Deals with safety philosophy, quality assurance and engineering integrity, and specifies minimum requirements for the safety, including design, installation, maintenance, and operation under specified environmental conditions. The purpose is to provide the appropriate level of protection against damage from all hazards from these systems during their planned lifetime. Applies to WTGS with swept area equal to or larger than 40 m2. Is also concerned with all sub-systems, e.g. control and protection mechanisms, internal electrical systems, mechanical systems, support structures, foundations and the electrical interconnection equipment.