This International Standard specifies the characteristics and tests for insulated bushings.This standard is applicable to bushings@ as defined in Clause 3@ intended for use in electrical apparatus@ machinery@ transformers@ switchgear and installations for three-phase alternating current systems@ having highest voltage for equipment above 1 000 V and power frequencies of 15 Hz up to and including 60 Hz.Subject to special agreement between purchaser and supplier@ this standard may be applied@ in part or as a whole@ to the following: ? bushings used in other than three-phase systems;? bushings for high-voltage@ direct current systems;? bushings for testing transformers;? terminals for power cables (potheads);? bushings for capacitors.Special requirements and tests for transformer bushings in this standard apply also to reactor bushings.This standard is applicable to bushings made and sold separately. Bushings which are a part of an apparatus and which cannot be tested according to this standard@ should be tested with the apparatus of which they form part.