1 Scope
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: