IEC 62305-2 · Ed. 3:2024 · validation

How the risk engine is validated.

A risk assessment decides whether a structure needs protection — and how much. So the arithmetic behind the verdict is checked against known answers, not just written and trusted. Here is how.

Three layers, not one claim

The whole value of the tool is that the number is right, so it is checked three independent ways.

01 · pinned

Every factor cites its clause

Collection areas, event rates, probabilities and loss values are each resolved from IEC 62305-2 Ed. 3:2024 with the clause or table printed beside them — implemented to the current edition, not an older one.

02 · reconciled

Reproduces known answers

The engine is run against the standard's own worked case studies and against full independent hand calculations — every collection area, event rate, factor and risk component matched figure by figure.

03 · shown

The working is on the report

Each report prints the derivation chain and the resolved per-zone factors, so an engineer of record can reproduce the risk from the printed numbers exactly — the unprotected case and the projected one.

What it is reconciled against

Standard case studies

The engine reproduces the standard's own Annex F worked case studies — a country house, an office block and a hospital — down to every collection area, annual event rate, resolved factor and risk component the standard prints. This is the strongest possible check: the answer key is the standard itself.

Full hand calculations

Two complete reference structures — a rural office with overhead power and telecom lines, and a three-zone suburban office — are worked entirely by hand to the 2024 conventions and reproduced by the engine to every zone component, the governing verdict, and the projected risk after the recommended protection. Any change that would move one of those numbers is caught automatically before it can ship.

Built to the 2024 edition, deliberately

The 2024 edition changed how risk is handled — it is now evaluated and judged per risk zone against the tolerable limit, with no structure-wide sum, and the older edition's occupancy scaling is gone. Voltbench implements the 2024 method, so its results differ by design from tools and worked examples still on the previous edition. What changed, and why, is written up in this guide.

See the working for yourself

The sample report shows the full derivation and the resolved per-zone factors on one fixed building. Read it, then assess your own structure free on screen.

Engine lightning-0.4.0-iec2024 · Voltbench v0.1.0

Read a full sample report ↗ Assess your structure — free

Voltbench is a calculation aid for qualified electrical engineers. Its outputs support, and do not replace, the professional judgement of a licensed engineer of record, who remains responsible for the assessment and its verification against the governing standard.