Building / Structure Lighting Protection Calculations
Calculations As per IS-2309 Jignesh.N.Parmar, www.electricalnotes.wordpress.com Area of Building / Structure:
Length of the Building : (L) 80.42 Meter
Width of the Building :(W) 24.40 Meter
Height of the Building: (H) 23.00 Meter
Lightning Flash Density:
Number of Thunderstorm: (N) 80.00 Days/Year
6.9 km2/Year
Application of Structure :(A) Houses & Buildings with outside aerial 0.7
Type of Constructions :(B) Reinforced concrete without Metal Roof 0.4
Conteats or Consequential Effects: (C) Power stations / Gas works 1
Degree of Isolations: (D) Structure in a large area having greater height 0.4
Type of Country: (E) Flat country at any level 0.3
Maximum Acceptable Overall Risk Factor 0.000001 >
Calculations:
Collection Area: (Ac) 8445.028
Probable No of Strikes to Building / Structure :(P) 0.0582706932 No's/Year
Overall Multiplying Factor : (M) 0.03360
Overall Risk Factor Calculated: (xc) 0.00195789529152
Base Area of Structure:
Base Area of Structure: ( Ab) 1962.248
Perimeter of Structure: (P) 209.64 Meter
Base Area (Ab) > 100 Meter2 Yes >
Results:
Calculated Overall Risk Factor Calculated > Maximum Acceptable Overall Risk Factor
Lightning Protection is Required.
1No's of Down Conductors:
Down Conductors As per Base Area of Structure:(s) 7 No's
Down Conductors As per Parimeter of Structure: (t) 7 No's
Required No's of Down Conductors 7 No's
Lightning Flash Density : (Ng)
Meter2
Meter2
Referance Table As per IS:2309
Thunder Storm Days / Year 5
10 20 30 40 50 60 80 100
Application of Structure Houses & Buildings
Houses & Buildings with outside aerial Factories / workshop/ Laboratories Office blocks / Hotel
Block of Flats / Residences Building
Churches/ Hall / Theatres / Museums, Exhibitions Departmental stores / Post Offices
Stations / Airports / Stadium
Schools / Hospitals / Children's Home Others
Type of Constructions Steel framed encased without Metal Roof Reinforced concrete without Metal Roof Steel framed encased with Metal Roof Reinforced concrete with Metal Roof
Brick / Plain concrete or masonry without Metal Roof Timber framed or clad without Metal Roof
Brick / Plain concrete or masonry with Metal Roof Timber framed or clad with Metal Roof
Conteats or Consequential Effects Domestic / Office Buildings
Factories / Workshop
Industrial & Agricultural Buildings Power stations / Gas works
Telephone exchange / Radio Station Industrial key plants, Ancient monuments Historic Buildings / Museums / Art Gallaries Schools / hoapitals / Childern Homes
Structure in a large area having greater height Structure located in a area of the same height Structure completely Isolated
Type of Country Flat country at any level
Hill country
Mountain country between 300m and 900m Mountain country above 900m
Referance Table As per IS:2309
0.2 0.5 1.1 1.9 2.8 3.7 4.7 6.9 9.2
Factor 0.3 0.7 1 1.2 1.2 1.3 1.3 1.3 1.7 1.2
Factor 0.2 0.4 0.8 1 1.4 1.7 2
Factor 0.3 0.3 0.8 1 1 1.3 1.3 1.7
Lightning Flash Density (Flashes to Ground /km2/year)
0.4 1 2
Factor 0.3
1 1.3 1.7
