Lightning Calculations
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LIGHTNING CALCULATION CLIENT
: ACC WADI – LIMITED
REV/DATE
: 0/18.07.05
PROJECT
: LIGHTNING ARRESTOR REQUIREMENT CALCULATION
PRE/CHKD
: LB/ MK
TITLE
:LIGHTNING CALCULATION
SHEET
: Page 1 of 48
CONTENTS
SL.NO.
DESCRIPTION
SHEET NO.
1.0
PURPOSE
2
2.0
REFERENCES DOCUMENTS
2
3.0
ASSUMPTIONS
2
4.0
RISK FACTOR CALCULATION
7
5.0
STRIP SIZE CALCULATION
32
6.0
RESULT
46
LIGHTNING CALCULATION CLIENT
: ACC – LIMITED
REV/DATE
: 0 /24.06.05
PROJECT
: LIGHTNING ARRESTOR REQUIREMENT CALCULATION
PRE/CHKD
: LB/ MK
TITLE
: LIGHTINING CALCULATION
SHEET
: Page 2 of 48
1.0
PURPOSE The calculations are done for the following purposes :
a) Lightning protection requirement for Old wadi Cement plant,Power plant and Colony Area. b) To estimate the number of Lightning electrodes required at the above area. c) To prove that the maximum value of resistance of the earthing system shall not be more than 3 ohms as per 12.3.1 of IS 2309:1989 . 2.0
REFERENCE DOCUMENTS, CODES AND STANDARDS
a) NFPA78.
IS: 2309-1989-Indian Standard Code of Practice for Protection against Lightning.&
ASSUMPTIONS
& RECOMMENDED DESIGN PROCEDURE.
a) Soil resistively is equal to 312 ohm-m , which is assumed to be uniform throughout the plant. b) Pipe electrode in contact with earth is 300 cm and the diameter of the pipe electrode is 3.8 cm . c) The effect of interconnection and links between other earthing grids is ignored for the purpose of this calculation. 3.1
Protected Structure Common structures are structures used for ordinary whether commercial, Industrial, institutional or research.
3.2
Need for Protection
3.2.1Desirability of providing lightning protection shall be assessed either by calculating the risk
index or by judgement. Structures with inherent explosive risks like factories, fuel tanks etc. need the highest possible class of lightning protection system. Other structures where large number of people congregate, essential public services are concerned, tall/isolated structures, structures of historic and cultural importance should be provided with lightning protection system irrespective of risk index.
3.2.2 Risk Index – Weighting Factors Indian standard recommends the following factors which form the basis of calculating the risk index. a) Weighting factor A – Use of structure (Table 1 A). b) Weighting factor B – Type of Construction (Table 1 B) c) Weighting factor C – Contents or consequential effects (Table 1C) d) Weighting factor D – Degree of Isolation (Table 1D) e) Weighting factor E – Type of Country (Table 1E)
Depending upon the characteristic features of above factors, various weighting factors are given in Table 1A to 1E of IS:2309. The probability of the structure being struck by lightning in one
LIGHTNING CALCULATION CLIENT
: ACC – LIMITED
REV/DATE
: 0 /24.06.05
PROJECT
: LIGHTNING ARRESTOR REQUIREMENT CALCULATION
PRE/CHKD
: LB/ MK
TITLE
: LIGHTINING CALCULATION
SHEET
: Page 3 of 48
year is the product of “lightning flash density “ and the “effective collection area “ of the structure to be protected. The probable number of strikes/year (Risk) is: P = Ac * Ng * 10 –6 Ng = Number of lightning flashes to ground per Km 2 per year. Ac = Effective area of collection of the structure. Risk, P, multiplied by weighting factors A to E gives the risk index. 3.2.3
If the value of risk index is less than 10 -5, then in the absence of other Overriding consideration, protection shall not be necessary. 3.2.4 If the risk index is more than 10 -5 then sound reasons shall be necessary to Support the decision of not providing the lightning protection. 3.3
3.3.1 3.3.2
Size and Material of Conductors The materials of air termination network, down conductors and earth terminals shall be GI as per Table 3 of IS 2309:1989. Lightning currents have very short duration. Therefore, thermal factors are of little consequence in deciding the cross-section of the conductor. The minimum size of the various components of the system are given below: Sl.No 1.
2.
Item Vertical Air Terminations
Material Copper
20 mm dia,1000 mm Long
G.S
20 mm dia,1000 mm Long
Horizantal air Terminations copper G.S
3.
Down Conductors
4.
Earth Terminations a) Horizontal conductors b) Rod Electrodes c)Pipe Electrode
Size
20 X 3 mm Flat 25X 6mm Flat.
Same as Horizontal Air Terminations.
Cu. Strip G.S Strip Cu Steel Steel
32 X 6 mm 50 X 6 mm 20mmDia, 3000 mm Long. 20mmDia, 3000 mm Long. 40mmDia, 3000 mm Long.
LIGHTNING CALCULATION CLIENT
: ACC – LIMITED
REV/DATE
: 0 /24.06.05
PROJECT
: LIGHTNING ARRESTOR REQUIREMENT CALCULATION
PRE/CHKD
: LB/ MK
TITLE
: LIGHTINING CALCULATION
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3.4
Air termination Systems Air Terminations: The vertical and horizontal conductors or combination of both, installed over or near the structure to attract the lightning stroke to themselves are called air terminations.
3.4.2
Protective Zone : The space around the air terminations in which there is almost no probability Direct lightning discharge is called the protective zone of air termination. Protective zones of various arrangements shall be as given in IS: 2309 - 1989 etc. for correctness.
3.4.3
The angle between vertical line passing through the conductor and side of protective zone is called protective angle.
3.4.4
Horizontal air terminations: Arranged along the contours such as parapets, ridges and edges of the roof and wherever necessary, over the flat surfaces, horizontal air termination network form basic protection arrangement, if roof of the building has large horizontal dimensions.
3.4.5 Protective angle of horizontal air termination is 45° for normal protection and upto 30° if higher protection is needed.
3.4.6 Protective angle for two horizontal air terminations, spaced at a distance not greater than twice the height, shall be used within the space between conductors and 45° and 30° respectively if higher protection is needed.
3.4.7 The spacing, between adjacent horizontal air terminations shall not be more than 10 metres and no part of the roof shall be more than 5 metres away from the nearest horizontal conductor. 3.4.8 Layout of Horizontal Air Terminations a) A horizontal air termination shall run along the periphery of the roof. b) Additional parallel horizontal conductors shall be provided if spacing between the conductors is more than 10 metres or any part of the roof is more than 5 metres away from the nearest horizontal conductor. C) Conductors shall be interconnected to form a closed loop. 3.4.9 Vertical Air Terminations a) Vertical air terminations shall be used for very high structures with small base area. b) Protective angles of vertical air terminations shall be same as given for horizontal air terminations under clause 3.4.5/.6. c) Vertical air terminations shall project at least 300 mm above the protected structure. d) All the vertical air terminations provided on the same structure shall be interconnected. e) All the air termination network shall be effectively secured to the roof against overturning. The fasteners shall be of the same material as the conductor to avoid bimetallic corrosion.
3.4.10
Where a structure has two elevations, out of which lower is projecting outside the higher elevation such that the network in higher elevation does not protect the lower elevation, both networks shall be interconnected by connecting the higher elevation down conductors to the lower network.
LIGHTNING CALCULATION CLIENT
: ACC – LIMITED
REV/DATE
: 0 /24.06.05
PROJECT
: LIGHTNING ARRESTOR REQUIREMENT CALCULATION
PRE/CHKD
: LB/ MK
TITLE
: LIGHTINING CALCULATION
SHEET
: Page 5 of 48
3.4.11
If a particular small portion in the structure is projecting above the level of horizontal conductors by more than 1000 mm, a separate network shall be formed for the same.
3.4.12
All the metal piping, railing, etc. on the roof shall be bonded to the protective network with a bolted connection.
3.5 Down Conductors The conductors which connect air terminations to earth terminations are called down Conductors. 3.5.1 Size and material of the down conductors shall be given under clause 3.3. 3.5.2 Number a) As per IS.2039, a structure having a base area less than 100 sq. mtr shall be provided with only one down conductor. Chimneys, whose over all width at the top or diameter is less than 1.5 metres shall be provided with only one down conductor. b) For buildings having base area more than 100 m 2 , the number of down conductors shall be smaller the number obtained by the following two criteria i) one down conductor for first 100 m 2 area plus one for every additional 300 m 2 area or part thereof ii) one down conductor for every 30 metres of periphery Non-conducting chimneys whose overall width at the top or diameter is more than 1.5 metres shall be provided two down conductors. Structures on rocky terrain where testing and inspection is difficult shall be provided with minimum two down conductors. As per BS: 6651 1999 at least one down conductor should be provided for each 20 mtr or part thereof of the perimeter at roof level. Structures greater than 20-mtr height, shall have a down conductor per 10 mtr or part thereof. 3.5.3 Route of Down Conductors a) Unless aesthetic and architectural considerations prohibit, down conductors shall be uniformly distributed around the outside walls of the structure. b) The path between the air terminations and earth terminations shall be as direct as possible and shall avoid sharp bends upturns and kinks. c) No deep re-entrant loop, in which length of the conductor forming the loop is more than 8 times the width of open side of the loop, shall be recommended. This is shown in Figure-1 and is avoided to prevent large inductive voltage drop across the open side of the loop. d) In a building cantilevered from first storey onwards, the down conductors shall not follow the contour of the building as shown in Figure-2. e) Down conductors shall not be attached to lift shafts.
LIGHTNING CALCULATION CLIENT
: ACC – LIMITED
REV/DATE
: 0 /24.06.05
PROJECT
: LIGHTNING ARRESTOR REQUIREMENT CALCULATION
PRE/CHKD
: LB/ MK
TITLE
: LIGHTINING CALCULATION
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: Page 6 of 48
f) When suitable external route for down conductors is not possible or advisable, the conductors may run in air space provided by non-metallic, non-combustible ducts not smaller than 75 x 15 mm or in any vertical, service duct running through the height of the building, provided it does not contain any unarmoured, non-metal sheath cable. g) Down conductors may be embedded in the wall of the structure. In such case, reinforcing bars shall be bonded to the down conductor. h) In case metallic object such as pipes, structures etc. exists in the vicinity of down conductors, there is a risk of side flash over between the down conductor and these objects. In such cases, the object shall be bonded to or installed on the basis of the recommendations given under Clause3.7.1. Each down conductor shall be provided with testing point as discussed in Clause 3.7.2 (f) j)Holes in cornice and parapet walls shall be used for the passage of down conductors, wherever possible.
3.6Earth Terminations 3.6.1 Earthing conductors embedded in the soil and designed for the safe discharge of lightning currents into the soil are called earth terminals. 3.6.2 Down conductor shall be provided an earth electrode and all earth electrodes shall be interconnected.’
3.6.3 Earthing resistance of earth terminations shall be such that the combined resistance is not more than 3 ohms. In case, the earthing resistance is not within limits, the earth electrodes shall be located in treated earth pit. 3.6.4 Disconnecting facility shall be provided in some of the earth electrodes so that it is possible to measure the earthing resistance. 3.6.5 Lightning protective earthing system may be interconnected with operational and safety earthing system. 3.6.6 Earthing conductors shall not be more than 1.5 to 2.0 metres away from the structure except when high temperatures are likely to be encountered in subsoil or when sufficient space near the structure is not available. 3.6.7 Metal pipes and other structures buried in earth shall be bonded to or isolated from the earthing conductors on the basis of the recommendation given under clause 3.7.1. 3.6.7 Earth Electrodes a) The use of rod/pipe/plate electrodes is permissible. their choice will depend upon the site conditions, soil resistivity and economic considerations. In general, the use of pipe electrodes is recommended. b) The material of earth electrodes shall be either galvanised steel or copper. The choice will depend upon the material of the air termination, down conductors and soil resistivity. It is preferable to use the same material throughout the system.
LIGHTNING CALCULATION CLIENT
: ACC – LIMITED
REV/DATE
: 0 /24.06.05
PROJECT
: LIGHTNING ARRESTOR REQUIREMENT CALCULATION
PRE/CHKD
: LB/ MK
TITLE
: LIGHTINING CALCULATION
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Horizontally buried interconnecting conductors shall be laid at minimum 600 mm depth. Earthing system shall be in accordance with IS: 3043.Minimum spacing between rod/pipe electrodes and plate electrodes shall be 6 and 8 metres respectively.
4.0
Lightning protection for structure- Evaluation of lightning flash density,collection area of structure and overall risk factor.
4.1
Evaluation of lightning ground flash density: The lightning ground flash density can be estimated using the following formula indicated in IEC 61024-1-1. Lightning groung flash density Ng=0.04x(Td)
1.25
per Km2 per year
Where Td is the number of thunderstorm days per year In Gulbarga the Annual thunderstorm days is 34 days( As per IS 2309:1989 Page number 5).Therefore the lightning ground flash density per Km2 per year is calculated using the above formula as follows Ng=0.04x(34)
1.25
=3.284 per Km2 per year which is commen throughout the plant area 4.2
Evaluation of probable No of strikes for the structure per year P: Probable No of strikes for the structure per year P can be calculated using the formula P= Ng x Ac x 10
–6
per year
Where Ac is the equivalent collection area of structures on a plain surface. Ac=(L XB)+2(L X H)+2(B X H)+
π H2
For complex structure it can be calculated based on the guidelines given in item 4.2 of IEC 61024-1-1 standard. The risk factor P is multiplied by the product of the weighting factors( Table 1A-1E of IS 2309:1989). If the overall risk factor is greater than 10-5 protection is required for the structure. Calculation for the overall risk factor is done below for each building in the Old Wadi Cement plant, Colony and Power plant.
OLD WADI CEMENT PLANT
LIGHTNING CALCULATION CLIENT
: ACC – LIMITED
REV/DATE
: 0 /24.06.05
PROJECT
: LIGHTNING ARRESTOR REQUIREMENT CALCULATION
PRE/CHKD
: LB/ MK
TITLE
: LIGHTINING CALCULATION
SHEET
: Page 8 of 48
BULK LOADING SILO: Diameter(D)
: 11 M
Height (H)
: 49.5 M
Lightning Flashes/Sq.Km / year(Ng) -Rating factor for Wadi
: 3.284 (AS CALCULATED ABOVE)
Weighing Factors A
: 1.0
B
: 0.8
C
: 0.8
D
: 1.0
E
: 0.3
Overall weighing Factors
:AxBxCxDxE : 1.0 x 0.8 x 0.8 x 1.0 x 0.3 : 0.192
Collection Area AC
:
π H2
:
π (49.5) 2 2
: 7693.785 m
6
Probable no.of strikes for the
: Ac x Ng x 10-
structure per year P
: 7693.785 x 3.284 x 10-
6
: Therefore, the overall risk Factor
2.526 x 10-2
: P x Overall Weighing Factor : 2.526 x 10-2 x 0.192 3
: 4.84 x 10- which is greater than 10Therefore for Bulk loading Silo Lightning Protection is essential. CEMENT STORAGE SILO: Diameter(D)
: 10 M
Height (H)
: 29.8 M
Lightning Flashes/Sq.Km / year(Ng) - Rating factor for Wadi
: 3.284
Weighing Factors
5
LIGHTNING CALCULATION CLIENT
: ACC – LIMITED
REV/DATE
: 0 /24.06.05
PROJECT
: LIGHTNING ARRESTOR REQUIREMENT CALCULATION
PRE/CHKD
: LB/ MK
TITLE
: LIGHTINING CALCULATION
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: Page 9 of 48
A
: 1.0
B
: 0.8
C
: 0.8
D
: 1.0
E
: 0.3
Overall weighing Factors
:AxBxCxDxE : 1.0 x 0.8 x 0.8 x 1.0 x 0.3 : 0.192
Collection Area AC
:
π H2
:
π (29.8) 2 2
: 2788.45 m
6
Probable no.of strikes for the
: Ac x Ng x 10-
structure per year P
: 2788.45 x 3.284 x 10:
Therefore, the overall risk Factor
6
9.157 x 10-3
: P x Overall Weighing Factor : 9.157 x 10-3 x 0.192 3
: 1.75 x 10- which is greater than 10-
Therefore for Cement storage Silo Lightning Protection is essential. KILN NO.3 PREHEATER: Length (L)
: 19.2 M
Width ( W)
: 16 M
Height (H)
: 106 M
Lightning Flashes/Sq.Km / year(Ng) - Rating factor for Wadi
: 3.284
Weighing Factors A
: 1.0
B
: 0.8
C
: 0.8
5
LIGHTNING CALCULATION CLIENT
: ACC – LIMITED
REV/DATE
: 0 /24.06.05
PROJECT
: LIGHTNING ARRESTOR REQUIREMENT CALCULATION
PRE/CHKD
: LB/ MK
TITLE
: LIGHTINING CALCULATION
SHEET
: Page 10 of 48
D
: 1.0
E
: 0.3
Overall weighing Factors
:AxBxCxDxE : 1.0 x 0.8 x 0.8 x 1.0 x 0.3 : 0.192
Collection Area AC
: (L x W) + 2(L x H) + 2(W x H) +
πΗ
2
: (19.2x16)+2(19.2x106)+2(16x106)+π :
2
1290105.505 m 6
Probable no.of strikes for the
: AC x Ng x 10-
structure per year P
: 1290105.505 x 3.284 x 10-
6
: 4.236 Therefore, the overall risk Factor
: P x Overall Weighing Factor : 4.236 x 0.192 : 0.8133
Therefore Lightning Protection is essential for Kiln No.3 Preheater. CEMENT MILL BUILDING : Length (L)
: 34 M
Width ( W)
: 36 M
Height (H)
: 11.5 M
Length (L)
: 22 M
Width ( W)
: 36 M
Height (H)
: 16.5 M
Lightning Flashes/Sq.Km / year(Ng) - Rating factor for Wadi
: 3.284
Weighing Factors A
: 1.0
5
which is greater than 10-
(107.5)
2
LIGHTNING CALCULATION CLIENT
: ACC – LIMITED
REV/DATE
: 0 /24.06.05
PROJECT
: LIGHTNING ARRESTOR REQUIREMENT CALCULATION
PRE/CHKD
: LB/ MK
TITLE
: LIGHTINING CALCULATION
SHEET
: Page 11 of 48
B
: 1.0
C
: 0.8
D
: 1.0
E
: 0.3
Overall weighing Factors
:AxBxCxDxE : 1.0 x 1.0 x 0.8 x 1.0 x 0.3 : 0.24
Collection Area AC
: (L x W) + 2(L x H) + 2(W x H) +
πΗ
2
: (12x36)+2(12x11.5)+(36x11.5)+ (22x36)+2x(22x16.5)+(36x16.5)+π :
4088.86 m
(16.5)
2
6
Probable no.of strikes for the
: AC x Ng x 10-
structure per year P
: 4088.86 x 3.284 x 10-
6
: 1.44 x 10-2 Therefore, the overall risk Factor
: P x Overall Weighing Factor :
1.34 x 10-2 x 0.24
: 3.22 x 10-3 which is greater than 10-
Therefore Lightning Protection is essential for Cement Mill Building. CEMENT MILL 4 & 5 BUILDINGS: Length (L)
: 34 M
Width ( W)
: 36 M
Height (H)
: 16.5 M
Lightning Flashes/Sq.Km / year(Ng) - Rating factor for Wadi
: 3.284
Weighing Factors A
: 1.0
5
2
LIGHTNING CALCULATION CLIENT
: ACC – LIMITED
REV/DATE
: 0 /24.06.05
PROJECT
: LIGHTNING ARRESTOR REQUIREMENT CALCULATION
PRE/CHKD
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: LIGHTINING CALCULATION
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B
: 1.0
C
: 0.8
D
: 1.0
E
: 0.3
Overall weighing Factors
:AxBxCxDxE : 1.0 x 1.0 x 0.8 x 1.0 x 0.3 : 0.24
Collection Area AC
: (L x W) + 2(L x H) + 2(W x H) +
πΗ
: (34x36)+2(34x16.5)+2(36x16.5)+π :
4388.86 m
2
(16.5)
2
6
Probable no.of strikes for the
: AC x Ng x 10-
structure per year P
: 4388.86 x 3.284 x 10-
6
: 1.44 x 10-2 Therefore, the overall risk Factor
: P x Overall Weighing Factor :
1.44 x 10-2 x 0.24
: 3.46 x 10-3 which is greater than 10-
Therefore Lightning Protection is essential for Cement Mill 4 & 5 Buildings .
5
2
LIGHTNING CALCULATION CLIENT
: ACC – LIMITED
REV/DATE
: 0 /24.06.05
PROJECT
: LIGHTNING ARRESTOR REQUIREMENT CALCULATION
PRE/CHKD
: LB/MK
TITLE
: LIGHTINING CALCULATION
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: Page 13 of 48
CEMENT MILL CONTROL ROOM: Length (L)
: 16 M
Width ( W)
: 7.5 M
Height (H)
: 11.5 M
Lightning Flashes/Sq.Km / year(Ng) - Rating factor for Wadi
: 3.284
Weighing Factors A
: 1.0
B
: 1.0
C
: 0.8
D
: 1.0
E
: 0.3
Overall weighing Factors
:AxBxCxDxE : 1.0 x 1.0 x 0.8 x 1.0 x 0.3 : 0.24
Collection Area AC
: (L x W) + 2(L x H) + 2(W x H) +
πΗ
2
: (4x16)+(3.5X6)+(5.25x7.5)+(5.25x13)+ (6X5.25) +(7X5.25)+2X(11.5X3.5)+(11.5X4)+5/4π :
2
552.32 m
6
Probable no.of strikes for the
: AC x Ng x 10-
structure per year P
: 552.32 x 3.284 x 10-
6
: 1.81 x 10-3 Therefore, the overall risk Factor
: P x Overall Weighing Factor :
1.81 x 10-3 x 0.24 5
: 4.3526 x 10-4 which is greater than 10-
Therefore Lightning Protection is essential for Cement Mill Control room .
(11.5)
2
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of 48 PACKING PLANT: Length (L)
: 36.9 M
Width ( W)
: 27 M
Height (H)
: 24.75 M
Lightning Flashes/Sq.Km / year(Ng) - Rating factor for Wadi
: 3.284
Weighing Factors A
: 1.0
B
: 1.0
C
: 0.8
D
: 1.0
E
: 0.3
Overall weighing Factors
:AxBxCxDxE : 1.0 x 1.0 x 0.8 x 1.0 x 0.3 : 0.24
Collection Area AC
: (L x W) + 2(L x H) + 2(W x H) +
πΗ
2
: (23.4x27)+(13.5X15.5)+(24.75x27)+(24.75x11.5)+ (8.5X13.5)+(8.5X15.5)+(36.9X8.5)+ (15.5X8.5)+5/4π :
4890.132 m
(24.75)
2
2
6
Probable no.of strikes for the
: AC x Ng x 10-
structure per year P
: 4890.132 x 3.284 x 10-
6
: 1.6 x 10-2 Therefore, the overall risk Factor
: P x Overall Weighing Factor :
1.6 x 10-2 x 0.24 5
: 3.85 x 10-3 which is greater than 10-
Therefore Lightning Protection is essential for Cement Packing plant.
LIGHTNING CALCULATION CLIENT
: ACC – LIMITED
REV/DATE
: 0 /24.06.05
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: LIGHTNING ARRESTOR REQUIREMENT CALCULATION
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: LB/MK
TITLE
: LIGHTINING CALCULATION
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: Page 15 of 48
CEMENT SILO EXPANSION AND PACKING PLANT: CEMENT SILO: Diameter(D)
: 12 M
Height (H)
: 34.5+2.5=37 M
Lightning Flashes/Sq.Km / year(Ng) - Rating factor for Wadi
: 3.284
Weighing Factors A
: 1.0
B
: 0.8
C
: 0.8
D
: 1.0
E
: 0.3
Overall weighing Factors
:AxBxCxDxE : 1.0 x 0.8 x 0.8 x 1.0 x 0.3 : 0.192
Collection Area AC
:
π H2
:
π (37) 2 2
: 4298.66 m
6
Probable no.of strikes for the
: Ac x Ng x 10-
structure per year P
: 4298.66 x 3.284 x 10:
Therefore, the overall risk Factor
6
1.41 x 10-2
: P x Overall Weighing Factor : 1.41 x 10-2 x 0.192 3
: 2.71 x 10- which is greater than 10-
Therefore for Cement
Silo Lightning Protection is essential.
5
LIGHTNING CALCULATION CLIENT
: ACC – LIMITED
REV/DATE
: 0 /24.06.05
PROJECT
: LIGHTNING ARRESTOR REQUIREMENT CALCULATION
PRE/CHKD
: LB/MK
TITLE
: LIGHTINING CALCULATION
SHEET
: Page 16 of 48
PACKING PLANT: Length (L)
: 14 M
Width ( W)
: 16 M
Height (H)
: 30 M
Lightning Flashes/Sq.Km / year(Ng) - Rating factor for Wadi
: 3.284
Weighing Factors A
: 1.0
B
: 1.0
C
: 0.8
D
: 1.0
E
: 0.3
Overall weighing Factors
:AxBxCxDxE : 1.0 x 1.0 x 0.8 x 1.0 x 0.3 : 0.24
Collection Area AC
: (L x W) + 2(L x H) + 2(W x H) + : (14x16)+2(14X30)+2(16x30)+
:
πΗ
2
π (30)
2
2024 m
6
Probable no.of strikes for the
: AC x Ng x 10-
structure per year P
: 2024 x 3.284 x 10-
6
: 6.646 x 10-3 Therefore, the overall risk Factor
: P x Overall Weighing Factor :
6.646x 10-3 x 0.24
: 1.59 x 10-3 which is greater than 10-
Therefore Lightning Protection is essential for Cement Packing plant.
5
2
LIGHTNING CALCULATION CLIENT
: ACC -WADI
REV/DATE
: 0 /24.06.05
PROJECT
: LIGHTNING ARRESTOR REQUIREMENT CALCULATION
PRE/CHKD
: LB/ MK
TITLE
: LIGHTNING CALCULATION
SHEET
: Page 17 of 48
KILN NO. 1 & 2 PREHEATER: Length (L)
: 11 M
Width ( W)
: 24 M
Height (H)
: 69.36 M
Lightning Flashes/Sq.Km / year(Ng) - Rating factor for Wadi
: 3.284
Weighing Factors A
: 1.0
B
: 0.8
C
: 0.8
D
: 1.0
E
: 0.3
Overall weighing Factors
:AxBxCxDxE : 1.0 x 0.8 x 0.8 x 1.0 x 0.3 : 0.192
Collection Area AC
: (L x W) + 2(L x H) + 2(W x H) +
πΗ
2
: (11x24)+2(11x69.36)+2(24x69.36)+π :
20225.142 m
2
6
Probable no.of strikes for the
: AC x Ng x 10-
structure per year P
: 20225.142 x 3.284 x 10-
6
: 6.64 x 10-2 Therefore, the overall risk Factor
: P x Overall Weighing Factor : 6.64 x 10-2 x 0.192 5
: 1.27 x 10-2 which is greater than 10-
Therefore Lightning Protection is essential for Kiln No.1 & 2 Preheater.
(69.36)
2
LIGHTNING CALCULATION CLIENT
: ACC -WADI
REV/DATE
: 0 /24.06.05
PROJECT
: LIGHTNING ARRESTOR REQUIREMENT CALCULATION
PRE/CHKD
: LB/ MK
TITLE
: LIGHTNING CALCULATION
SHEET
: Page 18 of 48
RAW MILL 4& 5: Length (L)
: 60.1 M
Width ( W)
: 36 M
Height (H)
: 31.35 M
Lightning Flashes/Sq.Km / year(Ng) - Rating factor for Wadi
: 3.284
Weighing Factors A
: 1.0
B
: 1.0
C
: 0.8
D
: 1.0
E
: 0.3
Overall weighing Factors
:AxBxCxDxE : 1.0 x 1.0 x 0.8 x 1.0 x 0.3 : 0.24
Collection Area AC
: (L x W) + 2(L x H) + 2(W x H) +
πΗ
2
: (60.1x36)+2(60.1x31.35)+2(36x31.35)+π :
11275.132 m
2
6
Probable no.of strikes for the
: AC x Ng x 10-
structure per year P
: 11275.132 x 3.284 x 10-
6
: 3.7 x 10-2 Therefore, the overall risk Factor
: P x Overall Weighing Factor : 3.7 x 10-2 x 0.192 : 7.1 x 10-3 which is greater than 10-
Therefore Lightning Protection is essential for Raw mill 4 & 5.
5
(31.35)
2
LIGHTNING CALCULATION CLIENT
: ACC -WADI
REV/DATE
: 0 /24.06.05
PROJECT
: LIGHTNING ARRESTOR REQUIREMENT CALCULATION
PRE/CHKD
: LB/ MK
TITLE
: LIGHTNING CALCULATION
SHEET
: Page 19 of 48
COAL MILL : Length (L)
: 46 M
Width ( W)
: 33 M
Height (H)
: 44 M
Lightning Flashes/Sq.Km / year(Ng) - Rating factor for Wadi
: 3.284
Weighing Factors A
: 1.0
B
: 0.8
C
: 0.8
D
: 1.0
E
: 0.3
Overall weighing Factors
:AxBxCxDxE : 1.0 x 0.8 x 0.8 x 1.0 x 0.3 : 0.192
Collection Area AC
2
: (L x W) + 2(L x H) + 2(W x H) +
πΗ
: (46x33)+2(46x44)+2(33x44)+π
(44)
:
2
14549.04 m
6
Probable no.of strikes for the
: AC x Ng x 10-
structure per year P
: 14549.04 x 3.284 x 10-
6
: 4.77 x 10-2 Therefore, the overall risk Factor
: P x Overall Weighing Factor : 4.77 x 10-2 x 0.192 5
: 9.17 x 10-3 which is greater than 10-
Therefore Lightning Protection is essential for Coal mill .
2
LIGHTNING CALCULATION CLIENT
: ACC -WADI
REV/DATE
: 0 /24.06.05
PROJECT
: LIGHTNING ARRESTOR REQUIREMENT CALCULATION
PRE/CHKD
: LB/ MK
TITLE
: LIGHTNING CALCULATION
SHEET
: Page 20 of 48
POWER PLANT AREA : DG SET BUILDING: Length (L)
: 52 M
Width ( W)
: 20 M
Height (H)
: 15 M
Lightning Flashes/Sq.Km / year(Ng) - Rating factor for Wadi
: 3.284
Weighing Factors A
: 1.0
B
: 0.4
C
: 1.0
D
: 1.0
E
: 0.3
Overall weighing Factors
:AxBxCxDxE : 1.0 x 0.4 x 1.0 x 1.0 x 0.3 : 0.12
Collection Area AC
: (L x W) + 2(L x H) + 2(W x H) + : (52x20)+2(20x15)+π :
(15)
πΗ
2
2
2
2346.5 m
6
Probable no.of strikes for the
: AC x Ng x 10-
structure per year P
: 2346.5 x 3.284 x 10-
6
: 7.705 x 10-3 Therefore, the overall risk Factor
: P x Overall Weighing Factor : 7.705 x 10-3 x 0.12 : 9.247 x 10-4 which is greater than 10-
Therefore Lightning Protection is essential for DG Set Building .
5
LIGHTNING CALCULATION CLIENT
: ACC -WADI
REV/DATE
: 0 /24.06.05
PROJECT
: LIGHTNING ARRESTOR REQUIREMENT CALCULATION
PRE/CHKD
: LB/ MK
TITLE
: LIGHTNING CALCULATION
SHEET
: Page 21 of 48
3 NOS. OF 1 X 25 MW TG BUILDING : Length (L)
: 52.5 M
Width ( W)
: 26.7 M
Height (H)
: 23.56 M
Lightning Flashes/Sq.Km / year(Ng) - Rating factor for Wadi
: 3.284
Weighing Factors A
: 1.0
B
: 0.4
C
: 1.0
D
: 1.0
E
: 0.3
Overall weighing Factors
:AxBxCxDxE : 1.0 x 0.4 x 1.0 x 1.0 x 0.3 : 0.12
Collection Area AC
: (L x W) + 2(L x H) + 2(W x H) +
πΗ
2
: (8x52.5)+(18.7x37.5)+(14.5x12.2)+2(8x14.86) +(52.5x14.86)+2(18.7x23.56)+2(14.5x15.26) +π : There are 3 Nos of 1x25 MW Generator Areas. Therefore Total collection area is
(23.56)
2
5382.67 m
2
: 3x5382.67 m
2
2
: 16146 m
6
Probable no.of strikes for the
: AC x Ng x 10-
structure per year P
: 16146 x 3.284 x 10-
6
: 5.3 x 10-2 Therefore, the overall risk Factor
: P x Overall Weighing Factor : 5.3 x 10-2 x 0.12 5
: 6.36 x 10-3 which is greater than 10Therefore Lightning Protection is essential for TG Building .
LIGHTNING CALCULATION CLIENT
: ACC -WADI
REV/DATE
: 0 /24.06.05
PROJECT
: LIGHTNING ARRESTOR REQUIREMENT CALCULATION
PRE/CHKD
: LB/ MK
TITLE
: LIGHTNING CALCULATION
SHEET
: Page 22 of 48
CHIMNEY -1 Diameter(D)
:4 M
Height (H)
: 113 M
Lightning Flashes/Sq.Km / year(Ng) -Rating factor for Wadi
: 3.284
Weighing Factors A
: 1.0
B
: 0.4
C
: 1.0
D
: 2.0
E
: 0.3
Overall weighing Factors
:AxBxCxDxE : 1.0 x 0.4x 1.0 x 2.0 x 0.3 : 0.24
Collection Area AC
:
π H2
:
π (113) 2 2
: 40094.66 m
6
Probable no.of strikes for the
: Ac x Ng x 10-
structure per year P
: 40094.66 x 3.284 x 10:
Therefore, the overall risk Factor
6
13.16x 10-2
: P x Overall Weighing Factor : 13.16 x 10-2 x 0.24 5
: 3.16 x 10-2 which is greater than 10-
Therefore for Chimney Lightning Protection is essential.
LIGHTNING CALCULATION CLIENT
: ACC -WADI
REV/DATE
: 0 /24.06.05
PROJECT
: LIGHTNING ARRESTOR REQUIREMENT CALCULATION
PRE/CHKD
: LB/ MK
TITLE
: LIGHTNING CALCULATION
SHEET
: Page 23 of 48
CHIMNEY -2 Diameter(D)
:4 M
Height (H)
: 106.8 M
Lightning Flashes/Sq.Km / year(Ng) -Rating factor for Wadi
: 3.284
Weighing Factors A
: 1.0
B
: 0.4
C
: 1.0
D
: 2.0
E
: 0.3
Overall weighing Factors
:AxBxCxDxE : 1.0 x 0.4x 1.0 x 2.0 x 0.3 : 0.24
Collection Area AC
:
π H2
:
π (106.8) 2 2
: 35815.59 m
6
Probable no.of strikes for the
: Ac x Ng x 10-
structure per year P
: 35815.59 x 3.284 x 10:
Therefore, the overall risk Factor
6
11.76x 10-2
: P x Overall Weighing Factor : 11.76 x 10-2 x 0.24 5
: 2.82 x 10-2 which is greater than 10-
Therefore for Chimney Lightning Protection is essential.
LIGHTNING CALCULATION CLIENT
: ACC -WADI
REV/DATE
: 0 /24.06.05
PROJECT
: LIGHTNING ARRESTOR REQUIREMENT CALCULATION
PRE/CHKD
: LB/ MK
TITLE
: LIGHTNING CALCULATION
SHEET
: Page 24 of 48
COLONY AREA WATER TANK (454000 LITRES): Diameter(D)
:13.90 M
Height (H)
: 23.40 M
Lightning Flashes/Sq.Km / year(Ng) -Rating factor for Wadi
: 3.284
Weighing Factors A
: 0.7
B
: 0.4
C
: 0.8
D
: 1.0
E
: 0.3
Overall weighing Factors
:AxBxCxDxE : 0.7 x 0.4x 0.3x 1.0 x 0.3 : 0.0252
Collection Area AC
:
π H2
:
π (23.4) 2 2
: 1719.338 m structure per year P
: 1719.338 x 3.284 x 10-
Probable no.of strikes for the
: Ac x Ng x 10-
6
: Therefore, the overall risk Factor
6
5.67x 10-3
: P x Overall Weighing Factor : 5.67 x 10-3 x 0.0252 : 1.428 x 10-4 which is greater than 10-
Therefore for Water tank Lightning Protection is essential.
5
LIGHTNING CALCULATION CLIENT
: ACC -WADI
REV/DATE
: 0 /24.06.05
PROJECT
: LIGHTNING ARRESTOR REQUIREMENT CALCULATION
PRE/CHKD
: LB/ MK
TITLE
: LIGHTNING CALCULATION
SHEET
: Page 25 of 48
WATER TANK (227000 LITRES) 2 Nos: Diameter(D)
:9.4 M
Height (H)
: 24.55 M
Lightning Flashes/Sq.Km / year(Ng) -Rating factor for Wadi
: 3.284
Weighing Factors A
: 0.7
B
: 0.4
C
: 0.8
D
: 1.0
E
: 0.3
Overall weighing Factors
:AxBxCxDxE : 0.7 x 0.4x 0.3x 1.0 x 0.3 : 0.0252
Collection Area AC
:
π H2
:
π (24.55) 2 2
: 1892.485 m
6
Probable no.of strikes for the
: Ac x Ng x 10-
structure per year P
: 1892.485 x 3.284 x 10:
Therefore, the overall risk Factor
6
6.21x 10-3
: P x Overall Weighing Factor : 6.21 x 10-3 x 0.0252 : 1.568 x 10-4 which is greater than 10-
Therefore for Water tank Lightning Protection is essential.
5
LIGHTNING CALCULATION CLIENT
: ACC -WADI
REV/DATE
: 0 /24.06.05
PROJECT
: LIGHTNING ARRESTOR REQUIREMENT CALCULATION
PRE/CHKD
: LB/ MK
TITLE
: LIGHTNING CALCULATION
SHEET
: Page 26 of 48
KAGINA GUEST HOUSE: Length (L)
: 40 M
Width ( W)
: 15 M
Height (H)
: 10 M
Lightning Flashes/Sq.Km / year(Ng) - Rating factor for Wadi
: 3.284
Weighing Factors A
: 1.2
B
: 0.4
C
: 1.7
D
: 0.4
E
: 0.3
Overall weighing Factors
:AxBxCxDxE : 1.2 x 0.4 x 1.7 x 0.4 x 0.3 : 0.0979
Collection Area AC
2
: (L x W) + 2(L x H) + 2(W x H) +
πΗ
: (40x15)+2(40x10)+2(15x10) +π
(10)
:
2
2014 m
6
Probable no.of strikes for the
: AC x Ng x 10-
structure per year P
: 2014 x 3.284 x 10-
6
: 6.613 x 10-3 Therefore, the overall risk Factor
: P x Overall Weighing Factor : 6.613 x 10-3 x 0.0979 5
: 6.47 x 10-4 which is greater than 10Therefore Lightning Protection is essential for Kagina Guest House .
2
LIGHTNING CALCULATION CLIENT
: ACC -WADI
REV/DATE
: 0 /24.06.05
PROJECT
: LIGHTNING ARRESTOR REQUIREMENT CALCULATION
PRE/CHKD
: LB/ MK
TITLE
: LIGHTNING CALCULATION
SHEET
: Page 27 of 48
MANAGEMENT TRAINEE HOSTEL: Length (L)
: 17 M
Width ( W)
:
Height (H)
: 10 M
Lightning Flashes/Sq.Km / year(Ng) - Rating factor for Wadi
: 3.284
M
Weighing Factors A
: 1.2
B
: 0.4
C
: 1.7
D
: 0.4
E
: 0.3
Overall weighing Factors
:AxBxCxDxE : 1.2 x 0.4 x 1.7 x 0.4 x 0.3 : 0.0979
Collection Area AC
2
: (L x W) + 2(L x H) + 2(W x H) +
πΗ
: (40x15)+2(40x10)+2(15x10) +π
(10)
:
2
2014 m
6
Probable no.of strikes for the
: AC x Ng x 10-
structure per year P
: 2014 x 3.284 x 10-
6
: 6.613 x 10-3 Therefore, the overall risk Factor
: P x Overall Weighing Factor : 6.613 x 10-3 x 0.0979 5
: 6.47 x 10-4 which is greater than 10Therefore Lightning Protection is essential for Management Trainee hostel .
2
LIGHTNING CALCULATION CLIENT
: ACC -WADI
REV/DATE
: 0 /24.06.05
PROJECT
: LIGHTNING ARRESTOR REQUIREMENT CALCULATION
PRE/CHKD
: LB/ MK
TITLE
: LIGHTNING CALCULATION
SHEET
: Page 28 of 48
V. P BUNGALOW: Length (L)
: 22.76 M
Width ( W)
: 15.25M
Height (H)
: 6.80 M
Lightning Flashes/Sq.Km / year(Ng) - Rating factor for Wadi
: 3.284
Weighing Factors A
: 1.2
B
: 0.4
C
: 1.7
D
: 0.4
E
: 0.3
Overall weighing Factors
:AxBxCxDxE : 1.2 x 0.4 x 1.7 x 0.4 x 0.3 : 0.0979
Collection Area AC
: (L x W) + 2(L x H) + 2(W x H) +
πΗ
2
: (10x22.76)+(5.58x14.11)+(10x4.1)+2(8.65X4.1) +(5.58X6.8)+2(14.11X6.8)+(15.25X6.8)+π :
2
861.53 m
6
Probable no.of strikes for the
: AC x Ng x 10-
structure per year P
: 861.53 x 3.284 x 10-
6
: 2.829 x 10-3 Therefore, the overall risk Factor
: P x Overall Weighing Factor : 2.829 x 10-3 x 0.0979 5
: 2.76 x 10-4 which is greater than 10Therefore Lightning Protection is essential for Vice president Bungalow .
(6.8)
2
LIGHTNING CALCULATION CLIENT
: ACC -WADI
REV/DATE
: 0 /24.06.05
PROJECT
: LIGHTNING ARRESTOR REQUIREMENT CALCULATION
PRE/CHKD
: LB/ MK
TITLE
: LIGHTNING CALCULATION
SHEET
: Page 29 of 48
SPORTS CLUB: Length (L)
: 55 M
Width ( W)
: 20M
Height (H)
: 18 M
Lightning Flashes/Sq.Km / year(Ng) - Rating factor for Wadi
: 3.284
Weighing Factors A
: 1.3
B
: 0.4
C
: 1.7
D
: 1.0
E
: 0.3
Overall weighing Factors
:AxBxCxDxE : 1.3 x 0.4 x 1.7 x 1.0 x 0.3 : 0.2652
Collection Area AC
: (L x W) + 2(L x H) + 2(W x H) + : (55x20)+2(55x18)+2(20x18)+ :
πΗ
2
π (18)
2
4817.36 6
Probable no.of strikes for the
: AC x Ng x 10-
structure per year P
: 4817.36 x 3.284 x 10-
6
: 1.58 x 10-4 Therefore, the overall risk Factor
: P x Overall Weighing Factor : 1.58 x 10-4 x 0.2652 : 4.1955 x 10-3 which is greater than 10-
Therefore Lightning Protection is essential for Sports club building .
5
LIGHTNING CALCULATION CLIENT
: ACC -WADI
REV/DATE
: 0 /24.06.05
PROJECT
: LIGHTNING ARRESTOR REQUIREMENT CALCULATION
PRE/CHKD
: LB/ MK
TITLE
: LIGHTNING CALCULATION
SHEET
: Page 30 of 48
QUARY CRUSHER: Length (L)
: 24 M
Width ( W)
: 12M
Height (H)
: 15 M
Lightning Flashes/Sq.Km / year(Ng) - Rating factor for Wadi
: 3.284
Weighing Factors A
: 1.0
B
: 0.8
C
: 0.8
D
: 1.0
E
: 0.3
Overall weighing Factors
:AxBxCxDxE : 1.0 x 0.8 x 0.8 x 1.0 x 0.3 : 0.192
Collection Area AC
πΗ
: (24x12)+2(24x15)+2(12x15)+π
(15)
:
2
2074.9 m
6
Probable no.of strikes for the
: AC x Ng x 10-
structure per year P
: 2074.9 x 3.284 x 10-
6
: 0.6812 x 10-2 Therefore, the overall risk Factor
2
: (L x W) + 2(L x H) + 2(W x H) +
: P x Overall Weighing Factor : 0.6812 x 10-2 x 0.192 : 1.3 x 10-4 which is greater than 10-
Therefore Lightning Protection is essential for Quary crusher .
5
2
LIGHTNING CALCULATION CLIENT
: ACC -WADI
REV/DATE
: 0 /24.06.05
PROJECT
: LIGHTNING ARRESTOR REQUIREMENT CALCULATION
PRE/CHKD
: LB/ MK
TITLE
: LIGHTNING CALCULATION
SHEET
: Page 31 of 48
WATER TANK IN RIVER PUMP AREA 3 Nos: Diameter(D)
:4 M
Height (H)
: 12 M
Lightning Flashes/Sq.Km / year(Ng) -Rating factor for Wadi
: 3.284
Weighing Factors A
: 0.7
B
: 0.4
C
: 0.8
D
: 1.0
E
: 0.3
Overall weighing Factors
:AxBxCxDxE : 0.7 x 0.4x 0.3x 1.0 x 0.3 : 0.0252
Collection Area AC
:
π H2
:
π (12) 2
: 452.16 m
2
6
Probable no.of strikes for the
: Ac x Ng x 10-
structure per year P
: 452.16 x 3.284 x 10:
Therefore, the overall risk Factor
6
1.48x 10-3
: P x Overall Weighing Factor : 1.48 x 10-3 x 0.0252 : 3.7 x 10-4 which is greater than 10-
Therefore for Water tank Lightning Protection is essential.
5
LIGHTNING CALCULATION CLIENT
: ACC -WADI
REV/DATE
: 0 /24.06.05
PROJECT
: LIGHTNING ARRESTOR REQUIREMENT CALCULATION
PRE/CHKD
: LB/ MK
TITLE
: LIGHTNING CALCULATION
SHEET
: Page 32 of 48
5.0 Resistance of Pipe Electrode (Ref. 9.2.2 of IS: 3043-1987) Re = 100 x ρ 2xπxl Where
loge 4 x l d
l = length of the rod or pipe = 300 cm. d = diameter of the rod or pipe = 3.8 cm. ρ = resistivity of soil = 312 Ω -m assumed uniform. Re = 100 x 312 2 x π x 300
loge 4 x 300 3.8
= 16.55 loge 315.789 = 41.36 Ω. Resistance of the Earth Strip 50 x 6 G.I Flat Old Wadi plant 5.1.1 Bulk loading silo Rs
= 100
ρ Log e
2π L
2L
2
wt
L=Estimated Length Strip
: 12500 cm
Width of the Strip (t)
: 50 x 6 mm
Depth of the Buried Strip (W)
:
Rs
= 100 x 312
Log
e
2 x 12500
2x3.14x12500
60 cm 2
=
2.38 Ω
60x5
There are 3 Nos of earth pits are used, therefore Re
Rt
=
=
Re /3
Re
x Rs
Re + Rs
=
=
41.36 / 3
13.78 X 2.38
= 13.78 Ω
=
2.03 Ω
13.78+2.38
Thus the Total resistance is less than 3 ohms . 50x6 G.I Flat strip is selected for vertical down conductor and horizondal conductor.
earth
LIGHTNING CALCULATION CLIENT
: ACC -WADI
REV/DATE
: 0 /24.06.05
PROJECT
: LIGHTNING ARRESTOR REQUIREMENT CALCULATION
PRE/CHKD
: LB/ MK
TITLE
: LIGHTNING CALCULATION
SHEET
: Page 33 of 48
5.1.2
Cement storage silo Rs
= 100
ρ Log e
2π L
2L
2
wt
L=Estimated Length Strip
: 14640 cm
Width of the Buried Strip (t)
: 50 x 6 mm
Depth of the Buried Strip (W)
:
Rs
= 100 x 312
Log
e
2 x 14640
2x3.14x14640
60 cm 2
=
2.0 Ω
60x5
There are 2 Nos of earth pits are used, therefore Re
=
Rt
=
Re /2 Re
=
x Rs
=
Re + Rs
41.36 / 2 20.68 X 2
= 20.68 Ω =
1.8 Ω
20.68+2.
Thus the Total resistance is less than 3 ohms . 50x6 G.I Flat strip is selected for vertical down conductor and horizondal conductor.
5.1.3
Kiln No:3 Preheater Rs
= 100
ρ Log e
2π L
2L
2
wt
L=Estimated Length Strip
: 30160 cm
Width of the Buried Strip (t)
: 50 x 6 mm
Depth of the Buried Strip (W)
:
Rs
= 100 x 312
Log
e
2 x 30160
2x3.14x30160
60 cm 2
=
60x5
There are 2 Nos of earth pits are used, therefore Re
=
Re /2
=
41.36 / 2
= 20.68 Ω
1.1172 Ω
earth
LIGHTNING CALCULATION CLIENT
: ACC -WADI
REV/DATE
: 0 /24.06.05
PROJECT
: LIGHTNING ARRESTOR REQUIREMENT CALCULATION
PRE/CHKD
: LB/ MK
TITLE
: LIGHTNING CALCULATION
SHEET
: Page 34 of 48
Rt
=
Re
x Rs
=
Re + Rs
20.68 X 1.1172
=
1.054 Ω
20.68+1.1172.
Thus the Total resistance is less than 3 ohms . 50x6 G.I Flat strip is selected for vertical down conductor and horizondal conductor. 5.1.4
earth
Cement Mill Building Rs
= 100
ρ Log e
2L
2π L
2
wt
L=Estimated Length Strip
: 20405.6 cm
Width of the Buried Strip (t)
: 50 x 6 mm
Depth of the Buried Strip (W)
:
Rs
= 100 x 312
Log
e
60 cm
2 x 20405.6
2x3.14x20405.6
2
=
1.568 Ω
60x5
There are 2 Nos of earth pits are used, therefore Re Rt
= =
Re /2 Re
x Rs
Re + Rs
= =
41.36 / 2 20.68 X 1.568
= 20.68 Ω =
1.4469 Ω
20.68+1.568.
Thus the Total resistance is less than 3 ohms . 50x6 G.I Flat strip is selected for vertical down conductor and horizondal conductor.
earth
LIGHTNING CALCULATION CLIENT
: ACC -WADI
REV/DATE
: 0 /24.06.05
PROJECT
: LIGHTNING ARRESTOR REQUIREMENT CALCULATION
PRE/CHKD
: LB/ MK
TITLE
: LIGHTNING CALCULATION
SHEET
: Page 35 of 48
5.1.5
Cement Mill Building 4 & 5 Rs
= 100
ρ Log e
2L
2π L
2
wt
L=Estimated Length Strip
: 20405.6 cm
Width of the Buried Strip (t)
: 50 x 6 mm
Depth of the Buried Strip (W)
:
Rs
= 100 x 312
Log
e
60 cm
2 x 20405.6
2x3.14x20405.6
2
=
1.568 Ω
60x5
There are 2 Nos of earth pits are used, therefore Re Rt
= =
Re /2 Re
x Rs
= 20.68 Ω
=
41.36 / 2
=
20.68X 1.568
Re + Rs
=
1.4469 Ω
20.68+1.568.
Thus the Total resistance is less than 3 ohms . 50x6 G.I Flat strip is selected for vertical down conductor and horizondal conductor. 5.1.6
Cement Mill Control Room Rs
= 100
ρ Log e
2L
2π L
2
wt
L=Estimated Length Strip
: 10394.8 cm
Width of the Buried Strip (t)
: 50 x 6 mm
Depth of the Buried Strip (W)
:
Rs
= 100 x 312
Log
2x3.14x10394.8
e
60 cm
2 x 10394.8 60x5
Only one earth pit is used, therefore Re
=
Re /1 =
41.36 / 1
= 41.36 Ω
2
=
2.799 Ω
earth
LIGHTNING CALCULATION CLIENT
: ACC -WADI
REV/DATE
: 0 /24.06.05
PROJECT
: LIGHTNING ARRESTOR REQUIREMENT CALCULATION
PRE/CHKD
: LB/ MK
TITLE
: LIGHTNING CALCULATION
SHEET
: Page 36 of 48
Rt
=
Re
x Rs
=
Re + Rs
41.36 X 2.799
=
2.6 Ω
41.36+2.799.
Thus the Total resistance is less than 3 ohms . 50x6 G.I Flat strip is selected for vertical down conductor and horizondal conductor. 5.1.7
earth
Packing Plant Rs
= 100
ρ Log e
2π L
2L
2
wt
L=Estimated Length Strip
: 17730 cm
Width of the Buried Strip (t)
: 50 x 6 mm
Depth of the Buried Strip (W)
:
Rs
= 100 x 312
Log
e
2 x 17730
2x3.14x17730
60 cm 2
=
1.77 Ω
60x5
There are 2 Nos of earth pits are used, therefore Re
Rt
=
=
Re /2 =
Re
x Rs
41.36 / 2
=
Re + Rs
= 20.68 Ω
20.68 X 1.77
=
1.68 Ω
20.68+1.77.
Thus the Total resistance is less than 3 ohms . 50x6 G.I Flat strip is selected for vertical down conductor and horizondal conductor. 5.1.8
Cement silo Expansion Rs
= 100
ρ Log e
2π L
2L
2
wt
L=Estimated Length Strip
: 32033 cm
Width of the Buried Strip (t)
: 50 x 6 mm
Depth of the Buried Strip (W)
:
60 cm
earth
LIGHTNING CALCULATION CLIENT
: ACC -WADI
REV/DATE
: 0 /24.06.05
PROJECT
: LIGHTNING ARRESTOR REQUIREMENT CALCULATION
PRE/CHKD
: LB/ MK
TITLE
: LIGHTNING CALCULATION
SHEET
: Page 37 of 48
Rs
= 100 x 312
Log
e
2 x 32033
2x3.14x32033
2
=
1.07 Ω
60x5
There are 2 Nos of earth pits are used, therefore Re
Rt
=
=
Re /2 =
Re
= 20.68 Ω
41.36 / 2
x Rs
=
Re + Rs
20.68 X 1.07
=
1.0 Ω
20.68+1.07.
Thus the Total resistance is less than 3 ohms . 50x6 G.I Flat strip is selected for vertical down conductor and horizondal conductor. 5.1.9
earth
Kiln No:1& 2 Preheater Rs
= 100
ρ Log e
2π L
2L
2
wt
L=Estimated Length Strip
: 25672 cm
Width of the Buried Strip (t)
: 50 x 6 mm
Depth of the Buried Strip (W)
:
Rs
= 100 x 312
Log
e
2 x 25672
2x3.14x25672
60 cm 2
=
1.285 Ω
60x5
Only one earth pit is used, therefore Re
Rt
=
=
Re /1 =
Re
x Rs
Re + Rs
41.36 / 1
=
= 41.36 Ω
41.36X1.285
=
1.240 Ω
41.36+1.285.
Thus the Total resistance is less than 3 ohms . 50x6 G.I Flat strip is selected for vertical down conductor and horizondal conductor.
earth
LIGHTNING CALCULATION CLIENT
: ACC -WADI
REV/DATE
: 0 /24.06.05
PROJECT
: LIGHTNING ARRESTOR REQUIREMENT CALCULATION
PRE/CHKD
: LB/ MK
TITLE
: LIGHTNING CALCULATION
SHEET
: Page 38 of 48
5.1.10
Raw Mill 4 & 5 Rs
= 100
ρ Log e
2π L
2L
2
wt
L=Estimated Length Strip
: 56730cm
Width of the Buried Strip (t)
: 50 x 6 mm
Depth of the Buried Strip (W)
:
Rs
= 100 x 312
Log
e
60 cm
2 x 56730
2x3.14x56730
2
=
0.64 Ω
60x5
There are 2 Nos of earth pits are used, therefore Re
Rt
=
=
Re /2 =
Re
41.36 / 2= 20.68 Ω
x Rs
=
Re + Rs
20.68X0.64
=
0.62 Ω
20.68+0.64.
Thus the Total resistance is less than 3 ohms . 50x6 G.I Flat strip is selected for vertical down conductor and horizondal conductor. 5.1.11
Coal Mill Rs
= 100
ρ Log e
2π L
2L
2
wt
L=Estimated Length Strip
: 52000cm
Width of the Buried Strip (t)
: 50 x 6 mm
Depth of the Buried Strip (W)
:
Rs
= 100 x 312
Log
e
2 x 52000
2x3.14x52000
60 cm 2
=
60x5
There are 2 Nos of earth pits are used, therefore Re
=
Re /2 =
41.36 / 2= 20.68 Ω
0.64 Ω
earth
LIGHTNING CALCULATION CLIENT
: ACC -WADI
REV/DATE
: 0 /24.06.05
PROJECT
: LIGHTNING ARRESTOR REQUIREMENT CALCULATION
PRE/CHKD
: LB/ MK
TITLE
: LIGHTNING CALCULATION
SHEET
: Page 39 of 48
Rt
=
Re
x Rs
=
Re + Rs
20.68X0.64
=
0.62 Ω
20.68+0.64.
Thus the Total resistance is less than 3 ohms . 50x6 G.I Flat strip is selected for vertical down conductor and horizondal conductor.
earth
5.1 Power plant 5.2.1 DG Set Rs
= 100
ρ Log e
2π L
2L
2
wt
L=Estimated Length Strip
: 63800cm
Width of the Buried Strip (t)
: 50 x 6 mm
Depth of the Buried Strip (W)
:
Rs
= 100 x 312
Log
e
2 x 63800
2x3.14x63800
60 cm 2
=
0.578 Ω
60x5
There are 3 Nos of earth pits are used, therefore Re
Rt
=
=
Re /3 =
Re
x Rs
41.36 / 3= 13.78 Ω
=
Re + Rs
13.78X0.578
=
0.55 Ω
13.78+0.578
Thus the Total resistance is less than 3 ohms . 50x6 G.I Flat strip is selected for vertical down conductor and horizondal conductor. 5.2.2 T.G CPP Building Rs
= 100
ρ Log e
2π L
2L
2
wt
earth
LIGHTNING CALCULATION CLIENT
: ACC -WADI
REV/DATE
: 0 /24.06.05
PROJECT
: LIGHTNING ARRESTOR REQUIREMENT CALCULATION
PRE/CHKD
: LB/ MK
TITLE
: LIGHTNING CALCULATION
SHEET
: Page 40 of 48
L=Estimated Length Strip
: 81802.2cm
Width of the Buried Strip (t)
: 50 x 6 mm
Depth of the Buried Strip (W)
:
Rs
= 100 x 312
Log
e
60 cm
2 x 81802.2
2x3.14x81802.2
2
0.588 Ω
=
60x5
There are 3 Nos of earth pits are used, therefore Re
Rt
=
=
Re /4 =
Re
41.36 / 4= 10.34 Ω
x Rs
=
Re + Rs
10.34X0.588
=
0.5532 Ω
10.34+0.588
Thus the Total resistance is less than 3 ohms . 50x6 G.I Flat strip is selected for vertical down conductor and horizondal conductor.
5.2.3 Chimney-1 Rs
= 100
ρ Log e
2π L
2L
2
wt
L=Estimated Length Strip
: 23659cm
Width of the Buried Strip (t)
: 50 x 6 mm
Depth of the Buried Strip (W)
:
Rs
= 100 x 312
Log
e
2 x 23659
2x3.14x23659
60 cm 2
=
60x5
There are 2 Nos of earth pits are used, therefore Re
=
Re /2 =
41.36 / 2= 20.68 Ω
1.379 Ω
earth
LIGHTNING CALCULATION CLIENT
: ACC -WADI
REV/DATE
: 0 /24.06.05
PROJECT
: LIGHTNING ARRESTOR REQUIREMENT CALCULATION
PRE/CHKD
: LB/ MK
TITLE
: LIGHTNING CALCULATION
SHEET
: Page 41 of 48
Rt
=
Re
x Rs
=
Re + Rs
20.68X1.379
=
1.285 Ω
20.68+1.379.
Thus the Total resistance is less than 3 ohms . 50x6 G.I Flat strip is selected for vertical down conductor and horizondal conductor.
earth
Chimney-2 Rs
= 100
ρ Log e
2π L
2L
2
wt
L=Estimated Length Strip
: 24899cm
Width of the Buried Strip (t)
: 50 x 6 mm
Depth of the Buried Strip (W)
:
Rs
= 100 x 312
Log
e
2 x 24899
2x3.14x24899
60 cm 2
=
1.379 Ω
60x5
There are 2 Nos of earth pits are used, therefore
Re
Rt
=
=
Re
Re /2 =
x Rs
Re + Rs
=
41.36 / 2= 20.68 Ω
20.68X1.379
=
1.285 Ω
20.68+1.379.
Thus the Total resistance is less than 3 ohms . 50x6 G.I Flat strip is selected for vertical down conductor and horizondal conductor.
earth
LIGHTNING CALCULATION CLIENT
: ACC -WADI
REV/DATE
: 0 /24.06.05
PROJECT
: LIGHTNING ARRESTOR REQUIREMENT CALCULATION
PRE/CHKD
: LB/ MK
TITLE
: LIGHTNING CALCULATION
SHEET
: Page 42 of 48
5.3
Colony
5.3.1 Water Tank (454000 Litres) Rs
= 100
ρ Log e
2L
2π L
2
wt
L=Estimated Length Strip
: 15875.2cm
Width of the Buried Strip (t)
: 50 x 6 mm
Depth of the Buried Strip (W)
:
Rs
= 100 x 312
Log
e
60 cm
2 x 15875.2
2x3.14x15875.2
2
=
1.94 Ω
60x5
There are 2 Nos of earth pits are used, therefore Re Rt
=
=
Re
Re /2 =
x Rs
=
Re + Rs
41.36 / 2= 20.68 Ω 20.68X1.94
=
1.764 Ω
20.68+1.94.
Thus the Total resistance is less than 3 ohms . 50x6 G.I Flat strip is selected for vertical down conductor and horizondal conductor.
Water Tank (227000 Litres) Rs
= 100
ρ Log e
2π L
2L
2
wt
L=Estimated Length Strip
: 13329.2cm
Width of the Buried Strip (t)
: 50 x 6 mm
Depth of the Buried Strip (W)
:
60 cm
earth
LIGHTNING CALCULATION CLIENT
: ACC -WADI
REV/DATE
: 0 /24.06.05
PROJECT
: LIGHTNING ARRESTOR REQUIREMENT CALCULATION
PRE/CHKD
: LB/ MK
TITLE
: LIGHTNING CALCULATION
SHEET
: Page 43 of 48
Rs
= 100 x 312
Log
e
2 x 13329.2
2x3.14x13329.2
2
2.26 Ω
=
60x5
There are 2 Nos of earth pits are used, therefore Re
Rt
=
=
Re
Re /2 =
x Rs
=
Re + Rs
41.36 / 2= 20.68 Ω
20.36X2.26
=
2.0 Ω
20.36+2.26.
Thus the Total resistance is less than 3 ohms . 50x6 G.I Flat strip is selected for vertical down conductor and horizondal conductor.
Kagina Guest house Rs
= 100
ρ Log e
2π L
2L
2
wt
L=Estimated Length Strip
: 22100cm
Width of the Buried Strip (t)
: 50 x 6 mm
Depth of the Buried Strip (W)
:
Rs
= 100 x 312
Log
e
60 cm
2 x 22100
2x3.14x22100
2
=
1.46 Ω
60x5
There are 2 Nos of earth pits are used, therefore
Re
Rt
=
=
Re
Re /2 =
x Rs
Re + Rs
=
41.36 / 2= 20.68 Ω
20.36X1.46 20.36+1.46.
=
1.35 Ω
earth
LIGHTNING CALCULATION CLIENT
: ACC -WADI
REV/DATE
: 0 /24.06.05
PROJECT
: LIGHTNING ARRESTOR REQUIREMENT CALCULATION
PRE/CHKD
: LB/ MK
TITLE
: LIGHTNING CALCULATION
SHEET
: Page 44 of 48
Thus the Total resistance is less than 3 ohms . 50x6 G.I Flat strip is selected for vertical down conductor and horizondal conductor.
earth
V.P Bungalow Rs
= 100
ρ Log e
2π L
2L
2
wt
L=Estimated Length Strip
: 14194m
Width of the Buried Strip (t)
: 50 x 6 mm
Depth of the Buried Strip (W)
:
Rs
= 100 x 312
Log
e
60 cm
2 x 14194
2x3.14x14194
2
=
2.14 Ω
60x5
There are 2 Nos of earth pits are used, therefore
Re
Rt
=
=
Re
Re /2 =
x Rs
Re + Rs
=
41.36 / 2= 20.68 Ω
20.36X2.14
=
1.925 Ω
20.36+2.14.
Thus the Total resistance is less than 3 ohms . 50x6 G.I Flat strip is selected for vertical down conductor and horizondal conductor.
earth
LIGHTNING CALCULATION CLIENT
: ACC -WADI
REV/DATE
: 0 /24.06.05
PROJECT
: LIGHTNING ARRESTOR REQUIREMENT CALCULATION
PRE/CHKD
: LB/ MK
TITLE
: LIGHTNING CALCULATION
SHEET
: Page 45 of 48
Sports Club Rs
= 100
ρ Log e
2π L
2L
2
wt
L=Estimated Length Strip
: 33200m
Width of the Buried Strip (t)
: 50 x 6 mm
Depth of the Buried Strip (W)
:
Rs
= 100 x 312
Log
e
2 x 33200
2x3.14x33200
60 cm 2
=
1.027 Ω
60x5
There are 2 Nos of earth pits are used, therefore
Re Rt
=
=
Re
Re /2 =
x Rs
Re + Rs
=
41.36 / 2= 20.68 Ω 20.36X1.027
=
0.97 Ω
20.36+1.027.
Thus the Total resistance is less than 3 ohms . 50x6 G.I Flat strip is selected for vertical down conductor and horizondal conductor.
earth
LIGHTNING CALCULATION CLIENT
: ACC -WADI
REV/DATE
: 0 /24.06.05
PROJECT
: LIGHTNING ARRESTOR REQUIREMENT CALCULATION
PRE/CHKD
: LB/ MK
TITLE
: LIGHTNING CALCULATION
SHEET
: Page 46 of 48
6.0
RESULTS
a) 38 mm ID,3 M long pipe suggested for earth pit refer drg. No. E-ECBA565-LTNG-001(Sheet 2 of 4). b) 50 x 6 G.I flat strip suggested for down conductors and burried conductor. c) The No.of Lightning conductors and earth pits required are as shown in the drawing. d) The Lightning conductor shall be placed at the topmost height of every Building. e) The Location of Earthpits shall be fixed as per the site conditions. f) The Earthing Resistance shall be maintained below 3 ohms. g) The down conductors shall be insulated from the metal structures inorder to reduce the leakage current. h) All the down conductors shall have a test Link arrangement between the arrestor and Earthpit. Old Wadi plant Area: Location of Lightning Conductor
the
No.of Lightnin g Conduct or. 2
No.of Earth Pits
2
3
One Arrestor at each silo.
Packing plant
1
2
Shall be placed at the topmost structure.
Cement storage silo
2
2
Arrestor Shall be placed at the topmost structure.
Cement mill building 4&5
2
2
Arrestor Shall be placed at topmost structure.
Raw mill 4&5
2
2
Arrestor Shall be placed at the topmost structure.
Coal mill
2
2
Arrestor Shall be placed at the topmost
KilnNo-1&2 Preheater Bulk loading cement silo
Remarks
2
LIGHTNING CALCULATION CLIENT
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: LIGHTNING ARRESTOR REQUIREMENT CALCULATION
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TITLE
: LIGHTNING CALCULATION
SHEET
: Page 47 of 48
structure. Kiln No.3 preheater
2
2
Arrestor Shall be placed at the topmost structure.
Cement expansion
4
4
4 silo in a line.In each silo one arrestor shall be placed.
2
2
Arrestor Shall be placed at the topmost structure.
silo
Cement mill building
Colony Area Note: The Horizotal Air terminations to be Placed as marked in the drawing for Water Tanks and Gust houses. Description
No.of Earth Pit 2
Remarks
Water Tank (2 Nos)
No.of Arrestor 2
Kagina guest house
1
2
One Arrestor is already existing No need to provide additional arrestor.
Management hostel
1
2
One Arrestor is already existing No need to provide.
V.P Bungalow
1
2
One Arrester is already existing No need to provide.
Sports club
2
2
One Arrestor is placed, one more should be placed.
trainee
One Arrestor is placed in each Tank. So no need to provide additional arrestor.
LIGHTNING CALCULATION CLIENT
: ACC -WADI
REV/DATE
: 0 /24.06.05
PROJECT
: LIGHTNING ARRESTOR REQUIREMENT CALCULATION
PRE/CHKD
: LB/ MK
TITLE
: LIGHTNING CALCULATION
SHEET
: Page 48 of 48
Power plant Area Note: The Horizotal Air terminations to be Placed as marked in the drawing for D.G set building & T.G building. As the Chimneys are provided with the 2 nos of 25x3 GI Flat as down conductor, the same shall be retained as it is and the required earth value of less than 3 ohms should be confirmed. Description
No.of Earth Pit 3
Remarks
D.G Set
No.of Arrestor 2
T.G CPP building
10
4
7 Arrestor is already existing remaining 3 should be placed as per drawing.
Chimney 2Nos
2
4
One Arrestor is existing in each chimney. No need to provde.
Two Arrestor is existing. No need to provide.
River pump Area a)
There are three Tank in this area ,in each Tank one Arrester shall be placed.
c) In quary crusher area one Arrestor and Two nos. of earth pits shall be placed as marked in the drawing.
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