IEC 60137:2017 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;
• 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 par t.
