IEC TS 63493-1:2025 ED1

Transformer bushings dimensional standardization - Part 1: Medium voltage bushings with <em>U</em>_m from 12 kV up to and including 52 kV and <em>I</em>_r from 630 A up to and including 3 150 A

Scope

IEC TS 63493-1:2025 specifies the main parameters to facilitate interchangeability or at least to define some frame conditions of MV bushings:
- with Um from 12 kV up to and including 52 kV;
- Ir from 630 A up to and including 3 150 A.
This document deals with non-capacitance graded bushings for Power Transformers, according to the IEC 60076 series (usually for transformer with conservator).
In this document only liquid to air bushings are considered. Bushings of liquid-to-liquid and air-to-air type and bushings for transformers with air-cushion in tank are not considered.
MV is considered up to 52 kV; this value is used to cover specific insulation levels or for high pollution levels, even if the field of application is very restricted.
Both solutions with external insulation in porcelain and polymeric can be used and need to enable interchangeability (in terms of mechanical and electrical performance).