Test procedures for the thermal evaluation of insulation systems for electric and electronic equipment should include introductory remarks necessary for a clear understanding of the objectives of the particular tests with respect to the industry served and of the special requirements that exist. If any different or new concepts of insulation behavior@ or use@ are embodied in a Test Procedure@ they should be clearly stated. Technical Committees should attempt to assure that each Test Procedure: (a) gives statistically consistent results@ (b) provides data free from bias of the tester@ (c) includes@ if models are used@ results of these models representative of the equipment (the equipment itself may be evaluated where feasible)@ (d) results in information that correlates with field experience in a satisfactory manner. PURPOSE It is the responsibility of IEEE Technical Committees to prepare functional Test Procedures for the thermal evaluation and classification of the insulation systems used in electric equipment. These Test Procedures involve accelerated thermal aging based on conditions of use and specify tests that the Committees deem pertinent. The objective of these Test Procedures is to provide for the classification of insulation systems for electric equipment in accordance with their temperature limits by test rather than by chemical composition of the component materials of the system. It is recognized that a given insulation system may be used under different conditions of temperature@ time@ voltage@ etc. Therefore@ the evaluation of an insulation system involves all of the various parameters of application and use of equipment but not the evaluation of separate component materials. The evaluation of insulating materials and simple combinations thereof is provided for by separate material Test Procedures. It is the purpose of this Guide to provide a general form for the preparation of systems Test Procedures and to suggest the points to be considered by the Technical Committees in the preparation of specific instructions for the thermal evaluation of insulation systems for equipment. For a detailed discussion of the principles on which this Guide is based@ see IEEE Standards Publication No. 1.