scope:

This technical report is applicable to alternating current and direct current bushings for rated voltages above 52 kV, mounted on transformers, other apparatus or buildings. It is accepted that for bushings for rated voltages less than or equal to 52 kV, due to their characteristics (resonance frequency greater than 25 Hz) seismic qualification is not required. This technical specification presents acceptable seismic qualification methods and requirements to demonstrate that a bushing can maintain its mechanical properties, insulate and carry current during and after an earthquake. The seismic qualification of a bushing is only performed upon request.