IEEE 117-2015 pdf free download – IEEE Standard Test Procedure for Thermal Evaluation of Systems of Insulating Materials for Random- Wound AC Electric Machinery.
The intent of this procedure is to dlassify candidate jinsulation systems by comparing them. to reference_ insulation systems in machines with service-proven performance. Temperature lassification of insulation sytems are designated 105 °C. 130 °C. 155 °C 180 °C.200 “C, 220 °C 240 °C and above 240 °C, previously referred to as temperature casifications Class A. B. E H.N, R.S or C categories, respectively (sce Annex A for further information). It is expected that the several insulting materials or components that form. any insulation system to be evaluated by thee procedures will first be screened by the appropriate test procedures for each type of material. Thermal indices for discrete insulating materials can be obtained by following the procedures shown in IEEE Std 98T. Thermal indices of insulating materials cannot be used t classify insulation systems. They are to be considered only a5 screening tests for this system test.
1.4 Methods of evaluation
This test procedure descibes test models suitable for use in random-wound insulation tests. The procedure recommends a series of heat exposures to which the test models may be subjected to represent the cumulative effects of long service. using acelerated aging parameters. Procedures are given for applying periodic voltage schecks preceded by periods of mechanical stress and moisture te establish the end point of insulation life by eletric failure. To obtain an acceptable statistical average. for each chosen temperature of heat exposure. an adequate number of samples should be carried through the test procedure until failure occurs It is important that the tests on. the samples be performed a且minimum of three different aging fexposure) temperatures for each insulation system to be evaluated.
After the final results of the tests are known and the test life hours have been proiected t且rated temperature. the ratio of the aging. (exposure) hours of the candidate EIS compared to the aging (exposure) hours of the reference EIS can provide a rough measure of the service life expectangy of the candidate system in relation to that of the reference system. Based on the current state of the art in terms of test procedures, no accurate prediction of actual service life can be made from test results alone.
This procedure will permit approximate comparisons only. and cannot be relied upon to completely determine the merits of any particular insulation system. Such information can be obtained only from the experience of extended service. By following the general procedures utlined herein. the temperature cassification in which any candidate insulation system belongs can be determined.
2. Normative references
The following referenced documents are indispensable for the application of this document, icu they must be understood and used. For dated references. only the edition cited applies. For undated references. the Jlatest edition of the referenced document (induding any amendments or orrgenda) applies.IEEE 117 pdf download.