Lightning Risk Assessment Study
Lightning Risk assessment Study is actually the measure of risk of a lightning strike and probability of damages. It assesses the lightening risks to the facility according to international standards requirements.
These calculations are according to IEC Standard 62305-2.
All these calculations are based on:
- lightning strike density in that particular area (provided by OMV i.e. Ng = 8),
- Danger for people,
- Occupation coefficient of structure,
- Relative location of site,
- Fire Risk,
- Associated services,
- Electrical Lines,
- Lightning Protection Level,
- Surge Arrestor and
- Dimensions of installation.
Brief introduction of all are given below.
Lighting Strike Density (Ng)
It is the measure of lightning strikes per kilometre square per year in the particular area.
Higher the lighting strike density, higher the probability of lightning strike which needs higher level of lightning protection level.
Danger for People (h)
It is the factor of presence of people and panic in the building in case of a lightning strike.
|No particular danger||1|
|Low panic level(<=2 floors, < 100 persons||2|
|Medium risk of panic (< 1000 persons)||5|
|Difficult to evacuate (disabled people, hospitals)||5|
|High risk of panic (> 1000 persons)||10|
|Hazard for surroundings or environment||20|
|Contamination of surroundings or environment||50|
Occupancy Coefficient (Lf1)
It is the risk reduction factor with respect to theoccupancy of the building / installation. For example, loss due to lighting strike is higher in hospital as compared to a store / warehouse.
|Structure normally occupied||0.01|
Relative Location of Site (Cd)
It is the risk reduction factor with respect to the location and surrounding of the building / installation. For example, chance of lighting strike is minimized if the building is near to a high tower.
|Structure surrounded by higher objects or trees||0.25|
|Structure surrounded by similar or lower objects||0.5|
|Isolated structure-No other objects nearby||1|
|Isolated structure on top of a hill or a hillock||2|
Fire Risk (rf)
It is the risk reduction factor with respect to the flammability of the material present in the building / installation. For example, in case of lighting strike, loss will be very high at a gas station as compare to the cement store.
Continue reading in Manual (available for download below)
|Software:||Lightning Protection Risk Assessment Calculator|
|Download:||Right here | Get Download Updates | Get Technical articles|
|Manual:||Right here | Get Download Updates | Get Technical articles|