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ANSI/IEEE Std C57.12.56-1986 - IEEE Standard Test Procedure for Thermal Evaluation of Insulation Systems for Ventilated Dry-Type Power and Distribution Transformers

Description: This IEEE Standards product is part of the C57 family on Power Distribution and Regulating Transformers. A test procedure for determining the temperature classification of ventilated dry-type power and distribution transformer insulation systems by test rather than by chemical composition is established. The intent is to provide a uniform method for providing data for selection of the temperature classification of the insulation system, for providing data that may be used as a basis for a loading guide, and for comparative evaluation of different insulation systems. Voltage-withstand endpoint criteria are related to the impulse voltage distribution within the coil or to the initial voltage-withstand of the coil. A relationship between impulse withstand of the insulation and short-term 60-Hz-withstand is identified so that 50/60--Hz testing of model coils is possible.
  • Status:Superseded STDHelp

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