This standard applies to type-tested assemblies (TTA) intended for use on construction sites, i.e. temporary places of work to which the public do not generally have access and where building construction, installation, repairs, alteration or demolition of property (buildings) or civil engineering (public works) or excavation or any other similar operations are carried out. These assemblies may be transportable (semifixed) or mobile.This standard does not apply to assemblies for use in the administrative centres of construction sites (offices, cloakrooms, assembly rooms, canteens, restaurants, dormitories, toilets, etc. ).The nominel primary voltage and the