Ramón Silva Masdeu is an Electrical engineer and a member of INGESCO’s Team since 1995. He has more than 25 years of experience in the lightning protection field.
Risk Management for a Building
The first step to protect a building is to calculate its risk following the IEC 62305-2 standard. In case the building needs lightning protection, we should calculate its level (LPL).
INGESCO, a company specialised in protection and prevention against lightning has developed free online software for this purpose that generates a technical report with all the calculus and the solution for proper protection.
https://calculus.ingesco.com/en/
Once we know the LPL of our facilities, we will choose the best system (simple rod, faraday cage, etc) for external protection against direct strikes. In the same way, we will install SPDs (surge protection devices) in the electrical panels to protect all electronic devices.
Disaster Risk Reduction
In 2015, the United Nations Office for Disaster Risk Reduction published the Sendai Framework for Disaster Risk Reduction 2015-2030, to develop initiatives that can bring a substantial reduction of disaster risk and losses in lives, livelihoods, health, and in the economic, physical, social, cultural, and environmental assets of persons, businesses, communities, and countries.
Lightning is one of the risks to human beings and can be reduced by applying protection and prevention measures.
India is one of the countries with more lightning activity. There are different climates in the country (semi-arid, coastal, island, hilly, inland, and oceanic) and this affects the number of thunderstorms and lightning in the different regions. In general, the Eastern region in the monsoon season has more thunderstorms and lightning activities than the Western region. More lightning is detected in the Northeastern region due to the complex topography of the Garo-Khasi, Arakan Yoma and Patkai Hills.
What is lightning?
Lightning is a giant spark of electricity of millions of volts in the atmosphere between clouds or between a cloud and the ground.
Lightning current can reach a value of up to 200 kA and a temperature of 50,000°F in a few milliseconds.
How can lightning affect people?
People who are outside of a structure are more exposed to the risk of being struck by lightning.
People who are inside of a building can also be exposed to hazards such as:
- The sharp increase in potential of power lines from the electrical broad, such as power lines, telephone cables or antenna elements.
- Metal objects inside a structure that can also reach high potential and contact stresses.
Possible injuries
When a human being is directly struck by lightning, the voltage climbs up to about 300 kV (100 kV to 500 kV) from head to toe.
A larger portion of the lightning current does not flow through the body but on its surface. Due to this effect, many people survive after a direct lightning strike.
Physiological effects range from being dazzled to almost instantaneous death (full cardiac arrest), neurological troubles, visual loss or cataract, deafness or ruptured eardrum, paralysis, temporary fainting (sometimes with short respiratory arrest) and short or long duration comas.
How injured people can be helped
Call the emergency services immediately and obtain medical help. First aid can be life-saving.
The emergency treatment shall be appropriate to the level of injury.
Lightning injuries can generally be grouped into three classes of severity: mild, moderate, and severe. The mildly injured person is often just stunned by the lightning strike. He is usually awake though confused and amnesic of the event.
What to do outdoors
Although there is a higher probability of a lightning strike to tall objects like trees or masts, do not forget that it may strike anywhere. When the possibility of a thunderstorm is great, follow the precautions below:
Avoid mountain climbing. Do not walk close to rivers and, more importantly, do not swim during a thunderstorm. Avoid horse riding, the use of a bicycle, motorcycle, convertible car or other open conveyance, a tractor or harvester (farmers have been struck by lightning).
Do not use sailing boats (unless properly protected against lightning), tents, open picnic pavilions, trams with open windows.
In the countryside, move away quickly from high points, do not stay in a group. In towns, walk into a store or a public building where you are protected. Move away from streetlights, towers, and metallic fences as well as isolated trees.
Do not use umbrellas or golf clubs or hold long metallic or other conducting objects in your hands.
Hazardous situation in a car
A metallic car constitutes good protection (Faraday-like shield) if windows are wound up. As a good electrical conductor, a car keeps the passengers protected against lightning.
Nevertheless, it is advisable to drive carefully (at a moderate speed) in a thunderstorm.
Vehicles with fibreglass bodywork (e.g. mobile homes) as well as convertibles without a roof metallic framework or roll bar, offer far lower protection.
Dangers associated with driving a car in a thunderstorm include:
the vehicle can be damaged through the tyres due to the transfer of heat and puncturing.
caused by the lightning current; tyres have no protecting effect.
metallic parts should not be touched while sitting in the car as they may transmit a high voltage.
electronics can be disturbed by the electromagnetic field.
What to do when playing outdoor sports
People involved in outdoor sports activities should seek a safe location at the first sign of lightning or thunder in the area. Coaches and/or game officials should terminate games or practices at the first sign of thunder or sighting of lightning.
Players and coaches should seek shelter in buildings with lightning protection systems or in closed metallic vehicles. Play may be resumed 30 minutes after the last thunder is heard or lightning flash is seen.
What to do at open air festivals
The same elementary rules apply to open air events as for other outdoors activities. In principle, spectators sitting or standing on open platforms are endangered. When a thunderstorm approaches, they should move to lightning-protected areas. Platforms equippedwith a lightning protection system or covered with a roof made of metal or reinforced concrete are regarded as protected areas.
No metallic parts, columns, walls, crowd barriers should be touched. Keep at least 1 metre and preferably, 3 metres away from all these and other conductive parts.
Where to find safe locations
The safest location to seek shelter is inside a building equipped with lightning protection systems (external and internal). For homes without lightning protection, it is advisable to close doors and windows to repel air streams, to sit away from the fireside or other chimneys, and to avoid using water where the structure is equipped with metallic water pipes.
Avoid open spaces such as balconies.
Use mobile phones and cordless telephones. Do not call from a corded phone.
How to protect your house and its contents from lightning
Following the IEC 62305 series, after having calculated the risk, we will have to apply the necessary protection measures. They are divided in two parts (Photo 4):
- LPS (Lightning Protection System)
- SPM (Surge Protection Measures)
Lightning Protection and Prevention Systems
A system of absolute protection against lightning is mainly composed of protection and prevention systems, depending on their functionality (see Photo 4):
External System: This includes various systems used to cover structures or buildings, open spaces and people against direct lightning strikes areas.
Internal System: Systems are SPDs (Surge Protection Devices) suitable for safeguarding facilities and networks connected to electricity, telephone, and data communication equipment.
Preventive System: Systems to detect lightning or storms and give an alarm warning signal. IEC 62793:2020
Thunderstorm Warning Systems: Protection against lightning.
Two Types of External Protection:
Passive Protection Systems: It is a protection system that does not perform any prior action to lightning strike. Its functionality is executed when lightning strikes the structure in charge of driving and dissipate the energy of lightning to the ground.
Active Protection Systems: This system performs pre-action to the lightning strike; the priming system emits an ionisation creating a shock return to the cloud- directed channelling and directing the beam to a safe and ready-for-download point.
Active protection offers several advantages over other types of protection:
Protects not only the structure, but also around open areas.
Ease of installation, reducing the price of labour. It is much cheaper and needs less raw materials.
Less visual impact, having a less bulky installation, protected building aesthetically not altered significantly. The entire installation is called Lightning Protection System (LPS).
Another very important part of the LPS and the SPM is the earthing system, that must be designed following the criteria of current regulations, for example, IEC 62305-3:2010
Protection Against Lightning
Part 3: Physical damage to structures and life hazards and IEC 62305-4:2010
Part 4: Electrical and electronic systems within structures.
Prevention through a Thunderstorm Warning System
To prevent is to reduce risks.
The main objective of prevention related to natural phenomenon is to reduce the loss of human lives and reduce the damage to economic activities. It is necessary to be conscientious of the prevention need.
Atmospheric electrical discharges during thunderstorms are responsible for a considerable number of loses. Some statistics count these accidents in tens of thousands each year. Material damages caused by lightning bolts are also costly and sometimes lead to a partial or total shutdown of essential activities.
The definition and application of preventive action protocols when there is risk of lightning strikes as well as the increasing use of thunderstorm warning systems are helping to significantly reduce the number of accidents related to this natural phenomenon.
A Thunderstorm Warning System (TWS) operates under the principle of the “electric field mill” to continuously measure the intensity of the atmospheric electric field. The real-time processing methods and algorithms included in this system allow the user to determine when the risk of lightning strikes occurrence increases or decreases. The operating parameters that control the generation of alarms, as well as the calibration of the sensor according to the installation site, are fully customisable.
They can be used both as an autonomous system and as part of other more complex integrative systems.
They also support isolated relay outputs that allow, among other actions, the activation of light and acoustic signals, that enable to differentiate the start and end moments from the periods of high risk of lightning strike occurrence.
Advantages of a TWS:
Provides information about the existence of risk of lightning strike before the first discharge occurs.
Helps determine the time of completion of the thunderstorm based on the risk of lightning strike occurrence.
Contributes to ensure the protection of lives and material goods by generating reliable decision-making support information in the implementation of preventive measures.
Detects atmospheric discharges within its detection radius.
Some models have heating system to prevent freezing, which is highly suitable to use in locations where snow accumulation makes it impossible to work with other types of system.
References:
Indian Lightning Protection Standards
From the Bureau of Indian Standards, we find the following:
- IS/IEC/TR 60479 – Part 4:2004 – Effects of Lightning Strokes on Human Beings and Livestock
- IS/IEC 61400 – Part 24:2010 – Wind Turbines Part 24 Lightning Protection
- IS 62305 – Part 1: 2010 – (Reaffirmed Year: 2020) – Protection Against Lightning – Part 1 General Principles
- IS/IEC 62305 – Part 2:2010 (Reaffirmed Year: 2019) – Protection Against Lightning – Part 2 Risk Management
- IS/IEC 62305 – Part 3:2010 (Reaffirmed Year: 2020) – Protection Against Lightning – Part 3 Physical Damage to Structures and Life Hazard
- IS/IEC 62305 – Part 4:2010 (Reaffirmed Year: 2020)- Protection Against Lightning – Part 4 Electrical and Electronic Systems Within Structures
For further information please visit the INGESCO website, where you can see a list of international standards related to lightning protection and lightning components for an installation: https://www.ingesco.com/en/noticias/lightning-protection-standards#internacionales
