IEC 62271-202:2022 specifies the service conditions, rated characteristics, general structural requirements and test methods of enclosed high-voltage prefabricated substations. These prefabricated substations are cable-connected to AC high-voltage networks with an operating voltage up to and including 52 kV and power frequencies up to and including 60 Hz. They can be manually operated from inside (walk-in type) or from outside (non-walk-in type). They are designed for outdoor installation at locations with public accessibility and where protection of personnel is provided.
This third edition cancels and replaces the second edition published in 2014. This edition constitutes a technical revision.
This edition includes the following significant technical changes with respect to the previous edition:

1. the whole document contents and structure are reviewed with due consideration of IEC 62271-1:2017;
2. modification of the title and scope to include high-voltage switchgear prefabricated substations;
3. inclusion of CEADS as a possible component of MV/LV prefabricated substation;
4. in 7.2.101, the possible influence of surrounding elements on the dielectric performance of high-voltage components as high-voltage switchgear and controlgear and high-voltage interconnections non-metal-enclosed or without earthed screen are now considered;
5. new informative Annex G with testing procedure to evaluate the impact of solar radiation in temperatures inside the enclosure and how to apply it;
6. new informative Annex H for appropriate consideration of installation conditions of electronic equipment;
7. the rated power of a prefabricated substation is now defined as a three-parameter rated value. See 5.101.1;
8. minimum dimensions for access doors to the prefabricated substation in 6.104.4 and for free height of operation aisle in 6.105.3 have been introduced;
9. continuous current (temperature rise) test methods have been revised/clarified where necessary;
10. Figure D.1, which shows the mineral-oil-immersed power transformer load factor inside the enclosure, has been corrected.