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
