Resistance evaluation of electrical insulating polymer materials used in flexible cables to operational impact

Abstract

The article presents the test results of polymer material properties taking into account the possibility of their application for flexible cables insulation. The main types of cable constructions and their operation features are considered. Existing test determination methods of insulation resistance to thermal, mechanical, electrical and environmental conditions are analyzed. Requirements for laboratory equipment and test conditions are given. Evaluation criteria of test results are noted. Experimental evaluation was carried out for change degree in the properties of the main types of electrical insulation materials used currently during the flexible cable production: polyvinyl chloride compound (PVC), rubber, ethylene propylene rubber (EPR), thermoplastic elastomer (TPE), fluoropolymer. Tests were carried out under the influence of high and low temperatures, aggressive environments, ozone, mechanical loads. The main processes that determine the changes in electrophysical, physical and mechanical properties of the studied materials are described. Resistance of EPR, TPE and fluoropolymer insulation to a wide range of temperatures, mechanical loads, diesel fuel and transformer oil are shown. An increased resistance of EPR to ozone was also noted. Rubber and PVC compound did not pass the tests under the influence of low and high temperatures, showed "poor" resistance to aggressive environments, but passed the mechanical stress tests. Recommendations on tests and application of polymer insulation taking into account the specifics of flexible cables working are presented.