IEEE C57.12.56-1986 pdf download.IEEE Standard Test Procedure for Thermal Evaluation of Insulation Systems for Ventilated Dry-Type Power and Distribution Transformers.
IEEE C57.12.56-1986 is intended to establish a uniform method for determining the temperature classification of ventilated dry-type power and distribution transformer insulation systems by test rather than by chemical composition.
These insulation systems are intended for use in transformers listed in ANSI C57. 12.50-1981and ANSI C57.12.51-1981,and whose highest voltages exceed nominal 600 V.
NOTE – In this standard, the term transformer shall be considered to mean ventilated dry-type transformer unless qualified by other descriptive terms.
1.2 Purpose
The purpose of IEEE C57.12.56-1986 is to establish a uniform method:
1) For providing data for selection of the temperature classification of the insulation system.
2) For providing data which may be used as a basis for a loading guide.
3) For comparative evaluation of different insulation systems.
2.1 General
Two test methods are developed to provide a means for evaluating insulation systems as a function of thermal aging and are an extension of AlEE 65-1956 Thermal Evaluation of Ventilated Dry-Type Power and Distribution Transformers.
method is based on retention of a dielectric withstand voltage equal to a percentage of the initial 50/60 Hz dielectric withstand c capability of the test sample.
The second method is based on the retention of the basic impulse insulation level by impulse testing, or by related [10]50/60 Hz voltage withstand capability tests on models. See 3.7.
2.2 Intent
The intent of these test methods is to have each component of the insulation system tested under conditions that are as nearly as possible the same as those in the actual transformer. Thus, each of the components is evaluated in accordance with its actual function.IEEE C57.12.56-1986 pdf download.
IEEE C57.12.56-1986 pdf download
PS:Thank you for your support!
