American standard bushing for single-phase transformers

There is no single international standard for single-phase transformer bushing, but multiple American National Standards (ANSI) and Institute of Electrical and Electronics Engineers (IEEE) standards share common specifications. The following are some relevant standards:

ANSI/IEEE C57.12.00: This standard specifies the electrical, mechanical, and safety requirements for oil immersed distribution, power, and regulating transformers. 

It serves as the basis for establishing equipment performance, limited electrical and mechanical interchangeability, and safety requirements, and is also the basis for

 selecting such equipment. It involves some general requirements for transformer bushings.

ANSI C57.12.22-1993: The standard covers certain electrical, dimensional, and mechanical characteristics of three-phase, 60Hz, mineral oil immersed, self cooled, base

 mounted, and room type distribution transformers with rated power of 2500kVA and below, high voltage of 34500GrdY/19920V and below, and low voltage of 480V and 

below, taking into account safety features, including the arrangement of bushings and terminals for radial feeding systems.

IEEE C57.12.70-2020: This standard specifies the standard terminal marking and connection methods for single-phase and three-phase distribution, power, and 

regulating transformers, including the sequence designation of terminal marking, external terminal designation, neutral terminal designation, grounding terminal 

designation, and marking of full winding and tap winding terminals. It provides guidance for the connection of transformer bushings and other aspects.

ANSI/IEEE C57.12.90: This standard specifies the temperature rise and other aspects of transformer windings, and the performance of the bushing is closely related to

 the temperature rise and other parameters of the transformer. For example, the transformer standard in American Samoa mentions that according to the latest version of ANSI C57.12.90, when measured by resistance method at rated voltage and kilovolt ampere, the temperature rise of the transformer winding should not exceed 65 ℃, and the hot spot temperature rise should not exceed 80 ℃.