EN 50522:2022

This document is applicable to specify the requirements for the design and erection of earthing systems of electrical installations, in systems with nominal voltage above 1 kV AC and nominal frequency up to and including 60 Hz, so as to provide safety and proper functioning for the use intended.NOTE 1 The technical and procedural principles of this document can be applied when 3rd parties’ installations and facilities are planned and/or erected in the vicinity of HV electrical power installations.For the purpose of interpreting this document, an electrical power installation is considered to be one of the following:a)substation, including substation for railway power supply;b)electrical power installations on mast, pole and tower;switchgear and/or transformers located outside a closed electrical operating area;c)one (or more) power station(s) located on a single site;the electrical power installation includes generators and transformers with all associated switchgear and all electrical auxiliary systems. Connections between generating stations located on different sites are excluded;d)the electrical system of a factory, industrial plant or other industrial, agricultural, commercial or public premises;e)electrical power installations on offshore facilities for the purpose of generation, transmission, distribution and/or storage of electricity;f)transition towers/poles between overhead lines and underground lines.The electrical power installation includes, among others, the following equipment:—rotating electrical machines;—switchgear;—transformers and reactors;—converters;—cables;—wiring systems;—batteries;—capacitors;—earthing systems;—buildings and fences which are part of a closed electrical operating area;—associated protection, control and auxiliary systems;—large air core reactor.NOTE 2In general, a standard for an item of equipment takes precedence over this document.This document does not apply to the design and erection of earthing systems of any of the following:—overhead and underground lines between separate installations;NOTE 3The standard, EN 50341 series Overhead lines exceeding AC 1 kV, specifies requirements for the design and erection of earthing systems in overhead lines.—electrified railway tracks and rolling stock;—mining equipment and installations;—fluorescent lamp installations;—installations on ships and off-shore installations;—electrostatic equipment (e.g. electrostatic precipitators, spray-painting units);—test sites;—medical equipment, e.g. medical X-ray equipment.NOTE 4 The scope of this document does not include the requirements for carrying out live working on electrical power installations.NOTE 5 The scope of this document considers safety requirements for HV installations and its influences on LV installations. For electrical installation up to 1 kV, the standard IEC 60364 series applies.