Every year, lightning causes thousands of damages to infrastructure worldwide—industrial buildings, ATEX sites, data centers, and hospitals. In Europe and internationally, the implementation of an early streamer emission (ESE) lightning rod is the most widespread technical solution for protecting these critical structures. However, choosing the right equipment and installing it correctly are essential.
This article guides you step-by-step through the selection and installation of a ESE, based on international reference standards: IEC 62305 (international standard, series 1 to 4) and NF C 17-102 (French standard specific to ESEs). Furthermore, you will discover how LPS Manager simplifies the monitoring and compliance of your installations.
What is an early streamer emission (ESE) lightning rod?
A ESE is an active lightning protection system that emits an electrical pulse to initiate an upward leader before the lightning strike. As a result, it intercepts the lightning by attracting the arc channel to a calculated distance from the structure to be protected.
It differs from the single-rod (or Franklin) lightning rod primarily in its greater protection radius, calculated according to standard methods. Indeed, the NF C 17-102 standard precisely defines the calculation methods for the protection radius based on the protection level (LPL) and the early flash time (ΔT) specific to each model.
- Correct terminology in French : we speak of ESE — Paratonnerre à Dispositif d'Apriming (never "paratonnerre ESE" in a French-speaking context)
- Applicable standards : NF C 17-102 for design and installation; IEC 62305 for overall risk analysis
- Areas of application : industry, services, ATEX, classified ICPE sites, public access buildings (ERP)
The standards governing the installation of a ESE
IEC 62305: the international reference standard
The IEC 62305, in force in more than 60 countries, is structured in four complementary parts:
- IEC 62305-1 : General principles for protection against lightning
- IEC 62305-2 : Risk management (lightning risk analysis, calculation of the level of protection)
- IEC 62305-3 : Physical damage to structures and human risks (implementation of the LPS)
- IEC 62305-4 : Electrical and electronic systems in structures
Therefore, any lightning protection installation must be considered within this overall framework before selecting the appropriate type of lightning rod. The ground lightning density Ng (used in FD C 17-108 and IEC 62305-2) is a key parameter in this analysis.
NF C 17-102: the standard specific to ESEs
In addition, the French standard NF C 17-102 specifically governs the design, installation, verification, and maintenance of early streamer emission (ESE) lightning rods. It defines, in particular:
- The method for calculating the protection radius according to the ΔT of the ESE
- Mounting height requirements (minimum 2 m above the highest point)
- Down conductors and connections to the grounding rod
- Periodic verification intervals (annual and post-impact)
However, it should be noted that the NF C 17-102 standard applies in addition to, and not in place of, IEC 62305. These two standards are therefore complementary.
How to choose your ESE: the essential criteria
The level of protection (LPL)
First, the required lightning protection level (LPL) must be determined by the IEC 62305-2 risk analysis. This level ranges from LPL I (maximum protection, for very high risk structures) to LPL IV (standard protection).
In practice, the higher the LPL, the greater the required effectiveness of the ESE, and the larger the protection radius must be. Thus, an ATEX site or a hospital will generally require an LPL of I or II.
The lead time to initiation (ΔT)
Next, ΔT is the main characteristic of a ESE (Powered Discharge Amplifier). It represents the lead in microseconds with which the ESE triggers its arcing compared to a simple rod lightning rod. Therefore, it directly determines the protection radius calculated according to NF C 17-102.
- Larger ΔT → larger protection radius
- ΔT certified by an accredited laboratory (compliant with NF C 17-102 or NF EN 50164-1)
- Verify the traceability of the tests: test report provided by the manufacturer
The installation environment
Furthermore, the environment must be taken into account when choosing a ESE. Specifically, several factors come into play:
- Corrosive atmospheres : stainless or hot-dip galvanized materials required
- ATEX zones : the ESE must be passive (without a power source) or ATEX certified
- Structure height : influences the mounting and configuration of the downpipe
- Presence of obstacles : verify that the protection radius actually covers the area to be protected
Key steps in a compliant ESE installation
1. Preliminary lightning risk assessment
Before any installation, a lightning risk assessment according to IEC 62305-2 is essential. This allows for the calculation of the structure's risk level and the definition of the necessary level of protection.
This study takes into account the ground lightning strike density Ng (expressed in strikes/km²/year), the surface area of the structure, its use, and the consequences of an impact. Ultimately, it determines all subsequent technical choices.
2. ESE Positioning
The ESE must be positioned at least 2 meters above the highest point of the structure (including antennas, chimney stacks, etc.). Then, calculating the protection radius ensures that the entire area to be protected is covered.
However, if the structure has complex shapes or distant annexes, several ESEs may be necessary. LPS France assists its clients in this sizing process.
3. Implementation of downhill drivers
Down conductors carry lightning current from the ESE to the grounding electrode. They must be installed with the straightest possible route, without loops or sharp angles, to minimize impedance.
- Minimum cross-section: 50 mm² in copper or 70 mm² in aluminum (NF C 17-102)
- Minimum distance from windows and openings: comply with separation rules
- At least 2 descents for structures with a perimeter of more than 20 m
4. Grounding
Ultimately, the quality of the grounding connection determines the effectiveness of the entire system. The ground resistance must be less than 10 Ω (and ideally less than 1 Ω for sensitive sites).
Therefore, interconnection with other earth masses and systems (equipotentiality) is mandatory to avoid dangerous potential differences in the event of a lightning strike.
Verification and maintenance: obligations after installation
A ESE installation doesn't end with commissioning. Indeed, the IEC 62305-3 standard mandates periodic checks to maintain compliance over time:
- Annual verification : visual inspection and earth resistance test
- Post-impact verification : full inspection within 48 hours of a detected impact
- Renewal of the risk assessment : in the event of significant structural changes
Furthermore, document traceability is essential, particularly for sites subject to regulations (ATEX, ICPE, ERP). Each intervention must be recorded in a technical file.
To simplify this monitoring and ensure compliance over time, LPS Manager offers a platform dedicated to managing lightning cases, with automatic alerts for verification deadlines, report generation and access to lightning data via Strike Radar.
ESE lightning rods from LPS France
LPS France offers a complete range of certified ESEs to meet all levels of protection and all environments:
- Paraton@ir : Standard ESE, available in several versions depending on the required ΔT
- Ellips : High-performance ESE for areas with high lightning strike density
- ATEX versions are available for areas at risk of explosion.
In practical terms, each product comes with its certified test report and detailed installation guide. LPS France also assists you with the sizing and monitoring of your installations, throughout Europe and internationally.
Conclusion
In summary, choosing and installing a ESE lightning rod that complies with IEC 62305 and NF C 17-102 standards requires a methodical approach: risk analysis, selection of the level of protection, rigorous sizing and periodic checks.
LPS France supports you at every stage, from the initial study to annual maintenance. For optimal long-term management of your lightning protection projects, discover LPS Manager, the leading software for lightning protection professionals.
Need a quote or technical advice? Contact our team of experts — we work on all types of sites in Europe, Africa and internationally.
