Specifies mechanical tests, climatic tests and safety aspects for cabinets, racks, subracks and chassis as defined in the standards of the IEC 60917 series and the IEC 60297 series for indoor applications. Ensures physical integrity and environmental performance in cabinets, racks, subracks and chassis, taking into account the need for different levels of performance in different applications. Gives the user a level of confidence in the selection of performance levels to meet as close as possible the individual application requirements. Changes with respect to the previous edition include an extension of performance levels.