Design Calculations of Lightning Protection Systems – Part Twelve

In Article  " Design Calculations of Lightning Protection Systems – Part Two ", I indicated the lightning protection design process involves a number of design steps as in Fig.1.


Fig.1: The Lightning Protection Design Process



Step#1: Characteristics of the Structure to Be Protected
Explained in above Article




Step#2: Risk Assessment Study



Also, In above Article, I indicated that:




Methods Of Calculations For Risk Assessment Study

The risk assessment study can be done by (4) different methods as follows:

1- Manual Method (equations and tables method),which will be explained as per:
  • IEC 62305-2,
  • NFPA780.

2-Software Method,
3- Excel Sheets Method,
4-Online Calculators Method.




First: Manual Method (Equations And Tables Method) as per IEC 62305-2




The Manual Method (Equations and Tables Method) for Calculations of Risk Assessment Study as per IEC 62305-2 can be reviewed in the following Articles:





First: Manual Method (Equations And Tables Method) as per NFPA 780




The Manual Method (Equations and Tables Method) for Calculations of Risk Assessment Study as per IEC 62305-2 can be reviewed in the following Articles:





Second: Software Method For Performing The Risk Assessment Study




As we see in the previous Articles of the First Method: Manual Method (Equations and Tables Method) that the Manual Method is time-consuming and not always easy to apply the procedures and data given.

Hence, most of the lightning designers use various types of software to perform the Risk Assessment Study. I will explain some of these software programs which are:

S/N
Program
By
1
StrikeRisk V5.0
Furse Company
2
RAPAL
Faculty of Engineering- Aristotle University of Thessaloniki
3
Riesgo
Applicationes Tecnologicas Company

Today, I will explain the first software: Strike Risk V5.0 as follows.



I explained the first software: StrikeRisk V5.0 in Article " Design Calculations of Lightning Protection Systems – Part Ten ". 


And I explained the Second software: RAPAL Software in Article " Design Calculations of Lightning Protection Systems – Part Eleven ".

Today, I will explain the Third software: Riesgo software for performing the Risk Assessment Study: Software Method.



For more information, please review the following Articles:






Riesgo Software




Why using Riesgo Software?

This application is simple to use and highly intuitive, in order to:

  1. Calculate the risk of a building according to main standards like IEC EN 62305.
  2. Compute basic risk assessment for structures or for the services one of them at the same time.
  3. Generate a customized report containing a normative justification.
  4. Request a detailed quotation.



Note:

The software developed does not evaluate the risk values for structures partitioned in zones and neither for services partitioned in sections. Additionally, the evaluation of cost effectiveness of protection is not achieved.




Second: The Construction of Riesgo Software

This software program consists of:

  1. Program Tab,
  2. Program windows.





First: Program Tab



Program Tab

The program Tab includes:

1- Language buttons

After installation of Riesgo, you can configure the Interface Language by selecting between (4) different languages:

  • Spanish,
  • English,
  • French,
  • Portuguese.


2- Right and left big arrows

  • Right arrow: Go to next step.
  • Left arrow: Go back to previous step.


3- Open button: Open saved existing project.

4- New button: Make new project.

5- Save button: Save new/modification to existing project.

6- Delete button: Delete existing/saved project.





Second: Program Windows


Program Windows


This program consists of (10) windows as follows:

  1. Company window,
  2. Project window,
  3. General data window,
  4. Risk calculation window,
  5. Location of the buildings window,
  6. Location of the air terminals window,
  7. External protection window,
  8. Internal protection window,
  9. Report window,
  10. Ask for quotation window.





Notes:

  • Some of these windows are active in the free version of this program and the other windows aren't active. So, if you need to use the inactive windows, you must buy the full paid version from Applicationes Tecnologicas Company.
  • The free version of this program helps in Determination of the need for protection according to UNE – EN 62305-2 and assigns the required level of protection for one building only.





1- Company Window


Company Window


In this window, you will write the data of the designer's company as follows:

  • Serial number: a free serial number is provided automatically.
  • Company: Indicate the name of the designer's company.
  • Contact: Indicate the contact details of the designer's company.
  • Address: Indicate the address of the designer's company.
  • City: Indicate the city of the designer's company.
  • Province/state:  Indicate the Province/state of the designer's company.
  • Email: Indicate the Email of the designer's company.
  • Telephone: Indicate the Telephone of the designer's company.
  • Fax: Indicate the Fax of the designer's company.
  • VAT number: Indicate the VAT (Value Added Tax) number of the designer's company.
  • Country: Indicate the country of the designer's company. You can select the country from the countries box in the right as in below image.

Country Selection






2- Project Window


 Project Window


In this window, you will write the data of the project as follows:

  • Project: Indicate the name of the place to be protected.
  • Address: Indicate the address of the place to be protected.
  • City: Indicate the city of the place to be protected.
  • Province/state: Indicate the Province/state of the place to be protected.
  • Country: Indicate the country of the place to be protected; you can select the country from the countries box in the right as in above image for Country selection.
  • Then, select an answer (yes or no) for the following project conditions:

  1. New construction,
  2. Working place.


Note:

Number of Building to be protected = 1 because this free version is limited to one building only.




3- General Data Window


General Data Window


a- In this window, Enter building number.

Note: the building number is adjusted automatically to one in this free version of Riesgo.

b- Enter building name.

c- This window consists of (6) different sections as follows:

  1. Structure's dimensions section,
  2. Structure's Attributes section,
  3. Environmental influences section,
  4. Loss section,
  5. Service lines section,
  6. Existing protection measures section.


Some of these sections include boxes and different dropdown menus.




3.1 Structure's Dimensions Section

In this window, you will enter the following data:

  • Length (L): enter the length of the building to be protected.
  • Width (W): enter the length of the building to be protected.
  • Height of the roof (H): enter the height of the building to be protected.
  • Protrusion height (Hp): enter of the building’s Protrusion height to be protected.
  • Collection Area (Ad): it will be calculated automatically form the above data


Note:

You can manually set another value of the Collection Area (Ad) by check the box Manually set and write the required value.




3.2 Structure's Attributes Section

This section includes (4) dropdown menus as follows:

1- Type of roof dropdown menu

Select the type of the type of roof from the drop down menu which includes the following selections:
  • Metallic,
  • Concrete,
  • Flammable.


2- Type of structure dropdown menu

Ks1 is the Factor that considers the screening provided by the structure.

Select the type of the Type of structure from the drop down menu which includes the following selections:

  • Metallic: The structure provides a good screening to the equipment inside it. (Ks1 = 0,01). Reinforced concrete: The structure provides a certain screening to the equipment inside it. (Ks1 = 02).
  • Flammable: The structure provides no screening to the equipment inside it. (Ks1 = 1).
  • Concrete, brick: The structure provides no screening to the equipment inside it. (Ks1 = 1).


3- Risk of fire (Rf) dropdown menu

Select the type of the Risk of fire - factor Rf from the drop down menu which includes the following selections:

  • Low risk: stadium, railway station, telecommunication towers.. (Rf = 0,001).
  • Common: Office, factory, school, theatre, hotel, museum, shop.. (Rf = 0,01).
  • High: Paper mill, factory or warehouse with highly flammable products, wooden structure, thatched roof ... (Rf = 0,1).
  • Explosive: Powder magazine, silo, bakery, gas tank, petrochemical industry, fireworks factory.... (Rf = 1).


4- Internal wiring type dropdown menu

Screening Effectiveness of Internal Wiring- Ks3:  This affects the probability that lightning may cause a dangerous discharge or overvoltage.

Select the type of the Screening Effectiveness of Internal Wiring- Ks3 from the drop down menu which includes the following selections:

  • Unscreened: unscreened wiling with no specific routing precautions (Ks3=1,0).
  • Screened: cables with continuous screens or cable in metal conduit (earthed at both ends) (Ks3=0,1).





3.3 Environmental Influences Section

This section includes (3) dropdown menus as follows:

1- Location factor dropdown menu

Surrounding Location Factor- Cd: Height factor based on topography and relative height of surrounding structures or objects.

Select the Surrounding Location Factor- Cd from the drop down menu which includes the following selections:

  • Lower than: surrounded by higher structures (Cd=0,25).
  • Similar in height: surrounded by lower or similar height structures (Cd=0,5).
  • Isolated structure: no other structures within a distance of 3 times the height of the structure (Cd=1).
  • Exposed hilltop: exposed and isolated structure on hill top (Cd=2).


2- Environmental factor dropdown menu

Environmental factor- Ce: Spacing of 'drops' or nodes in the distribution of power or communication services.

Select the Environmental factor- Ce from the drop down menu which includes the following selections:

  • Tall buildings in a city (Ce=0).
  • Urban: typically, 75m to nearest distribution node (eg. Town or City) (Ce=0,1).
  • Suburban: residential, 500m to nearest distribution node (eg. Residential dwelling)(Ce=0,5).
  • Rural: typically, 1000m to nearest distribution node (eg. Rural) (Ce=1).



3- Type of soil dropdown menu

Type of soil is used to Estimate soil resistivity, Select the Type of soil from the drop down menu which includes the following selections:

  • Lime, clay, clayed sand: Low resistivity (50-500 ohm/m).
  • Soft rock: Normal resistivity (500-3000 ohm/m).
  • Granulated sand, gravel, hard rock: High resistivity (>3000 ohm/m).


4- Number of thunder days

Enter Number of thunder days in days/year for the location (country) where the building to be protected was located.

5- Ground flash density

Ground flash density in flashes/km2.year.this value will be calculated automatically from the entered data of Number of thunder days.

Note:

If the country in the project window was selected to be United States, a map shape will appear as in below image:


USA Map of Flash Density

and then you can do the following:

  1. Click on the map for locating the installation,
  2. Another window will open showing the states of USA, from this new window Click on the point where the structure to be protected is located, the UNE number will be shown which will be used to determine the Number of thunder days and Ground flash density,
  3. Click on the bar at the bottom of the form to continue.





3.4 Loss Section

This section includes (4) boxes as follows:

  1. Type-1 loss of human life,
  2. Type-2 loss of essential public services,
  3. Type-3 loss of cultural heritage,
  4. Type-4 Economic loss.


1- Type-1 loss of human life box

This box includes (4) dropdown menu as follows:

1.1 Due to fire dropdown menu

Fire Loss Factor - Lf1: Loss of human lives due to fire: Factor that takes into account the time of occupancy of the structures and the loss of lives that may occur.

Select the Fire Loss Factor - Lf1 from the drop down menu which includes the following selections:

  • Unoccupied: Warehouse, quarry, electrical substation, photovoltaic power plant, structure containing automated equipment (Lf1=0,01).
  • Sporadic occupancy: Stadium, church, leisure site , (Lf1=0,02).
  • Regularly occupied: School, factory, shop,... (Lf1=0,05).
  • Always occupied: Hospital, hotel, prison, residential building,... (Lf1=0,1).


1.2 Due to risk of panic dropdown menu

Special Hazard Factor – h1a:  According to the difficulties for evacuation and risk of panic.

Select the Special Hazard Factor – h1a from the drop down menu which includes the following selections:

  • Unoccupied:  (h1a=1 )
  • Low level of panic: Structures limited to 2 floors and less than 100 people: office, residential building,... (h1a=2).
  • Average level of panic or difficulties for evacuation: Theatres, concert hall, sporting events with between 100 to 1000 persons. Evacuation difficulties, structure with people without mobility, hospital, geriatric, nursery school, prison.... (hi a=5).
  • High level of panic: Theatres, concert halls, cultural & sporting events with more than 1000 people. (h1a=10).


1.3 Consequences of damage dropdown menu

Special hazards factor – h1b: Factor that takes into account not only possible losses of human life inside the structure but also other ones that may arise due to damages to the structure.

Select the Special hazards factor – h1b from the drop down menu which includes the following selections:

  • No consequences: No special hazard for persons outside the structure (h1b=1).
  • Hazardous risk to the surrounding environment: Storage of explosive, silos, airport control..... (h1b=20).
  • Contamination to the surrounding environment: Nuclear, petrochemical, structure containing toxic or radioactive substances (h1b=50).


1.4 Due to overvoltages dropdown menu

Overeoltaae Loss Factor – Lo1: Takes into account the loss of human lives that may be caused by a failure of the electric and electronic equipment.

Select the Overeoltaae Loss Factor – Lo1 from the drop down menu which includes the following selections:

  • Not relevant: The failure of the electric and electronic equipment causes no damage to people (Lo1=0).
  • Buildings with safety critical electrical systems: high use with elevators, sensors for avoiding risks in industries (Lo1=0.0001).
  • Vital electrical equipment: Hospital, structures with essential equipment for human life (Lo1=0.001).
  • Potentially explosive: structures where an electric failure may cause an explosion (Lo1=0.1).


2- Type-2 loss of essential public services box

This box includes (1) dropdown menu as follows:

2.1 Loss of services dropdown menu

Loss of services - L2:  This factor applies to structures offering essential public services.

Select the Loss of services - L2 from the drop down menu which includes the following selections:

  • Not relevant: Damages to the structure do not affect any essential service. (Lf2-Lo2=0).
  • Loss of service: Power supply, telecommunications, radio and TV, water, gas, railway, airport, hospital. (Lf2-Lo2=0,1).


3- Type-3 loss of cultural heritage box

This box includes (1) dropdown menu as follows:

3.1 Loss of cultural heritage dropdown menu

Loss of cultural heritage - Lf3: This factor applies to structures with significant cultural or heritage value.

Select the Loss of cultural heritage - Lf3 from the drop down menu which includes the following selections:

  • Not relevant: Damages to the structure do not involve loss of cultural heritage (Lf3=0).
  • Loss of cultural heritage: Museum, historic building, heritage goods ... (Lf3=0,1).


4- Type-4 Economic loss box

This box includes (5) dropdown menus as follows:

4.1 Special Hazards dropdown menu

Special Hazard Factor - h4: Factor that takes into account not only economic losses inside the structure but also other ones that may arise due to damages to the structure.

Select the Special Hazard Factor - h4 from the drop down menu which includes the following selections:

  • No consequences: No special risks (h4=1).
  • Hazard to the surrounding environment: storage of explosives, grain silos, air traffic control... (h4=20).
  • Contamination to the surrounding environment: Nuclear, petrochemical, structure containing toxic or radioactive substances (h4=50).


4.2 Due to fire dropdown menu

Fire Loss Factor - Lf4: Factor that takes into account the value of the structures and its contents.

Select the Fire Loss Factor - Lf4 from the drop down menu which includes the following selections:

  • Common value: Shop, house, ... (Lf4=0,1).
  • High value: Hotel, school, office, church, leisure site, ... (Lf4=0,2).
  • Very high value: Hospital, industry, museum, farm. (Lf4=0,5).


4.3 Due to overvoltages dropdown menu

Economic losses due to overvoltages - Lo4:  Factor that takes into account the value of the electric and electronic equipment inside the structure.

Select the Economic losses due to overvoltages - Lo4 from the drop down menu which includes the following selections:

  • Not relevant: Structures without electric and electronic equipment (Lo4=0).
  • Common value: Houses, small business, .. (Lo4=0,0001).
  • High value: Museum, farm, school, church, leisure site,... (Lo4=0,001).
  • Very high value: Hospital, industry, office, hotel, business centre... (Lo4=0,01).
  • Potentially explosive: structures where an electric failure may cause an explosion. (Lo4=0,1).


4.4 Due to Step/Touch voltages dropdown menu

Step and Touch Potential Damage Factor - Lt4:  Economic loss due to step and touch potentials. This relates to loss due to step and touch potentials inside, and up to 3m outside, the structure.

Select the Step and Touch Potential Damage Factor - Lt4 from the drop down menu which includes the following selections:

  • No shock risk (Lt4=0).
  • Livestock inside: Agricultural properties with animals inside the structure (Lt4=0,01). Livestock outside: Agricultural properties with animals outside the structure (Lt4=0,01).


4.5 Tolerable Risk dropdown menu

Tolerable Economic Loss Rt4: acceptable economic loss per year, Depends on building owner's requirements.

Select the Tolerable Economic Loss Rt4 from the drop down menu which includes the following selections:

  • 1 loss in 10 years.
  • 1 loss in 100 years.
  • 1 loss in 1000 years.
  • 1 loss in 10.000 years.
  • 1 loss in 100.000 years.


Note: Use default of 1 in 1000 years if unknown.




3.5 Service Lines Section

This section includes (3) boxes as follows:

  1. Power supply box,
  2. Other overhead services box,
  3. Other overhead services box.


1- Power supply box

This box includes (3) dropdown menus as follows:

1.1 Situation of the cable dropdown menu

This drop menu will determine the Power Line Type- PL. 
Select the Power Line Tyne- PL from the drop down menu which includes the following selections:

  • Overhead: Power distribution to the structure via overhead cable (PL=1).
  • Buried: Power distribution to the structure via underground cable (PL=2).
  • None: No power lines are connected to the structure (PL=0).


1.2 Type of cable dropdown menu

Type of external power cable- PLD0 and PLI0: Probability that a direct or indirect stoke to a power line will cause failure of electrical/electronic equipment. This is a function of the type of cabling in use.

Select the Type of external power cable- PLD0 and PLI0 from the drop down menu which includes the following selections:

  • Screened: cable with overall screen or cable in metal conduit (earthed at both ends)(PLD0=0,4) (PLIO=0,02).
  • Unscreened: no earthed screen around the cable (typical) (PLD0=1) (PLIO=1).


1.3 Transformer MV/LV dropdown menu

Transformer Factor – Ct:  Is there a supply transformer at the structure? Examples include: MV/LV transformer, isolation transformer or substation.

Select the Transformer Factor – Ct from the drop down menu which includes the following selections:

  • Transformer: (i.e. MV line) correction for overvoltages applied (Ct=0,2).
  • No Transformer: (i.e. LV line) no correction for overvoltages (Ct=1).


2- Other overhead services box

2.1 Number of services

Number of other overhead power supply services – Nuq:  For example, data or communication lines connected to the structure.

Note: Cables that follow the same physical routes are not considered as separate services.

This box includes (1) dropdown menu as follows:

2.2 Type of cable dropdown menu

Type of external power cabling - PLD1 and PLI1:  Probability that a direct or indirect stoke to a power line will cause failure of electrical/electronic equipment. This is a function of the type of cabling in use.

Select the Type of external power cabling - PLD1 and PLI1 from the drop down menu which includes the following selections:

  • Screened: cable with overall screen or cable in metal conduit (earthed at both ends)(PLD1=0,4) (PLI1=0,02).
  • Unscreened: no earthed screen around the cable (typical) (PLD1=1) (PLI1=1).


3- Other underground services box

3.1 Number of services

Number of other underground power supply services – Nuq:  For example, data or communication lines connected to the structure.

Note: Cables that follow the same physical routes are not considered as separate services.

This box includes (1) dropdown menu as follows:

3.2 Type of cable dropdown menu

Type of external power cabling - PLD2 and PLI2:  Probability that a direct or indirect stoke to a power line will cause failure of electrical/electronic equipment. This is a function of the type of cabling in use.

Select the Type of external power cabling - PLD2 and PLI2 from the drop down menu which includes the following selections:

  • Screened: cable with overall screen or cable in metal conduit (earthed at both ends) (PLD2=0,4) (PLI2=0,02).
  • Unscreened: no earthed screen around the cable (typical) (PLD2=1) (PLI2=1).





3.6 Existing Protection Measures Section

This section includes (2) dropdown menus as follows:

1- Class of the LPS dropdown menu

This drop menu will determine the Efficiency of lightning protection system on the structure- E.

Select the Efficiency of lightning protection system on the structure- E from the drop down menu which includes the following selections:

  • LPL I. (E=0,02).
  • LPL II. (E=0,05).
  • LPL Ill. (E=0,2).
  • LPL IV. (E=0).
  • No protection. (E=0).


2- Surge Protection dropdown menu

This drop menu will determine the Surge Protection Factor- SP.

Select the Surge Protection Factor- SP from the drop down menu which includes the following selections:

  • No surge protection installed (SP=0).
  • Equipotential bonding SPDs at entry points of service lines (SP=1).
  • Full surge protection system (SPD set as per IEC62305.4) (SP=2).





After entering and selecting all the general data, click Result button to perform Risk calculations and search the suitable protection measure.




4- Risk calculation window


Risk calculation window


This window includes (3) sections as follows:

1- Section of Determination of the need for protection according to UNE/EN 62305-2

This section will provide the following data:

  • Building number,
  • Building Name,
  • Collection area,
  • Risk of loss of human life,
  • Risk of loss of public services,
  • Risk of loss of cultural heritage,
  • Risk of economic losses,
  • Need of ELPS (external lightning protection system) installation,
  • Protection level,
  • Need of ILPS (internal lightning protection system) installation,
  • Type of ILPS.


Note:

If the risk values are greater than the tolerable risk, a list of protection measures is given. The user can select the protection measures that could be implemented or designed; the software recalculates the risk values.


2- Section of the protection technology

You can select the Protection to be designed and installed by:

  • ESE air terminals, or
  • Meshed conductors.


Note:

In case of choosing the protection with Early Streamer Emission (ESE) Air Terminals, the system will be designed according to the standards NF 17102 / UNE 21186 / NP 4426. In case of choosing protection with meshed conductors and simple rods, the system will be designed according to IEC 62305.


3- Section of Final Result

This section will provide the following data:

  • Name of Structure: the name of the building will appear here
  • Protection is: the need for lightning protection based on the risk calculations will appear here, it will be NECESSARY or UN-NECESSARY.
  • Lightning Protection Level: if the lightning protection is necessary, the required Lightning Protection Level will appear here.


Note:
If there is any missed project data, it will be written here for completion.






To download your copy of Riesgo Software Program, please click on the link.


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In the next Article, I will explain how to perform the Risk Assessment Study by using Excel Sheets Method. Please, keep following.




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