Introduction
THE Early Streamer Emission (ESE) lightning rods, Or ESE lightning rods, are based on a key principle: triggering the ascending tracer more quickly than the franklin simple rod . This time saving is called ignition advance (ΔT).
But to avoid commercial excesses and guarantee the safety of the installations, the standard NF C 17-102:2011 sets a clear limit: ΔT ≤ 60 microseconds.
What is the ignition advance (ΔT)?
- THE ΔT (expressed in µs) measures the time saved compared to a simple tip.
- This parameter is integrated into the standardized formula for calculating the protection radius (Rp).
- However, the Rp depends on three inseparable factors :
- The ΔT of the lightning rod (10, 25, 45 or 60 µs)
- There installation height (h) above the area to be protected
- THE protection level defined by the standard (I, II, III, IV), which corresponds to the severity of the risk to be covered
👉 Simplified example:
- A ESE of ΔT = 60 µs installed at a height of 5 m will not give the same Rp as a ESE of ΔT = 60 µs installed at a height of 20 m.
- Similarly, a protection level I (the most demanding) reduces the Rp compared to level IV.
The limit imposed by the NF C 17-102:2011 standard
- The fixed standard ΔT max = 60 µs.
- This ceiling is essential because:
- Beyond that, the results are not scientifically reliable.
- It avoids announcing unrealistic and dangerous rays.
- It guarantees a common basis for all manufacturers.
⚠️ Caution: the protection beam must not never be announced solely as a function of ΔT. It must always be calculated according to the standard formula, taking into account the level of protection chosen.
The case of LPS France products
At the house of LPS France, all our ESEs comply with the NF C 17-102:2011 standard.
- We offer a complete range: ΔT = 10, 25, 45 and 60 µs.
- Our technical documents systematically specify the Rp according to:
- the ΔT,
- the installation height,
- and the level of protection (I to IV).
👉 Our top of the range Paraton@ir goes further: in addition to being compliant, it is connected via LPS MANAGER, enabling real-time monitoring and traceability of lightning strikes.
Conclusion
The limitation of ΔT to 60 µs set by the standard NF C 17-102:2011 is a guarantee of seriousness and security.
But it is essential to remember that the protection radius (Rp) also depends on the installation height and the chosen level of protection.
👉 With its compliant ranges and connected solutions, LPS France provides reliable, transparent and innovative protection.