The new art. 443.4 of the CEI 64-8 V5 standard, in force since 1 March 2019, establishes:
"protection against transient overvoltages must be provided when the consequences of the effects of such overvoltages affect:
on human life, such as security services, medical assistance devices;
on public services and cultural heritage, such as the loss of public services, IT centers, museums;
on commercial or industrial activities, for example in the case of hotels, banks, industries, commercial markets, farms;
on a large number of people, for example in the case of large buildings, offices, schools ".
"for all other cases a risk assessment can be carried out, in order to determine whether protection against transient overvoltages is
necessary. If the risk assessment is not carried out, the electrical system must be equipped with a protection against internal
overvoltages ". In essence, in addition to verifying the need for an external LPS system according to CEI EN 62305-2 ("lightning rod"),
for each building a protection system against overvoltages must be designed ("dischargers"), to be installed in one or more switchboards. electric.