IEC 62271-201:2014 specifies requirements for prefabricated solid-insulation enclosed switchgear and controlgear for alternating current of rated voltages above 1 kV and up to and including 52 kV for indoor installation and for service frequencies up to and including 60 Hz. This second edition cancels and replaces the first edition, published in 2006. This edition constitutes a technical revision. This edition includes the following significant technical changes with respect to the previous edition: a) apart from updating with the second edition of IEC 62271-200 (issued in 2011), definitions, classifications and testing procedures have been specified more precisely; b) access to the solid-insulation enclosed switchgear and controlgear is now restricted to authorized personnel only. This implies that 'accessibility class B' (public access) has been deleted throughout the document; c) the term 'protection category' has been introduced to replace the term 'protection grade' (PA, PB1 and PB2).