Recommended Practice for Thermal Evaluation of Insulation Systems for Alternating-Current Electric Machinery Employing Form-Wound Preinsulated Stator Coils for Machines Rated 6900 V and Below
This standard outlines a test procedure for comparing two or more insulation systems in accordance with their expected life at rated temperature. The procedure is limited to insulation systems for ac electric machines using formwound preinsulated stator coils and rated 6900 V and below. It is the intent of this procedure to evaluate insulation systems for use in usual service conditions with air cooling. It does not cover such special requirements as machines that are enclosed in gas atmospheres@ or that are subjected to strong chemicals@ to metal dusts@ or to submersion in liquids@ etc. The procedure includes instructions for testing candidate systems in comparison with known systems having a proven record of service experience and interpretation of the results. Purpose The purpose of this procedure is to classify insulation systems for the machinery within the scope of this standard in accordance with their temperature limits by test@ rather than by chemical composition. Data from such tests may be used to establish the temperature classi?cation of new insulation systems before they are service proven. Service-proven systems shall also be tested according to this test procedure.