissipation Ionizer is a multi-point device.
  • Its function is to transfer the collected charge to the adjacent air molecules via a principle known as “point discharge.” The resulting ions make up what is known as “space charge”, a mixture of charged and uncharged particles. This space charge forms a shield between the protected site and the storm cell. The result of this shielding effect is a reduction of the electrostatic field within the sphere of influence of that space charge.
  • The Ionizer may be designed to create the required space charge density independent of that to be protected.
  • The ionizer assembly is very sensitive to a number of design parameters, some of which can be reduced to formulation, others which cannot. These factors include size, shape, elevation, point shape, point height above the array face, point spacing, range in wind velocity, plus the character and relationship of the surroundings. Thus, effective system design remains as much an art as a science.




Different Configurations of Dissipation Ionizer



Fig.2: Different Configurations of Dissipation Ionizer


The ionizer is available in a range of configurations for almost any structure as follows (see Fig.2):


1- Hemisphere Array

It Can be placed on any industrial or commercial structure, including poles, buildings, and towers.


2- Parapet Array

It is used for any commercial or industrial flat roof building with parapet around the edge.


3- Flat Roof Array

It is used for any flat-roof building. It May be used to supplement protection on a roof that has a parapet array.


4- Conic Array

It is used for cone roof and dome roof storage tanks. Commonly used in petrochemical and flammable storage industry.


5- Rim Array

Designed for floating roof tanks used in petrochemical and flammable storage industry.


6- Stack Array

Used on industrial smoke/exhaust stacks. Corrosion resistant designs available.


7- Trapezoid Array

For use on industrial and commercial structures with guy ropes, Effective even if not the highest point.


8- Paragon Array

Multiple use configuration. Variant commonly used on transmission and distribution lines.







1.2 Spline Ball Diverter System (SBDS)

  • Spline Ball Diverter System (SBDS) called as hybrid ionizers, which combine the features of the ionizer with those of the air terminal. Its main function to supplement the Dissipation Array’s area of protection as needed.
  • Spline Ball assemblies are UL listed under UL96A as “air terminals”, and qualify as ionizer modules and therefore are usable as such in any NFPA780 based system. The multiple points make them an ionizer. The proper spacing of points assures optimum ionization current before it switches to the “collector mode”. 
  • Spline Ball assemblies are made up of about 100 points each, which when deployed, present points set in all 360 degrees in azimuth and about 200 degrees in elevation. As a result, regardless of the orientation of the storm-related electric field or an incoming leader, many ionizer points will be oriented directly toward it and ready to transfer the charge rapidly.
  • These forms of ionizer modules support a wide variety of applications. When enough of these modules are used to replace conventional air terminals, this converts a conventional collector system to a preventor system.

  • Spline Ball Diverter System (SBDS) includes two products:


  1. The Spline Ball Ionizer (SBI) Module,
  2. The Spline Ball Terminal (SBT) Module.





1- The Spline Ball Ionizer (SBI) Module


Fig.3: Spline Ball Ionizer


  • The Spline Ball Ionizer (see Fig.3is UL listed and used to supplement DAS, and/or for structures that require lightweight protection with a low wind profile. When used as primary protection the SBI acts as a hybrid ionizer/air terminal, preventing most strikes and collecting any it cannot prevent. It provides multiple layers of protection for critical applications.
  • In its primary mode, the SBI lowers the risk of direct strikes by utilizing a phenomenon known as charge transfer, where a well grounded point exchanges ions between the air and earth. This ionizing capability helps keep the local electric field below lightning potential, making the protected site less likely to experience direct strikes.
  • Under intense storm conditions, the SBI functions as a highly effective air terminal, safely collecting any strikes it cannot prevent. In contrast to wire brush devices that are often left ineffective after a single strike, the SBI continues to reduce the risk of subsequent strikes.
  • The SBI’s unique design and geometry also enable it to collect an incoming strike from virtually any direction, creating a larger area of protection than standard air terminals.
  • The SBI is a building block toward complete lightning protection when used for basic risk reduction, or when used with DAS as part of an integrated solution.


The SBI Advantages:

  1. Prevents most lightning strikes,
  2. Minimizes damage potential,
  3. Stainless steel construction,
  4. Easy installation,
  5. UL listed.



2- The Spline Ball Terminal (SBT) Module


Fig.4: Spline Ball Terminal 


  • The Spline Ball Terminal (see Fig.4) replaces standard lightning rods in new or existing NFPA 780 or UL 96A installations. Like the SBI, the SBT reduces the risk of direct strikes in its primary mode and acts as a highly efficient air terminal in secondary mode.
  • The Spline Ball Terminal from Lightning Eliminators offers a superior alternative to standard air terminals for new or existing lightning protection systems. Unlike traditional lightning rods designed only to collect, the SBT is engineered to both reduce the risk of direct strikes and function as a highly efficient air terminal.
  • In its primary mode, the SBT lowers the risk of direct strikes through a phenomenon known as charge transfer, where a well-grounded point exchanges ions between the air and earth. This ionizing capability helps keep the local electric field below lightning potential, making the protected site less likely to experience direct strikes.
  • During intense storm activity, the SBT functions as a highly effective air terminal, safely collecting any strikes it cannot prevent. The SBT’s unique design and geometry also enable it to collect an incoming strike from virtually any direction, creating a larger area of protection than standard air terminals that rely on a single point.
  • The UL listed Spline Ball Terminal is an off-the-shelf product that mounts easily in existing hardware, offering a simple and inexpensive way to improve the performance of standards-based systems. For use in any UL 96A, NFPA 780, or Master Label installation.


The SBT Advantages:

  1. Hybrid protection,
  2. Easy installation,
  3. Stainless steel construction,
  4. Light weight, low wind profile,
  5. Minimizes risk to property and personnel,
  6. UL listed replacement for standard air terminals.








1.3 The Ground Charge Collector (GCC)


  • The ground charge collector (GCC) (see Fig.1) is analogous to the conventional grounding system except the GCC is a collector and not an earthing system for strikes.The Ground Current Collector (GCC) provides the source of charge to keep the ion current flowing through the array and discharge the site.
  • The GCC is designed to provide an electrically isolated or floating ground subsystem for the protected area with respect to the earth. Since the induced charge created by the storm is at the earth’s surface, that portion of the earth’s surface containing the facilities to be protected is usually surrounded with the GCC. As a special example, if a building is to be protected, building steel provides the best GCC function for that building.

  • The GCC is normally composed of:

  1. The Ground Current Collector wire or copper tubing buried to a depth of about 25 centimeters,
  2. Short ground rods along the GCC at intervals of about ten meters,
  3. A net of cross conductors along the enclosed area used for connecting surface structures and the grounding system.


  • As the charge moves into the area, it first interfaces with the GCC which provides a preferred path for the charge from this point of interface to the dissipater or ionizer assembly by means of the service wires, thus essentially bypassing the protected area.
  • The current flow thus created through the surrounding surface soil causes a small voltage drop across that soil resistance. Thus, the electrically integrated, isolated island established by the GCC is reduced to a lower potential than its surroundings.
  • The short ground rods give the island enough depth to ensure collection of any charge induced within the area of concern.

  • The significance of the electrically isolated island and ionic current flow can be summarized as follows:
  1. The current flow from the ionizer through the air space above it reduces the potential of the protected site and facility with respect to its surroundings by draining the charge from the protected area and transferring it to the air molecules.
  2. The presence of free ions or space charge between the protected facility and the cloud structure forms a type of Faraday shield between them, thus providing isolation for the facility from the storm cloud’s static field.


  • For ensuring a low-impedance grounding system, chemically-charged electrodes (Chem-Rod™) (see Fig.5) can be used. Chem-Rod Grounding Electrode is an ultra-efficient low surge impedance grounding system. It provides the perfect low resistance interface with true earth by continuously conditioning the surrounding soil, using specially formulated mineral salts evenly distributed along the entire length of the electrode. It is so efficient that one Chem-Rod can replace up to ten conventional grounding rods. The design of the Chem-Rod insures a stable, efficient system that is virtually maintenance free.

Fig.5: chemically-charged electrodes (Chem-Rod™)








1.4 The Charge Conductor (CC) (Labeled “Service Wires”)


  • The Charge Conductors (CC) are connecting the ionizer to the grounding system (see Fig.1). They are analogous to the conventional down conductor; but should be thought of as an “up conductor” because its function is to conduct the collected charge to the ionizer, providing a direct, low surge impedance path from the GCC to the ionizer.
  •  In contrast to a lightning rod system, these wires carry low current levels over the shortest path possible and are selected more for structural integrity than for current carrying capacity. For example, Building steel and towers are ideal charge transfer conductors.
  • The maximum current flow is in the milli-ampere range. Measurements indicate less than ½ ampere at maximum flows through a GCC grounding system (except on rare occasions).







1.5 Transient Voltage Surge Suppression (TVSS)

  • The voltage line anomalies are the greatest source of destructive and disruptive phenomena that electrical and electronic equipment experience in day-to-day operations. 
  • These anomalies can be prevented or mitigated in electrical substations, along power lines, at the entrance to an individual facility, or on internal data lines, this is done by using surge suppression devices to protect against transients traveling through data lines and other conductive paths.







1.6 Special Lightning Elimination Air Terminals


Besides the DAS, other lightning prevention air terminals have also been brought into the country in recent years due. They are very much smaller in size and in various shapes. Example for these Special lightning elimination air terminals is Ion Plasma Generator (IPG).



Ion Plasma Generator (IPG)


Fig.6: Ion Plasma Generator


  • For specialized applications like wind turbines and T&D systems, the Ion Plasma Generator is the most effective air terminal available (see Fig.6). 
  • The IPG is used to create a preferred collection point in cases where strike prevention is less feasible.The patented Ion Plasma Generator is a highly effective air terminal engineered for applications where lightning prevention is not practical, but that still require reliable protection from direct strikes.
  • During lightning conditions, the IPG acts as the most attractive object in the protected area by using the storm’s energy to develop a dense corona plasma. As the electrical field grows, this highly charged corona becomes more attractive, drawing strikes safely to the IPG and preventing damage to valuable assets.
  • Unlike traditional collectors that often fail to exert enough attractive influence on approaching strikes, the IPG’s materials and construction are optimized for maximum risk reduction in a cost effective and durable design.


Ion Plasma Generator (IPG) Applications:

  1. Wind Turbines,
  2. T&D Systems,
  3. Mining Operations,
  4. Parking Structures.





In the next Article, I will explain the Design considerations for Dissipation Array System (DAS). Please, keep following.




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