Why are ignition advances > 60 µs misleading?

Introduction

Early streamer emission (ESE) lightning rods – or early streamer emitters (ESE) – differ from franklin simple rod by one essential parameter: the ignition advance (ΔT)This refers to the time they gain in emitting an upward tracer. The higher the ΔT, the greater the theoretical protection radius. Some brands, seeking a competitive advantage, advertise ΔT values ​​exceeding 60 µs (80 µs, 100 µs, or even more) to promise a larger protection zone.

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 permissible ΔT is 60 µs.

What the official standards say

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

• • A 21186 These Spanish standards complement NF C 17-102. They reiterate that a ESE must have a ΔT strictly greater than 10 µs and that the maximum permissible value is 60 µs, even though higher results have been measured in the laboratory.

• • Laboratory tests Reputable manufacturers have their products certified in high-voltage laboratories. The tests define the difference in ignition time between the ESE and a simple probe and validate the ΔT value. Our catalogs clearly state that for the 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 arbitrarily:

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

1. 1. Comparability By imposing a common ceiling, all brands are evaluated on the same basis. This prevents false marketing claims and protects users from overestimated protection levels.

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

Commercial excesses: promises beyond 60 µs

Despite these clear rules, some brands advertise ignition advances of 80 µs, 100 µs, or even more, giving the impression that their ESE protects a huge area. These non-compliant values ​​pose several problems:

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

• • Misleading protective radii By artificially increasing the ΔT, some sellers claim to cover radii of 200 m or more. However, Standardized calculations use only the certified value (≤ 60 µs).

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

Example: comparative table

ΔT (µs)	Compliance	Noticed
10, 25, 45, 60	Compliant with NF C 17-102	Values ​​validated by testing
> 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 conforming to standard NF C 17-102:2011.

1. 1. Verify the advertised value If it exceeds 60 µs, avoid it: it's non-compliant. The ΔT used for calculations must be limited to 60 µs.

1. 1. Analyze brand transparency : reputable manufacturers publish tables of protection radii for each ΔT and level of protection (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 product ranges Ellips Or Paraton@ir + Contact@ir System.

LPS France 's compliant solutions

LPS France, a renowned French manufacturer, offers product ranges Ellips And Paraton@ir which scrupulously adhere to the standards:

• • Available ΔT values: 10, 25, 45 and 60 µs, always less 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 the architecture Contact@ir with the application LPS Manageroffering real-time diagnostics.

• • Compliance : the protection radii are calculated according to the standardized formula (level of protection, installation height, ΔT) and presented in a transparent manner.

Conclusion

Early flashover is an essential parameter of early flash lightning rods. No recognized standard allows a ΔT exceeding 60 µsBrands advertising longer response times are not complying with regulations and are endangering installations. To guarantee the safety of your buildings and the compliance of your lightning protection, demand a certified ESE (Power Distribution Actuation), request test reports, and reject promises exceeding 60 µs. LPS France, with its Ellips and Paraton@irproduct lines, is committed to this approach of transparency and reliability.