IEC 62305 in Greece

Greece reaches IEC 62305 the way its neighbours do. CENELEC adopts the international standard as EN IEC 62305, and the Greek national body, ELOT, publishes that text under a national reference. For the risk management part that reference is ΕΛΟΤ EN IEC 62305-2:2024. The clauses, the risk components and the equations come across unchanged, which is why a Greek specification and an international one describe the same method.

The naming is worth getting right on a document. The current series is IEC 62305 and its adoptions carry the IEC number in their designation, as in EN IEC 62305. A bare EN 62305 refers to the superseded series, Parts 1, 3 and 4 from 2011 and Part 2 from 2012, and is not the standard a current assessment is built to. If a specification you have been handed names that number, resolve which edition is actually intended before you calculate, because the edition decides the method.

None of this changes the method. The reference number tells you which national publication governs; the differing practices list tells you what that country changes. For Greece the answer to the first is the European adoption, and to the second it is P_TWS. For the wider picture of how adoption works, see IEC 62305 around the world.

Because P_TWS multiplies into the six probabilities above, fixing it at 1 leaves each of them at its unreduced value. The six components R_AT, R_AD, R_U, R_V, R_W and R_Z are therefore higher than the same building would produce under a plain IEC baseline calculation that declared a warning system, and the total risk R rises with them. Where the warning had also earned an evacuation credit through the presence factor P_P, the loss of life parts of R_B, R_C and R_M lose that credit as well.

The direction is one way in Lumex^™. Holding P_TWS at 1 removes any warning system credit, so the affected figures can only stay the same or rise. That direction comes from treating a value of 1 as no warning system at all, which is how the engine reads it; it is not a rule the standard states. So the Greek rule never rescues a structure that would otherwise fail; it can only push one that was passing over the line. That is the opposite of the Italian rule, which is more permissive than the baseline, and it is worth stating plainly because the two are often filed together as national departures without noticing they move in opposite directions.

The size of the difference is the size of the credit that was being claimed. A structure with no thunderstorm warning system already sits at P_TWS = 1 under clause B.2 NOTE 1, so the Greek rule changes nothing for it. The rule bites exactly where a warning system has been declared and a value below 1 selected, and it scales with how much reduction that selection was taking out of the calculation.

The decision that can flip is whether protection is needed at all. The verdict in IEC 62305-2 is a comparison of the computed risk against the tolerable value. A building carried just under that line by a declared warning system sits above it once the credit is removed. So the departure is not a rounding detail. It can be the difference between a report that says no protection is required and one that specifies a lightning protection system.

It is common to see the tolerable risk quoted as though IEC 62305-2 fixes it. It does not. Clause 7.3 NOTE 1 gives R_T = 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. The standard's introduction then lets national or local regulations fix R_T, the tolerable frequency of damage F_T, and the Annex A, B, C and E calculation rules and parameter values.

For Greece the standard records no national R_T, and Lumex^™ applies the representative 10⁻⁵ per year. If a project specification, a regulator or the authority having jurisdiction fixes another value, record it and compare the result against it outside the tool. That is a judgement to make and record at the start of a project, with whoever is entitled to make it, rather than a number to assume. It is also why a tool should resolve the tolerable value from the jurisdiction rather than carry it as a constant in the code.

For how national adoption works generally, and which designation applies in other markets, see IEC 62305 around the world. For the method the Greek rule modifies, read the IEC 62305-2 risk assessment, and for the arithmetic itself see how IEC 62305 risk is calculated.

Three other national departures are set out in their own pages: IEC 62305 in Germany, where the fire provisions factor r_p is 1 for all cases, IEC 62305 in Italy, where R_L1 and R_L2 are compared with the tolerable risk separately, and Annex D and Annex E in national practice, which covers the Netherlands and South Africa.

In Lumex^™ the jurisdiction is an input, not an afterthought. Selecting Greece forces P_TWS to 1 across every component of the IEC 62305-2:2024 calculation, both where the term appears directly and where it reaches a component through the presence factor, before the calculation runs, so the figures in the report are the Greek figures rather than baseline figures with a note attached. It is applied server side, which is the part that matters on a compliance job: a warning system declared in the inputs cannot pull a Greek assessment below what the regulator permits, because the credit is removed after the input is read and not left to the engineer to remember. The report then prints the departure with its citation, so a reviewer can tell a regulator's rule from a modelling choice. See the Lumex^™ platform.