BS 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 2 In 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 3 The 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.