BASICS OF LIGHTNING PROTECTION

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Nathaniel Dalton
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1 sabo BASICS OF LIGHTNING PROTECTION Lightning is an important phenomenon, which one cannot resist without danger, but which is easily led if one lets it have its way. It possesses millions of volts, capable of shattering insulating obstacles, but flows meekly through small-diameter conductors. Since it is curious during its descent to explore neighboring metal structures and conductors, where, rightly or wrongly, it hopes to find an easier outlet, it is wiser to pave its way with appropriate interconnections than to bar its way with obstacles that are ineffective. The essential idea behind every Lightning Protection System is to avoid situations in which these forces get diverted to vulnerable points of a building / installation. In other words the Lightning Protection Systems should be able to provide the favourable path for the lightning to go to the ground thereby preventing it to strike any unwanted area. Every year lightning causes millions of Rupees worth of damages to structures and electronics as a result of over voltages and thermal damages. The awesome natural phenomenon of lightning, which strikes the earth an estimated 6,000 times per minute, is an ever present and unpredictable enemy. It is a danger to humanity and a danger to all the equipments and structures. THE EFFECTS OF LIGHTNING: The main effects of Lightning are as follows: i. Thermal effects: These effects are linked to the quantity of charges involved when lightning Strikes. For materials with high resistivity, they cause various melting points at the places of impact. On poorly materials, a large amount of energy is released in the form of heat. The moisture they contain causes sudden overpressure that may result in explosion. ii. Effect due to arching: The resistivity of the soil makes earthing resistant and therefore unable to prevent a sudden rise in the facility s potential when lightning current passes through it. This creates differences in potential between the various metal parts. iii. Electrodynamics effects: These effects are produced if part of the path along which the lightning current travels is within the magnetic field of another part. This may produce repulsion and attraction forces when lightning travels through conductors situated close to each other. iv. Induction effects: Induction effects are often the biggest challenge to protection systems. When lightning approaches a site, it creates a magnetic flux that produces high, and sometimes destructive, induced voltages. v. Indirect effects: Offset potential or pace voltage. Dispersion of lightning currents in the soil depends on the nature of the terrain. A heterogeneous soil may create dangerous differences of potential between two neighboring points.

2 sabo Introduction to Lightning Protection Technology Lightning Conductor s function is to divert to itself a lightning discharge, which might otherwise strike a vulnerable part of the structure/facility to be protected. Before proceeding with the detailed design of a lightning protective system, the following essential steps should be taken: i. Decide whether or not the structure needs protection and, it, so, what are the special requirements. ii. Ensure a close liaison between the architect, the builder, the lightning protection system engineer so that the appropriate design is made which provides the complete protection cover to the building / facility. iii. Ensure the correct the procedures for erection, commissioning, testing and future maintenance. Conventional Lightning Arrester These are oldest concept in Lightning protection. The ability of the conventional rod is to concentrate electric field under the electric storm condition around the corona. The corona is observed in the near vicinity of the tip, as the field concentration created by its geometric shape will decrease rapidly with distance, provided the tips are really sharp. The conventional rod offers a cone of protection based upon its installed height above the structure.it assume a positive angle from projections and structural components within are deemed to be protected against direct strikes. Angles of 45 are the general case protection angle for these rods. With a Conventional Lightning Rod of height 1 meter installed at the roof top of the building will be able to give an area of protection of meters sq. So for a building with top area of say 5 m x 5 m = 25 sq meter, approximately 8-9 Lightning Conductors shall have to be used. However, limitations of this concept particularly manifest themselves when applied to very tall structures. Normally Conventional rod is commanded non-effective above m height and continuously reduces the protection angles with increased structure height. Also when we are installing these lightning conductors on the building we have to install maximum nos. of conventional rods to cover maximum area and each rod requires separate down conductor with earthing and each earthing has be bonded with each other. This makes the system very complicated and costly. It also will require more maintenance and typically considering the Building protection against the lightning, the use of multiple numbers of rods defaces the buildings. Advanced Technology based on Ion generator The result of many years of ongoing field research is the Advanced Lightning protection system. This unit provides the design engineer with an air termination relatively free of space charges, which is capable of creating ionization and which concentrate electric field to release free electron on the approach of a lightning leader. As a result mostly only one lightning conductor is required against a large number of Conventional Lightning conductors. This Advanced Lightning conductor is a dynamic device which has a very strong central ion generating system that is able to generate ions and requires no external source of power supply. This remarkable terminal has the ability to concentrate only the electric field, which occur in microsecond time slot as the leader charges approach to ground. The unique lightning protection system has been designed to provide repetitive electrical discharge only during the time of approach of the downward Leader. If we have to install this protection device to a certain Building, we require only One Lightning conductor, only one down conductor with 3 earth pit and which will protect the entire buildings, monuments and surrounding area from direct lightning damages. CONSTRUCTION: Metal Used: Stainless steel, wheather proof, chemical reaction proof and non corrosive, making it a fit and forget installation. Lightning Intercepting Rod: It is again a stainless steel portion which intercepts lightning. Electro-atmospheric Energy Block: The portion within the high tension stroke generator Ion Electrodes: These provides high tension strokes which are produced in high tension stroke generator to form ion. Earth Connector: Stainless steel portion which transfers the lightning discharge to ground conductor. Pipe Connection Adaptor: Portion through which lightning rod is connected to 2 pipe which is used to as shaft to raise the lightning conductor.

TESTS AND CERTIFICATIONS: sabo 1. METU Electric Electronic high tension Lab test certificate as per NFC 17-102 2. Lightning conductor lab of Beijing Lightning protection device test center 3.

3 TESTS AND CERTIFICATIONS: sabo 1. METU Electric Electronic high tension Lab test certificate as per NFC Lightning conductor lab of Beijing Lightning protection device test center 3. GOST certificate 4. CE certificate 5. ISO certificate All LIVA lightning conductors are serial numbered and each carry 30 years Warranty. In house test certificate for each lightning conductor can also be submitted on request. Live Test Video is also available. PROTECTION RADIUS: Lightning conductor is categorised based on area or radius within which it provides protection. Radius of protection of lightning conductors is calculated based on following formula derived by NFC : Rp= h(2d-h)+δl(2d+δl) Where Rp Radius of protection in a horizontal plane situated at a vertical distance h of lightning conductor h - Height of top of lightning conductor above area to be protected D - Lightning advancement step or leaping interval of lightning along the way. D=20m for Level I protection, D=30m for Level II, D=45m for Level III protection and D=60m for Level III protection as per NFC standard. ΔL Distance to catch lightning in ΔT period ΔT Early Ionisation time period / Initiation advance time / Early Streamer Warning Time ΔL (m) = V (m/µsec) X ΔT (µsec) For calculation purpose, V to be considered as 1 m/µsec. So, higher ΔT active reaction time of lightning conductor is better. Lightning conductors with higher ΔT intercepts lightning faster and provides wider protection area. It is recommended to used lightning conductors with ΔT > 60 µsec. Level of protection: It is defined as the risk of lightning strike on a structure. It depends upon the various factors like Dimensions of building, structural & environmental coefficients, structure contents & occupancy, lightning density or number of lightning or thunderstorm days, etc.

4 sabo C=C2.C3.C4.C5

sabo Steps to ensure Correct Lightning Protection System with the Advanced Ion generating Lightning Conductor Step 1 Calculation of Risk Assessment or The Protection Level for the Building /

5 sabo Steps to ensure Correct Lightning Protection System with the Advanced Ion generating Lightning Conductor Step 1 Calculation of Risk Assessment or The Protection Level for the Building / structure The Lightning risk is assessed using various criteria for determining the protection need and required protection level. The various factors taken into consideration are as follows: - --Environment of building (Coefficient C1) -- Type of construction (Coefficient C2) -- Structure Contents (Coefficient C3) -- Structure occupancy (Coefficient C4) --Consequence of lightning strikes (Coefficient C5) Separate application form is enclosed for user to send us the data so that the protection level can be calculated. This risk assessment / protection level calculation is done as per the International Standards i.e. NFC, IEC etc. In case the user needs the details, the same can provided on request.

6 LIVA LIGHTNING CONDUCTOR APPLICATION FORM sabo CUSTOMER DETAILS: Customer: Address: Dimension of the Building Length of the building: Date: Contact Name: Telephone: Fax: Place/city where building is located Width of the Building: Height of the building: ENVIRONMENTAL COEFFICIENT (Tick the Appropriate Box) Surrounded by structure or tress of the same height or higher : Surrounded by Smaller Structure : Isolated: No other structure within a distance equal to 3 times height : STRUCTURAL COEFFICIENT (Tick the Appropriate Box): Metallic Common Flammable Roof Walls STRUCTURAL CONTENTS COEFFICIENT OF THE BUILDING (Tick the Appropriate Box): No value : Standard Value or normally flammable : High value or particularly Flammable : Exceptional value, irreplaceable or highly flammable, explosive : STRUCTURE OCCUPANCY OF THE BUILDING (Tick the Appropriate Boxes): Unoccupied : Normally Occupied : Difficult Evacuation : LIGHTNING CONSEQUENCE (Tick the Appropriate Boxes): Service Continuity not required : Consequences on the environment : Service continuity required without consequences on the environment : Detail of any other structure/mast etc installed on the roof:

7 Step 2: Ensure the correct selection of the Advanced Lightning Protection Conductor sabo Protection against direct lighting strikes is designed to capture the lighting impact, channel it and discharge it to the earth for a particular dimensional area of the structure. After evaluating the lightning risk and choosing the protection level, the second phase involves choosing the kind of Lightning Conductor which shall be able to cover the required dimensions. The following is the table that defines the radius of protection that can be achieved by the various models of Lightning Conductor. One model out of these have to be selected which can cater to the protection Level calculated in Step 1 and as per this level is able to cover the dimensions to be protected. On the basis of the data received from the customer as per the step 1, the radius of the protection for the building is calculated as per the table given below: - ORDER CODE LENGTH (MM), WEIGHT (KG) PACKING DIMENSIONS(M M) ΔT (µsec) PROTECTION RADIUS (M) AT 4M. LEVEL IV LEVEL I LEVEL II LEVEL III LAP-DX MM, 5KG 250*250* LAP-AX MM, 5KG 170*170* LAP-BX MM, 4.8KG 170*170* LAP-BX MM, 4.2KG 130*130* LAP-CX MM, 2.4KG 130*130* LAP-CX MM, 2.3KG 130*130* ESE CUM PIEZOELECTRIC ADVANCE LIGHTNING CONDUCTOR LAP-PEX MM, 15KG 160*160* Example: - Suppose the parameter, which we have selected for the building protection, is as below: - Length of the building = 30 m Width of the building = 30 m Height of the building = 5 m Suppose the Level of Protection on the basis of the calculation comes to be as Protection Level - I and radius of protection required is 43 m to provide complete protection to the building. Then if we use the LAP CX 040 model to install at a 4 m height above the roof of the building, then the radius of the protection will be 39 m, which will, not able to provide the complete protection to the building. So we have to suggest the installation of LAP CX 070 lightning conductor at height of 4 m to cover a radius of 47 m so that it will be able to provide the complete protection for the building which has a radius of 43 m.

8 Step 3: Using correct procedures for Erecting, commissioning, testing and future maintenance. sabo 1. As per NFC standard, if width of building is more than 2 times height of the building or building height is more than 28m, then 2 down conductors should be routed from the nearest opposite path of the lightning conductor. 2. Care should be taken in routing the down conductor. It should be routed through the straight and shortest path to earth and also such that all gas pipes, water pipes, wires & cables, etc. should be minimum 1-2m far from it. Sharp bends should be avoided. In any case, bends should have radius of 20cm. External open routing of down conductor is better. 3. In case, metallic pipes / wires /cables are unavoidable then it should be separated by placing them inside a metallic screen which should extend 1m beyond the point of crossing. Such metallic screen should be connected to down conductor. 4. Down conductors should be attached to the side wall of the structure to be protected by means of 2-3 fixings per m. All the down conductors are also connected by same material. 5. Drilling on down conductors should be avoided. 6. Each down conductor should be routed to Rubber or PVC pipe or sleeves in order to avoid risk of impact. 7. When external routing of down conductor is impracticable, then a dedicated duct should be made. Such duct should not be more than 2000sq.mm. If it is more than it or in case other wires, pipes / cables also pass through it then insulated non inflammable duct should cover down conductor. 8. When outside of the building or structure has a metal cladding or stone or glass curtain walls then the down conductor should be attached behind the cladding to the concrete wall or the load bearing structure. In such cases, conductive cladding components and supportive structure must be bonded to the down conductor at the top and bottom ends. 9. If external structure is completely metallic like a telecom or transmission tower and if electrical continuity is there, then, it is not necessary to use separate down conductor. Steel metallic structure can be used as down conductor as they are conductive and their internal resistance is <0.01Ohm. In such cases, ESE lightning conductors should be connected directly to the metallic frame which at the ground level is connected to earth termination system. In such cases, equipotential bonding should properly be done. 10. Down conductor should be earthed at minimum 2-3m apart from building and other earthing. Down conductor should be buried by minimum 1 feet below the ground. Non corrosive earthing compound should be poured below and above the down conductor to avoid corrosion. All the joints should be exothermically welded to avoid any weak joints and increasing life of complete lightning protection system. Preferred Installation Points: It is preferred to install lightning conductor over the topmost portion of the structure to be protected. However, the architectural aspects should be taken into consideration for fixing location of lightning conductor.

9 SPECIFICATIONS OF LAP-CX 070 ADVANCED ACTIVE ESE ION GENERATING TYPE LIGHTNING PROTECTION SYSTEM sabo Complete Lightning Protection System consists of following: 1. Active ESE Early Streamer Emission Air Terminal 2. Elevation Shaft / mast for raising Air terminal minimum 2m above the top of the structure to be protected. Ideally lightning air terminal should be installed at 4m height above the structure to be protected so that complete protection radius capacity of air terminal can be utilized. 3. Down conductor 4. Lightning counter 5. Earthing

10 sabo ADVANCED ACTIVE ION GENRATING ESE EARLY STREAMER EMISSION AIR TERMINAL / LIGHTNING CONDUCTOR LAP-CX070 SPECIFICATIONS: 1. Stainless steel material body, 700mm long and 3.1 Kg nett weight with pointed tip. 2. Based on Active Early Streamer Emission principle and consists of Ion Generator. 3. High early streamer warning time of ΔT31 µsec. 4. Provides protection radius of 72m in Level IV area / 64m in Level III area/ 55m in Level II area/ 47m in Level I at 4m height in accordance with NFC standard. 5. METU Electrical & Electronics test report as per NFC standard. 7. In each lightning conductor Serial number, model no., CE mark, hologram & OEM name is printed. 8. Every lightning conductor carries 30 years warranty. 9. Internal last inspection report of manufacturer will be provided with every serial numbered lightning arrester, if required. 10. Sigma test report 11. Temperature withstand test of -40ºC to +125ºC. 12. QA technic conformity certificate 13. TS EN ISO 9001:2008 certificate 14. BS EN ISO 14001:2004 certificate 15. Certificate of registration from World Intellectual Property Organisation 16. CE certification 17. Testable by means of external tester. 18. Designed as per NFC standard. 17. Suitable for all types of lightning discharges. 19. Suitable for all whether and climatic conditions and can be used in any terrain. 20. No use of battery or power source is required. Elevation Rod: The Advance lightning conductor height may be increased by means of an elevation rod of GI/ SS/ FRP with GI/Aluminium. The lightning conductor tip should be at least 2 meters higher than the highest point of the building that it protects, including antenna, cooling towers, roofs, tanks, etc. The Down conductor is attached to the Advance Lightning conductor by a connecting system located on the support rod. This connecting system consists of suitable mechanical devices providing long-lasting contact. The Down conductor should comply with the data as below: Down Conductor Material Remarks Minimum Dimensions Bare/Tin plated electrolytic Recommended for its good Strip: 30 x 2mm Copper conductivity and corrosion resistance Round section: 8mm Dia 18/ stainless steel Recommended in certain corrosive environments Strip: 30 x 2mm Round section: 8mm Dia A 5/L To be used on aluminum surfaces (cladding, curtain walls) Strip: 30 x 3mm Round section: 10mm Dia When Advance lightning conductors protect open areas such as playing fields, golf courses, swimming pools, camping sites, etc., they should be installed on specific supports such as lightning poles, pylons or any other nearby structures which enables in Advance lightning conductor to cover the maximum area to be protected.

sabo LIGHTNING COUNTER Lightning counter is of 6 digits of stainless steel material and have IP65 protection. It also comes in testable/ SMS / Email options.

11 sabo LIGHTNING COUNTER Lightning counter is of 6 digits of stainless steel material and have IP65 protection. It also comes in testable/ SMS / options. It is used to provide the information of no. of lightning strikes our lightning protection system has safely discharged. It should be installed at eye level. Technical specifications: Range: to Current discharge capacity >1KA Conductor size: 2.5sq.mm. to 70 sq.mm. Temp: - 50ºC to + 80ºC Degree of Protection: IP 65 / SMS transmission device needed to be installed in case lightning discharge records are needed in remote computer or mobile automatically during lightning strike. The device immediately send the or sms as desired in case of lightning event.

12 LIGHTNING CONDUCTOR & TESTABLE LIGHTNING COUNTER TESTER sabo

13 sabo TEST CLAMP / JOINT: Each down conductor should have a test joint for disconnecting it with earth for measuring the earth resistance. It should be installed generally at 2m height above the ground level. EARTHING: Each earth should consist following: 1. Copper bonded rod 17.2mm dia 1.8m long of 254 microns 1no. 2. NABL tested EREC having resistivity of Ώ-m 20kg 3. Earth chamber of 300mm approx. of CI / concrete / Brick / Polyplastic should be used as earth pit cover. Polyplastic earth pit is preferred since it can withstand all climatic conditions. 3 sets of above earthing should be made each minimum 2m apart and joined by 30*2mm / 8mm dia bare copper rope / 30*3.5mm dia braided copper cable. Suitable non corrosive clamps for connecting strip or cable to copper bonded rods may also be used. All the nuts and bolts should be of stainless steel. Exothermic welding should be done for connecting all joints of strip / cable / rod. POLYPLASTIC EARTH PIT CHAMBER (SABO-PEPC) MAIN FEATURES: Factory- built long holes for accessing pipes easily at site Made of heavy duty polyethylene for extra durability. Resistant materials- assuring long life. Green top cap matches the environment. DIMENSIONS At Top : 10 inches (254mm) At Bottom : 13 inches (330mm) Height : inches (260mm)

14 LIGHTNING CONDUCTOR INSTALLATION DETAILS WITH /SMS OPTION sabo

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16 sabo LIGHTNING CONDUCTOR INSTALLATION ACCESSORIES

SECTION LIGHTNING PROTECTION SYSTEM

SECTION LIGHTNING PROTECTION SYSTEM SECTION 16670 - LIGHTNING PROTECTION SYSTEM PART 1 - GENERAL 1.01 RELATED DOCUMENTS A. General: Drawings and general provisions of the Contract, including General and Supplementary Conditions and Division