IEEE 117-2015 pdf free.IEEE Standard Test Procedure for Thermal Evaluation of Systems of Insulating Materials for Random-Wound AC Electric Machinery.
This is a standard test predure for the thermal evaluation and qualification of electrical insulation systems (EISs) for random-wound ac electric machinery, where thermal degradation is the dominating aging factor. This procedure compares the relative thermal performance of a candidate EIS to that of a reference EIS. This standard covers insulation systems for such machinery with operating voltage of up to 600 V at 50/60 Hz. This standard provides a statistical method for establishing a relative life-temperature relationship for an insulation system. To have any significance, the reference insulation system must be supported with adequate field-service data. This procedure is intended to evaluate insulation systems for use in air-cooled, random-wound ac electric machinery with “usual service conditions.” This procedure. on its own, does not cover insulation systems such as exposure to conducting contaminates, radiation, inverter applications, or operation in oils, refrigerants, or other media that potentially degrade insulating materials.
The intent of this procedure is to classify candidate insulation systems by comparing them to reference insulation systems in machines with serice.provcn rformance. Temrature classification of insulation systems arc designated 105 °C. 130 °C. 155 °C, 180 °C, 200 °C, 220 °C. 240 ‘C. and above 240 C. previously referred to as temrature classifications Class A, B, F. II. N, R. S or C categories, respectively (see Annex A for further information). It is expected that the several insulating materials or components that form any insulation system to he evaluated by these procedures will first be screened by the appropriate test procedures for each type of material. Thermal indices for discrete insuIatin materials can he obtained by following the procedures shown in IEEE Std 98.
This test procedure describes 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 accelerated aging parameters. Procedures are given for applying periodic voltage checks preceded by periods of mechanical stress and moisture to establish the end point of insulation life by electric 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 at a minimum of three different aging (exposure) temperatures for each insulation system to be evaluated.IEEE 117 pdf download.