EN 50522:2022

Earthing of power installations exceeding 1 kV a.c.

Publication date:   Aug 17, 2022

Scope

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.