IEEE - The Institute of Electrical and Electronics Engineers@ Inc.
Latest
IEEE 1C-1954
Scope
"Purpose. The chief purpose of this test code is to classify insulation systems in accordance with their temperature limits by test@ rather than by chemical composition. The intention is@ first@ to classify according to the recognized A@ B@ and H categories@ whose usual continuous hot-spot temperatures are 105@ 130@ and 180C@ respectively. Second@ to ascertain whether it is appropriate to change the present hot-spot temperatures for certain applications. It is not the intention at present to use this code to define any new or intermediate insulation temperature glasses. A wide variety of synthetic electrical insulating materials are available for application in electric machinery and apparatus. Included in these materials are the silicones@ fluorocarbons@ wire enamels@ and new films@ rubbers and varnishes. As there is a growing tendency to either rely solely on these materials as electrical insulation@ or to employ them with the old familiar materials in novel combinations@ there is a corresponding increase in the problems associated with the selection and evaluation of insulations. Frequently@ an insulation ""system"" or combination of insulation materials must be evaluated rather than one insulating ""material."" Many of the specifications regulating the use of insulation materials were written before the advent of the newer synthetics and were based upon experience gained with the old materials over a long period of time. Difficulties arise@ therefore@ when an effort is made to classify these materials or combinations for insulation purposes under the American Standards as Class A@ Class B@ or Class H insulation. The synthetic materials have widely varying properties@ so that it is not feasible to classify them on the basis of their chemical composition alone. Secondly@ it is not desirable to wait@ and acquire the knowledge required to classify them solely on the basis of experience. In the third place@ composite systems of insulation@ in which materials of different temperature classes are used in different parts of the structure@ may give satisfactory service at temperatures higher than normally permitted for the lowest temperature component; and@ conversely@ compatibility or other problems may arise whereby the highest temperature component is rendered unsuitable for use at its classified temperature. Recognizing this situation@ this test code has been prepared to outline useful procedures for insulation evaluation@ as a general guide to both temperature classification and the selection of insulation materials for application in random-wound rotating elcetric machinery. It is assumed that individual screening tests will eliminate all but the most desirable insulating materials@ which will then be evaluated in accordance with this test code. The code does not cover such special requirements as motors subjected to strong chemicals@ to metal dusts@ or to submersion in liquids."
IEEE 1C-1954 history
1954IEEE 1C-1954 Test Code for EVALUATION of SYSTEMS of INSULATING MATERIALS for RANDOM-WOUND ELECTRIC MACHINERY