Design Process For Lightning Protection Systems


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

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



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




 Today, I will explain The Design Process For Lightning Protection Systems.







Design Process For Lightning Protection Systems





Design Process For Lightning Protection Systems

The design process of lightning protection systems is commonly broken into discrete phases, allowing the lightning protection designer to present an integrated design package. These phases can be listed as follows:

  1. Planning phase,
  2. Consultation phase,
  3. Detailed Design phase.


A Quality assurance is required in each phase in above.





First: Planning phase




In the planning phase, the following steps should be followed:

1- Check the structure’s Need for lightning protection

  • Where the LPS has not already been specified by the licensing authority, insurer or purchaser, the lightning protection designer should determine whether or not to protect the structure with an LPS by following the procedures for risk assessment given in IEC 62305-2.
  • The decision to provide lightning protection may be taken regardless of the outcome of risk assessment where there is a desire that there be no avoidable risk. Lightning protection can be installed even when the risk management process may indicate that it is not required. A greater level of protection than that required may also be selected.
  • Local regulations requirements, if any, may be applicable and have to be taken into account.


2- Get Input data from Owner or Owner’s Representatives

Before any detailed design work on the LPS is commenced, the lightning protection designer should, where reasonably practical, obtain basic information regarding the function, general design, construction and location of the structure.


3- Coordinate with Public utilities

Bonding of incoming services to the LPS directly or, if this is not possible, through isolating spark gaps or SPD should be discussed with the operator or authorities concerned, as there may be conflicting requirements.

4- Coordinate with Fire and safety authorities

Agreement should be reached with the fire and safety authorities on the following items:

  • The positioning of alarm and fire extinguishing system components;
  • Routes, construction material and sealing of ducts;
  • The method of protection to be used in the case of a structure with a flammable roof.





Second: Consultation phase




  • The lightning protection designer should hold relevant technical consultations with all parties involved in the design and construction of the structure, including the owner of the structure.
  • Particular areas of responsibility for the total installation of the LPS should be defined by the LPS designer in conjunction with the architect, electrical contractor, building contractor, the LPS installer (LPS supplier) and, where relevant, a historical adviser and the owner or owner’s representative.
  • Regular consultation between LPS designers and installers, architects and builders is essential in order to achieve the best result at minimum cost.
  • The clarification of responsibility for the various parties involved in the management of the design and construction of the LPS is of particular importance. An example might be where the waterproofing of the structure is punctured by roof-mounted LPS components or by earth electrode connection conductors made below the structure foundation.


1- Technical consultations with Architect




Agreement should be reached with the architect on the following items:

  • Routing of all LPS conductors;
  • Materials for LPS components;
  • Details of all metal pipes, gutters, rails and similar items;
  • Details of any equipment, apparatus, plant installations, etc. to be installed on, within or near the structure which may require the moving of installations or may require bonding to the LPS because of the separation distance. Examples of installations are alarm systems, security systems, internal telecommunication systems, signal and data processing systems, radio and TV circuits;
  • the extent of any buried conductive service which could affect the positioning of the earth termination network and be required to be placed at a safe distance from the LPS;
  • The general area available for the earth-termination network;
  • The extent of the work and the division of responsibility for primary fixings of the LPS to the structure. For example, those affecting the water tightness of the fabric (chiefly roofing), etc;
  • conductive materials to be used in the structure, especially any continuous metal which may have to be bonded to the LPS, for example stanchions, reinforcing steel and metal services either entering, leaving, or within the structure;
  • The visual impact of the LPS;
  • The impact of the LPS on the fabric of the structure;
  • The location of the connection points to the reinforcing steel, especially where they penetrate external conductive parts (pipes, cable shields, etc.);
  • The connection the LPS to the LPS of adjacent buildings.



2- Technical consultations with Electronic system and external antenna installers

Agreement with the electronic system and antenna installer should be reached on the following items:

  • The isolating or bonding of aerial supports and conductive shields of cables to the LPS;
  • The routing of aerial cables and internal network;
  • Installation of surge protective devices.







3- Technical consultations with Builder and installer

Agreement on the following items should be reached between the builder, installer, and those responsible for construction of the structure and its technical equipment:

  • The form, position and number of primary fixings of the LPS to be provided by the builder;
  • Any fixings provided by the LPS designer (or the LPS contractor or the LPS supplier) to be installed by the builder;
  • The position of LPS conductors to be placed beneath the structure;
  • whether any components of the LPS are to be used during the construction phase, for example the permanent earth-termination network could be used for earthing cranes, hoists and other metallic items during construction work on the site;
  • For steel-framed structures, the number and position of stanchions and the form of fixing to be made for the connection of earth-terminations and other components of the LPS;

  • Whether metal coverings, where used, are suitable as components of the LPS;
  • The method of ensuring the electrical continuity of the individual parts of the coverings and their method of connecting them to the rest of the LPS where metal coverings are suitable as components of the LPS;
  • the nature and location of services entering the structure above and below ground including conveyor systems, television and radio aerials and their metal supports, metal flues and window cleaning gear;
  • Coordination of the structure's LPS earth-termination system with the bonding of power and communication services;
  • the position and number of flag masts, roof-level plant rooms, for example lift motor rooms, ventilation, heating and air-conditioning plant rooms, water tanks and other salient features;
  • the construction to be employed for roofs and walls in order to determine appropriate methods of fixing LPS conductors, specifically with a view to maintaining the water tightness of the structure;
  • The provision of holes through the structure to allow free passage of LPS down conductors;
  • The provision of bonding connections to steel frames, reinforcement bars and other conductive parts of the structure;
  • The frequency of inspection of LPS components which will become inaccessible, for example steel reinforcing bars encapsulated in concrete;
  • The most suitable choice of metal for the conductors taking account of corrosion, especially at the point of contact between dissimilar metals;
  • Accessibility of test joints, provision of protection by non-metallic casings against mechanical damage or pilferage, lowering of flag masts or other movable objects, facilities for periodic inspection especially for chimneys;
  • The preparation of drawings incorporating the above details and showing the positions of all conductors and main components;
  • The location of the connection points to the reinforcing steel.



4- Technical consultations with Electrical designer

Agreement on the following items should be reached between the builder, installer, and those responsible for construction of the structure and its technical equipment:


  • The proper use of foundation steelwork for the purpose of forming an effective earth-termination may well be impossible once construction work on a site has commenced. Therefore, soil resistivity and the nature of the earth should be considered at the earliest possible stage of a project. This information is fundamental to the design of an earth termination system and may influence the foundation design work for the structure. Soil resistivity tests should take into consideration the seasonal variations of soil resistivity.
  • During the completion of the basic electrical design of the LPS, the use of suitable conductive parts of the structure should be considered as natural components of the LPS to enhance or act as essential components of the LPS.
  • The use of metal reinforcing, such as steel-reinforced concrete, as lightning protection conductors requires careful consideration, and knowledge of the national construction standards applicable to the structure to be protected. The steel skeleton of reinforced concrete may be used as LPS conductors or may be used as a conductive shielding layer to reduce the electromagnetic fields generated by lightning in the structure as the lightning currents are conducted through an isolated LPS. This LPS design makes protection easier, in particular for special structures containing extensive electrical and electronic installations.



5- Technical consultations with Mechanical designer

The lightning protection designer should consult with the persons responsible for the structure on mechanical design matters, following the completion of the electrical design, for the following points:

  • The minimum size of lightning protection components for the various parts of the LPS.
  • The materials used for the LPS components.
  • The lightning protection designer or installer should predict the temperature rise and mechanical strength of lightning conductors and other components, such as rods and clamps under discharge conditions and dimension the conductors accordingly.
  • When excessive temperature rise is a concern for the surface on which the components are to be attached (because it is flammable or has a low melting point), either larger conductor cross-sections should be specified or other safety precautions should be considered, such as the use of stand-off fittings or the insertion of fire-resistant layers.
  • The LPS designer should identify all corrosion problem areas and specify appropriate measures.
  • The corrosion effects on the LPS may be reduced either by increases in material size, by using corrosion resistive components, or by taking other corrosion protection measures.
  • The LPS designer and LPS installer should specify conductor fasteners and fixtures which will withstand the electrodynamic forces of lightning current in the conductors and also allow for the expansion and contraction of conductors due to the increase in temperature that occurs.


Notes to Consultation Phase:

  • In the design and construction stages of a new structure, the LPS designer, LPS installer and all other persons responsible for installations in the structure or for regulations pertaining to the use of the structure (e.g. purchaser, architect and builder) should be in consultation regularly.
  • In the design and construction stages of an LPS for an existing structure, consultations should be held as far as reasonably practical with the persons responsible for the structure, its use, installations and incoming services.
  • The consultations may have to be arranged through the owner, the building contractor of the structure or their appointed representative.
  • Regular consultations between the involved parties should result in an effective LPS at the lowest possible cost. For example, the coordination of LPS design work with construction work will often do away with the need for some bonding conductors and reduce the length of those which are necessary. Building costs are often reduced substantially by the provision of common routes for various installations within a structure.
  • Consultation is important throughout all stages of the construction of a structure as modifications to the LPS may be required due to changes in the structure design.
  • Consultation is also necessary so that arrangements can be agreed to facilitate inspection of the parts of the LPS which will become inaccessible for visual control after the structure is completed. In these consultations, the location of all connections between natural components and the LPS should be determined. Architects are normally available to arrange and coordinate consultation meetings for new building projects.




Third: Detailed Design Phase

This Phase will be explained in next Articles, however below find our Recommendation for Efficient Lightning Protection System Design





General Recommendation for
Efficient Lightning Protection System Design




  • The LPS designer should select the appropriate LPS to obtain the most efficient construction. This means consideration of the architectural design of the structure to determine whether an isolated or non-isolated LPS, or a combination of both types of lightning protection, should be used.
  • The proper use of foundation steelwork for the purpose of forming an effective earth-termination may well be impossible once construction work on a site has commenced. Therefore, soil resistivity and the nature of the earth should be considered at the earliest possible stage of a project. This information is fundamental to the design of an earth termination system and may influence the foundation design work for the structure. Soil resistivity tests should take into consideration the seasonal variations of soil resistivity.
  • During the completion of the basic electrical design of the LPS, the use of suitable conductive parts of the structure should be considered as natural components of the LPS to enhance or act as essential components of the LPS.
  • It is the responsibility of the LPS designer to evaluate the electrical and physical properties of natural components of the LPS and to ensure that they conform to the minimum requirements of this standard.
  • The use of metal reinforcing, such as steel-reinforced concrete, as lightning protection conductors requires careful consideration, and knowledge of the national construction standards applicable to the structure to be protected. The steel skeleton of reinforced concrete may be used as LPS conductors or may be used as a conductive shielding layer to reduce the electromagnetic fields generated by lightning in the structure as the lightning currents are conducted through an isolated LPS. This LPS design makes protection easier, in particular for special structures containing extensive electrical and electronic installations.
  • A stringent construction specification for down-conductors is required in order to meet the minimum requirements for natural components.
  • The type and location of an LPS should be carefully considered in the initial design of a new structure, thereby enabling maximum advantage to be taken of the electrically conductive parts of the structure. By doing so, design and construction of an integrated installation is made easier, the overall aesthetic aspects can be improved, and the effectiveness of the LPS can be increased at minimum cost and effort.
  • In the design and construction stages of a new structure, the LPS designer, LPS installer and all other persons responsible for installations in the structure or for regulations pertaining to the use of the structure (e.g. purchaser, architect and builder) should be in consultation regularly.
  • In the design and construction stages of an LPS for an existing structure, consultations should be held as far as reasonably practical with the persons responsible for the structure, its use, installations and incoming services.
  • The consultations may have to be arranged through the owner, the building contractor of the structure or their appointed representative.
  • The construction of an LPS for an existing structure should always be weighed against other measures of lightning protection conforming to this standard which give the same protection level for reduced costs. For selection of the most suitable protection measures, IEC 62305-2 applies.
  • The LPS should be designed and installed by LPS designers and installers.
  • The designer and installer of an LPS should be capable of assessing both the electrical and mechanical effects of the lightning discharge and be familiar with the general principles of electromagnetic compatibility (EMC).
  • Furthermore, the lightning protection designer should be capable of assessing corrosion effects and judging when it is necessary to seek expert assistance.
  • The lightning protection designer and installer should be trained in the proper design and installation of the LPS components in accordance with the requirements of standards and the national rules regulating construction work and the building of structures.
  • The functions of an LPS designer and installer may be performed by the same person.
  • A thorough knowledge of the relevant standards and several years of experience is required to become a specialized designer or installer.
  • Planning, implementation and testing of an LPS encompasses a number of technical fields and makes demands for coordination by all parties involved with the structure to ensure the achievement of the selected lightning protection level with minimum cost and lowest possible effort. The management of the LPS should be efficient if the steps in Figure E.1 are followed.
  • A technically and economically optimized design of an LPS is possible, especially if the steps in the design and construction of the LPS are coordinated with the steps in the design and construction of the structure to be protected. In particular, the design of the structure itself should utilize the metal parts of the structure as parts of the LPS.
  • The design of the class and location of the LPS for existing structures shall take into account the constraints of the existing situation.





Fourth: Quality Assurance




Quality assurance measures are of great importance; in particular for structures including extensive electrical and electronic installations, this importance can be summarized as follows:

  • The quality assurance measures extend from the planning stage, in which all drawings should be approved, through the LPS construction stage during which all essential parts of the LPS inaccessible for inspection after the construction works have been finished should be checked.
  • Quality assurance measures continue through the acceptance stage, when final measurements on the LPS should be performed together with the completion of the final test documentation and finally through the entire lifetime of the LPS, by specifying careful periodic inspections in accordance with the maintenance program.
  • Where modifications are made to a structure or its installations, a check should be made to determine whether the existing lightning protection still conforms to this standard. If it is found that the protection is inadequate, improvements should be implemented without delay.



In the next Article, I will explain Design Calculations of Lightning Protection System. Please, keep following.


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