IEC 60840:2011 is available as IEC 60840:2011 RLV which contains the International Standard and its Redline version, showing all changes of the technical content compared to the previous edition. IEC 60840:2011 specifies test methods and requirements for power cable systems, cables alone and accessories alone, for fixed installations and for rated voltages above 30 kV (Um = 36 kV) up to and including 150 kV (Um = 170 kV). The requirements apply to single-core cables and to individually screened three-core cables and to their accessories for usual conditions of installation and operation, but not to special cables and their accessories, such as submarine cables, for which modifications to the standard tests may be necessary or special test conditions may need to be devised. This standard does not cover transition joints between cables with extruded insulation and paper insulated cables. The significant technical change with respect to the previous edition is as follows: - introduction of a prequalification test procedure for cables with high electrical stresses and tested as a cable system including accessories. NOTE: For a more detailed history of events leading up to this fourth edition, see the Introduction.