High-voltage switchgear and controlgear - Part 202: AC prefabricated substations for rated voltages above 1 kV and up to and including 52 kV

This part of IEC 62271 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. These prefabricated substations can be situated at ground level or partially or completely below ground level. The last are also called "underground prefabricated substations". In general, two types of prefabricated substations are considered in this document: – high-voltage switchgear prefabricated substations; – high-voltage/low-voltage transformer prefabricated substations (step-up and step-down). A high-voltage switchgear prefabricated substation comprises an enclosure containing in general the following electrical components: – high-voltage switchgear and controlgear; – auxiliary equipment and circuits. A high-voltage/low-voltage transformer prefabricated substation comprises an enclosure containing in general the following electrical components: – power transformer(s); – high-voltage and low-voltage switchgear and controlgear; – high-voltage and low-voltage interconnections; – auxiliary equipment and circuits. However, relevant provisions of this document are applicable to designs where not all these electrical components exist (for example, a prefabricated substation consisting of power transformer and low-voltage switchgear and controlgear