Protection against lightning
Early streamer emission lightning protection


  • Definitions:
    • 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.

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
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.

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.

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

1.5 failure of electrical and electronic systems
permanent damage of electrical and electronic systems due to LEMP

1.6 failure current (
minimum peak value of lightning current that will cause damages




  1. Lightning protection system with Early Streamer Emission Air Terminal

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 Components of the lightning protection system
The installation may be composed of the following elements:

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

Figure 1 – Components of the lightning protection system



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.



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

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


2.3 Choosing The ESEAT Model

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

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.
STANDARDS           NFC17.102:2011
                                    TS EN62305


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


  1. ESE System Installation & Accessories

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.

3.2 ESE Tester

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 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





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.

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.

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