Why are ignition advances > 60 µs misleading?

Introduction

Early Streamer Emission (ESE) lightning rods – or early streamer emitters (ESE) – stand out from the franklin simple rod by one essential parameter: the ignition advance (ΔT), that is, the time they gain to emit an upward tracer. The higher the ΔT, the greater the theoretical protection radius. Some brands, in search of competitive advantages, display ΔTs greater than 60 µs (80 µs, 100 µs, or even more) to promise a wider protection area.

But these values ​​are contrary to standards and mislead the end user. According to standard NF C 17-102:2011 and international standards (UNE 21186/2118), the maximum ΔT allowed is 60 µs.

What the official standards say

• • NF C 17‑102:2011 : sets the framework for the design and testing of ESEs. It specifies that the protection radius depends on the level of protection, the installation height and the ΔT. Above all, it indicates that the maximum value of ΔT for protection calculations is 60 µs.

• • UNE 21186 : these Spanish standards complement NF C 17-102. They remind us that a ESE must have a ΔT strictly greater than 10 µs and that the maximum admissible value is 60 µs, even if higher results have been measured in the laboratory.

• • Laboratory tests : serious manufacturers have their products certified in high-voltage laboratories. The tests define the difference in ignition time between the ESE and a simple tip and validate the ΔT value. Our catalogs clearly state that for 60 µs models, the ΔT used in the calculations is limited to 60 µs in accordance with paragraph 5.2.2 of NF C 17-102.

Why this 60 µs limit?

The standards do not set this threshold at random:

1. 1. Scientific reliability : Beyond 60 µs, laboratory test results become unstable. Reliable manufacturers therefore limit their calculations to this value.

1. 1. Comparability : By imposing a common cap, all brands are assessed on the same basis. This prevents false commercial promises and protects users from overestimated protection radii.

1. 1. Regulatory compliance : in calls for tenders or certifications, only ESEs respecting this limit can be legally installed.

Commercial drifts: promises beyond 60 µs

Despite these clear rules, some brands display firing advances of 80 µs, 100 µs or even more, suggesting that their ESE protects a huge surface area. These non-compliant values ​​pose several problems:

• • Lack of normative validation : the standards impose ΔT ≤ 60 µs, so a radius calculated with a ΔT of 80 µs has no regulatory basis.

• • Deceptive protection rays : by artificially increasing the ΔT, some sellers claim to cover radii of 200 m or more. However, standard calculations use only the certified value (≤ 60 µs).

• • Risks to facilities : sizing based on an unrealistic ΔT may leave areas unprotected, increasing the risk of direct impact.

Example: comparison table

ΔT (µs)	Compliance	Noticed
10, 25, 45, 60	Complies with NF C 17-102	Values ​​validated by tests
> 60 (80, 100…)	Non-compliant	No normative recognition; misleading rays

How to choose a ESE without making a mirod?

1. 1. Request certification : require a high voltage laboratory test report showing the certified ΔT value and compliant with standard NF C 17-102:2011.

1. 1. Check the advertised value : if it exceeds 60 µs, run away: it is non-compliant. The ΔT used for calculations must be limited to 60 µs.

1. 1. Analyze brand transparency : serious manufacturers publish protection radius tables for each ΔT and protection level (I to IV).

1. 1. Prioritize maintenance and monitoring : solutions equipped with testers (wired or remote) ensure simplified maintenance and traceability, as offered by the ranges Ellips Or Paraton@ir + Contact@ir System.

LPS France 's compliant solutions

LPS France, a renowned French manufacturer, offers ranges Ellips And Paraton@ir who scrupulously respect the standards:

• • ΔT available: 10, 25, 45 and 60 µs, always lower than or equal to the regulatory threshold.

• • Control and monitoring : each lightning rod can be tested via a wired tester or for the Paraton@ir thanks to architecture Contact@ir with the application LPS Manager, offering real-time diagnosis.

• • Compliance : the protection radii are calculated according to the standardized formula (protection level, installation height, ΔT) and presented transparently.

Conclusion

The lead time is an essential parameter for early streamer emission lightning rods. No recognized standard allows a ΔT of 60 µs to be exceeded.Brands that advertise longer times are not complying with the rules and putting your facilities at risk. To ensure the safety of your buildings and the compliance of your lightning protection, demand a certified ESE, request test reports, and refuse promises beyond 60 µs. LPS France, with its Ellips and Paraton@irranges, is committed to this approach of transparency and reliability.