lightning protection calculation
TRANSCRIPT
LIGHTNING CALCULATION FOR TG BUILDING
Width of Building L = 36 mDepth of building W = 28 mHeight of building H = 23 m
23
.00
=(L X W) + 2 x (L x H) +
2 x (W+H) + pH2 sqm
= 5613.90 sqm
Probable Number of strikes to the structure per year
P = Ac x Ng x 10-6
Isokeronic Level = 73Annual
thunderstorm daysLightning flash density (Clause 8.1.2 and fig1 IS: 2309
Ng = 6.9Lightning flashes /
sqkm / year
P = 0.038735927Lightning flashes /
year
= 0.000010
Use of Structure A = 1 Table 1, 1AType of Construction B = 1 Table 1, BConsequential Effects C = 1 Table 1, 1CDegree of Isolation D = 1 Table 1, 1DType of Country E = 0.3 Table 1, 1E
= A x B x C x D x E= 0.3
= P x A x B x C x D x E= 1.162E-02
Protection Needed
= 20 mFigure 5
= 10 mFigure 5
= 2 m
= 3 m
= 25X6 GI Strip Table 4
= 1008 m= 5 Nos
= 128 m= 5 Nos
= 5 Nos
= 25x6 GI Strip Table 4
Overall Risk Factor
Size of Horizontal Conductor
Number of Down conductor is considered to be following : (as per cl:12.2.3 of IS 2309) i)one plus an additional one for each 300 sq.mm ;or part thereof,in excess of the first 100 sq.mm. ii)one for each 30m of perimeter of the structures protected.
No of Down Conductors
Result: -
Overall weightage
Acceptable Risk (Po)
Collection Area Ac
Weighting Factors
ELEVATION
PLAN
28.00
36
.00
No of Down Conductors
No of down conductors to be considered (minimum of the above two)
Size of Down Conductor
Max spacing between conductors width wiseMax spacing between conductors depth wise
Minimum no of Conductors width wise including periphery conductorsMinimum no of Conductors depth wise including periphery conductors
Base Area
Perimeter
LIGHTNING CALCULATION FOR COOLING TOWER
Width of Building L = 40 mDepth of building W = 15 mHeight of building H = 12 m
12
.00
=(L X W) + 2 x (L x H) +
2 x (W+H) + pH2 sqm
= 2372.39 sqm
Probable Number of strikes to the structure per year
P = Ac x Ng x 10-6
Isokeronic Level = 73Annual
thunderstorm daysLightning flash density (Clause 8.1.2 and fig1 IS: 2309
Ng = 6.9Lightning flashes /
sqkm / year
P = 0.016369486Lightning flashes /
year
= 0.000010
Use of Structure A = 1 Table 1, 1AType of Construction B = 1 Table 1, BConsequential Effects C = 1 Table 1, 1CDegree of Isolation D = 1 Table 1, 1DType of Country E = 0.3 Table 1, 1E
= A x B x C x D x E= 0.3
= P x A x B x C x D x E= 4.911E-03
Protection Needed
= 20 mFigure 5
= 10 mFigure 5
= 2 m
= 2 m
= 25X6 GI Strip Table 4
= 600 m= 3 Nos
= 110 m= 4 Nos
= 3 Nos
= 25x6 GI Strip Table 4
Overall Risk Factor
Size of Horizontal Conductor
Number of Down conductor is considered to be following : (as per cl:12.2.3 of IS 2309) i)one plus an additional one for each 300 sq.mm ;or part thereof,in excess of the first 100 sq.mm. ii)one for each 30m of perimeter of the structures protected.
No of Down Conductors
Result: -
Overall weightage
Acceptable Risk (Po)
Collection Area Ac
Weighting Factors
ELEVATION
PLAN
15.00
40
.00
No of Down Conductors
No of down conductors to be considered (minimum of the above two)
Size of Down Conductor
Max spacing between conductors width wiseMax spacing between conductors depth wise
Minimum no of Conductors width wise including periphery conductorsMinimum no of Conductors depth wise including periphery conductors
Base Area
Perimeter
LIGHTNING CALCULATION FOR BOILER
Width of Building L = 33 mDepth of building W = 20 mHeight of building H = 50 m
50
.00
=(L X W) + 2 x (L x H) +
2 x (W+H) + pH2 sqm
= 13813.98 sqm
Probable Number of strikes to the structure per year
P = Ac x Ng x 10-6
Isokeronic Level = 73Annual
thunderstorm daysLightning flash density (Clause 8.1.2 and fig1 IS: 2309
Ng = 6.9Lightning flashes /
sqkm / year
P = 0.095316473Lightning flashes /
year
= 0.000010
Use of Structure A = 1 Table 1, 1AType of Construction B = 0.2 Table 1, BConsequential Effects C = 1 Table 1, 1CDegree of Isolation D = 1 Table 1, 1DType of Country E = 0.3 Table 1, 1E
= A x B x C x D x E= 0.06
= P x A x B x C x D x E= 5.719E-03
Protection Needed
= 20 mFigure 5
= 10 mFigure 5
= 2 m
= 2 m
= 25X6 GI Strip Table 4
= 660 m= 4 Nos
= 106 m= 4 Nos
= 4 Nos
= 25x6 GI Strip Table 4
No of Down Conductors
No of down conductors to be considered (minimum of the above two)
Size of Down Conductor
ELEVATION
PLAN
20.00
Max spacing between conductors width wiseMax spacing between conductors depth wise
Minimum no of Conductors width wise including periphery conductorsMinimum no of Conductors depth wise including periphery conductors
Base Area
Perimeter
Size of Horizontal Conductor
Number of Down conductor is considered to be following : (as per cl:12.2.3 of IS 2309) i)one plus an additional one for each 300 sq.mm ;or part thereof,in excess of the first 100 sq.mm. ii)one for each 30m of perimeter of the structures protected.
No of Down Conductors
33
.00
Result: -
Overall weightage
Acceptable Risk (Po)
Collection Area Ac
Weighting Factors
Overall Risk Factor