Protection against lightning Early streamer emission lightning protection systems

1 Definitions:

  1. 1.1 early streamer emission lightning protection system (ESESystem)

    complete system based on one or more ESEAT and all elements to safely conduct lightning to earth in order to protect a structure, facility or open area against direct lightning impact.

  2. 1.2 early streamer emission air terminal (ESEAT)

    air terminal generating a streamer earlier than a simple rod air terminal when compared in the same conditions NOTE - An early streamer emission air terminal is made up of a striking point, an emission device, a fixing element and a connection to the down conductors.

  3. 1.3 ESEAT efficiency (ΔT)

    difference expressed in micro-seconds between the emission time of an ESEAT and an SRAT measured in a laboratory under the conditions defined in this standard.

  4. 1.4 external ESE System isolated from the structure to be protected

    LPS with an air-termination system and down-conductor system positioned in such a way that the path of the lightning current has no contact with the structure to be protected NOTE: In an isolated LPS, dangerous sparks between the LPS and the structure are avoided

  5. 1.5 failure of electrical and electronic systems

    permanent damage of electrical and electronic systems due to LEMP

  6. 1.6 failure current (Ia)

    minimum peak value of lightning current that will cause damages

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2. Lightning protection system with Early Streamer Emission Air Terminal

  1. 2.1 Need of protection

    The need for protection is determined according to many parameters including the lightning flash density of the considered area. A risk analysis method is proposed in Annex A. The lightning flash density is given in annex B or by local data including for example detection network, maps and statistics. NOTE 1: Other considerations may lead to take the decision to adopt protection measures for reasons other than statistical ones. For example, compulsory regulations or personal considerations since some factors cannot be estimated: the wish to avoid risk to life or to provide safety to the occupants of a building may require the use of protection, even though the calculated risk is under the tolerable level.
    NOTE 2 Different normative documents give some risk analysis methods that can be used.

  2. 2.2 Components of the lightning protection system

    The installation may be composed of the following elements:

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    1. 1- One or more ESEAT
    2. 2- Connection component
    3. 3- One or more specific down-conductors
    4. 4- A test joint for each down-conductor
    5. 5- One earth termination for each specific down-conductor
    6. 6- Foundation earth electrode (earthing of the structure)
    7. 7- Electric power cable
    8. 8- Main electric power distribution box with SPD
    9. 9- Main telecom distribution box with SPD
    10. 10- Telecom cable with SPD
    11. 11- One or more equipotential bonding bars
    12. 12- One or more equipotential bondings between earth terminations
    13. 13- Disconnectable bonding device
    14. 14- One or more equipotential bondings (direct or via an Isolating Spark Gap).
    15. 15- Main earthing bar
    16. 16- Electric equipment
    17. 17- Metallic pipe
    18. 18- One or more equipotential bondings through a spark gap or flexible braids
    Figure 1 - Components of the lightning protection system
  3. 2.3 Protection Radius

    ESE lightning rods use active ionization system that allows to have a larger protection radius when compared to conventional lightning rod systems. The installation of an ESE lightning rod should follow a different criteria from Faraday Cage method.

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    The protection radius of an ESEAT is related to its height (h) relative to the surface to be protected, to its efficiency and to the selected protection level

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    Calculation is based on standards NFC17.102:2011 and UNE
    21.186: 2011. Please view the norms for complete technical details

  4. 2.3 Choosing The ESEAT Model

    1. 1.1 After specifying the protection level, you can choose the appropriate model of ESE lightning rod using the following protection radius (Rp) table:

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      INDEX ΔT: Early streamer emission of an ESE lightning rod, determined by laboratory tests.
      LEVEL: Level of protection required by a particular building, depending on the operations carried out and various other factors.
      h (m): Distance between the lightning rod and the roof level, optimal:6 meters.
      TS EN62305

    2. 1.2 The first column of the table Rp(m) indicates the elevation of the ESE lightning rod above the highest point of the structure within the protection zone.

    3. 1.3 To obtain elevation, a mast, pole, tower, or part of the structure (such as chimney, antenna, etc.) must be used.

    4. 1.4 The minimum elevation should be 2 meters. The optimal level of elevation is5 or 6 meters, because below that level the radius of protection decreases rapidly and above that level, the increase is very limited.

    5. 1.5 It is recommended to install the ESE lightning rod at one point to cover the maximum area. To specify the installation point, the top plane of the building roof can be used.

    2.2. Advantages of ESE lightning rods

    • • Cost-effective solution

    • • Provides an active protection to the whole building

    • • Protects surrounding areas

    • • Requires less conductors and earthing accessories

    • • Easy to install and maintain, requiring less workforce

  5. 3. ESE System Installation & Accessories

    1. 3.1 lightning event counter

      A lightning strike counter is used to count the number of strikes. It should be installed on the mast or wall, directly on down conductor and above the test clamp and, in any case, at height about 2 meters above the ground level. It shall comply with EN 62561-6.

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    2. 3.2 ESE Tester

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      Tester lets you check the status of your ESE lightning conductor. With TESTER, you are able to check if there is a short circuit or a fault in the ion generator immediately by simply connecting the cable to the ESE conductor and pressing the button on the testing device.

      When pressing the button, the GREEN LED indicates full
      functionality, the RED LED indicates the device is not
      properly connected and the YELLOW LED indicates there is a short circuit

    3. 3.3 ESE Solar Tester

      Solar Tester let you test E.S.E. terminals remotely. The testing device stores energy to operate for 24 hours by a daily exposition of 5-7 hours of sun light

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    4. 3.4 Roof Conductor Holder:

      Available in plastic or other materials, this accessory serves to keep the cable suspended on a flat surface and avoid contact with unwanted objects.

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    5. 3.5 Test Joints:

      Each down-conductor should be provided with a test joint in order to disconnect the earth termination system for enabling measurements.

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      Test joints are usually installed at the bottom of the down-conductors.