DS/EN 50522:2011

Earthing of power installations exceeding 1 kV a.c.

This European Standard 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 a.c. and nominal frequency up to and including 60 Hz, so as to provide safety and proper functioning for the use intended.*For the purpose of interpreting this standard, an electrical power installation is considered to be one of the following:*a) substation, including substation for railway power supply;*b) electrical 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 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.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 In general, a standard for an item of equipment takes precedence over this standard.This European Standard does not apply to the design and erection of earthing systems of any of the following:- overhead and underground lines between separate installations;- electric railways;- 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.*This European Standard does not apply to the requirements for carrying out live working on electrical installations.