Current edition lightning risk assessment: the edition is data, named on every report
Every figure Lumex computes is computed on one stated edition of one standard: IEC 62305-2:2024, NFPA 780-2026 or AS 1768:2021. The edition is stored with the assessment and printed on its report. For IEC 62305, national departures are selectable data with their source attached.
A current edition lightning risk assessment states which standard and which edition produced every figure, because the same building gives different answers under different editions.
Standards are revised, and a revision of a risk method is not a tidy update. It can change what is calculated, what it is judged against and which inputs count. A risk figure with no edition beside it cannot be checked, because the reader does not know which method to check it against. The edition is part of the answer.
This piece sets out the principle and how Lumex applies it. Every figure is computed on one stated edition: IEC 62305-2:2024, NFPA 780-2026 or AS 1768:2021. The edition is held as data on the assessment, never assumed. It is named on every report. For IEC 62305, where national regulation may set its own values, national departures are data too, each with its source. It sits beside the principle that every figure must be traceable and reproducible: a trace that leads to the wrong edition leads nowhere.
Two editions of one standard are two different risk models
IEC 62305-2:2024 is the third edition, and its Foreword records that it cancels and replaces the 2010 edition as a technical revision. The changes it lists are not small. Edition 3 brings in a single risk that combines loss of human life and loss by fire. It adds a frequency of damage for the internal systems of a structure. And it counts dangerous events from the ground strike-point density NSG instead of the flash density NG. A 2010 figure has no frequency term and was built from a different density, so it cannot be compared line for line with a 2024 figure.
The same holds elsewhere. The Preface of AS 1768:2021 says it was prepared to supersede AS/NZS 1768:2007, and that it was published as an Australian Standard rather than a joint one. NFPA 780 is revised on its own cycle, and its risk assessment sits in Annex L. Each of these is a separate method with its own inputs and its own tolerable values, so a number from one never carries across to another. For what changed, see the IEC 62305:2024 edition changes, the NFPA 780-2026 changes and AS/NZS 1768:2007 against AS 1768:2021.
How Lumex holds the edition as data, not as an assumption
In Lumex a standard is identified by two facts: which published standard, and which edition. That pair is stored on every assessment and decides everything done to it afterwards.
| Standard in Lumex | Stored identity | Named on the report cover |
|---|---|---|
| IEC 62305-2, Edition 3 | IEC-62305-2, 2024 | IEC 62305-2 Edition 3.0 (2024) |
| NFPA 780, Annex L | NFPA-780, 2026 | NFPA 780-2026 |
| AS 1768 | AS-1768, 2021 | AS 1768:2021 |
Stamped by the engine that ran
The standard and edition are written onto the assessment by the engine that computed its figures, never taken from a request. An assessment cannot be labelled with a standard it was not computed under.
Every later step follows it
Opening, editing, recomputing and printing all look up the standard by the identity stored on the assessment. Answers made under a different standard are refused, and nothing falls through to another standard's method.
Old work stays readable
A standard can stay available for its existing assessments while no longer being offered for new ones. Its assessments still open, recompute and print under the edition they were made on.
Where the edition appears on every report
The cover of every Lumex report carries a Calculation Standard line naming the standard and edition the figures were computed on. It is filled from the stored identity, not typed by anyone, so it cannot drift from the figures inside.
An IEC 62305 report goes one step further. A single sentence scopes every bare clause, equation and table reference in its tables to IEC 62305-2 Edition 3.0 (2024), so a reader can re-check any reference against the exact document. When a national annex replaces an IEC annex, the same sentence says so and names the national document that carries it. The assistant follows the same rule: a fact it quotes from a standard carries that standard's name and edition in front of the clause.
National departures from IEC 62305-2 are selectable, cited data
IEC 62305-2:2024 leaves room for countries to adjust it. Its Introduction says national or local regulation may fix the tolerable risk RT and the tolerable frequency of damage FT, as well as the calculation rules and parameter values of Annexes A, B, C and E. Its Foreword then lists practices that differ in five countries. Germany sets rp to 1 in every case and assumes PTWS of 1 for six named components. Greece assumes PTWS of 1 throughout. Italy judges the life risk and the fire risk against the tolerable value one at a time. The Netherlands and South Africa leave Annexes D and E out of usual studies.
Lumex holds these as jurisdiction profiles. A profile can fix the tolerable values, switch a rule such as the separate Italian comparison, force a parameter so a typed value cannot undercut it, and replace a single row of an annex table. Every profile and every replaced value must carry a citation, because a departure with no source cannot be told from an invented number. The default profile is IEC 62305-2:2024 with no national departures. Profiles for countries whose national text Lumex has not verified compute the IEC baseline and change only the name and citation. Where a country does not use the IEC risk method as its deciding rule, the picker marks the profile as advisory. See IEC 62305 in Germany, BS EN 62305 in the United Kingdom and Annexes D and E in national practice.
Profiles exist for IEC 62305 only. NFPA 780-2026 and AS 1768:2021 are each computed by their own published method. When a profile is applied, the report states the jurisdiction, the authority behind it and each departure, and a snapshot of all of it is stored with the figures, so a later correction to a profile never rewrites a report already issued.
What to ask of any lightning risk tool
Ask three things. Does the report name the standard and edition that produced its figures? Is that edition stored with the assessment, so reopening it next year gives the same method? And when a national rule changes a value, is the change visible on the report with its source? A spreadsheet named for an edition answers none of these on the page itself.
Lumex answers all three. Voltrace, its calculation engine, runs the method of the standard and edition you choose and shows the working behind every figure. The engineer submits the assessment and a reviewer approves it, as set out in the engineer signs, a reviewer checks. Read the other principles on why the activity record is only added to and independence from protection products, or see the standards Lumex supports and the platform.
Questions answered
Which editions of the lightning protection standards does Lumex use?
Why does the edition of IEC 62305-2 matter for a risk assessment?
Does a lightning risk report have to state the edition of the standard?
What are national departures from IEC 62305-2?
Can I apply national rules to an NFPA 780 or AS 1768 assessment in Lumex?
What happens to an old report when a national profile changes?
Lumex computes the method of the standard you choose, IEC 62305-2:2024, AS 1768:2021 or NFPA 780-2026, and shows the working. It does not certify a structure. You may not issue or submit a Lumex output until a competent person, qualified where the structure is located, has reviewed the inputs and the result and signed it.
The tolerable risk in IEC 62305-2 is not a fixed constant. Clause 7.3 NOTE 1 gives RT = 1 × 10⁻⁵ per year as a representative value of tolerable risk and adds that another value may be set once the case has been investigated in detail. Printed p.12 then lets national or local regulations fix RT, the tolerable frequency of damage FT, and the Annex A, B, C and E calculation rules and parameter values. Every IEC 62305-2 assessment in Lumex states the jurisdiction it was computed under and the values that applied.
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