Evaluation of pyrolysis and arc tracking on candidate wire insulation designs for space applications

Polyimide wire insulation has been found to be vulnerable to pyrolization and arc tracking due to momentary short-circuit arcing events. This report compares arc tracking susceptibility of candidate insulation configurations for space wiring applications. The insulation types studied in this report were gauge 20 hybrid wiring constructions using polyimide, tetrafluoroethylene (TFE), Cross-linked Ethylene Tetrafluoroethylene (XL-ETFE) and/or polytetrafluoroethylene (PTFE) insulations. These constructions were manufactured according to military wiring standards for aerospace applications. Arc track testing was conducted under DC bias and vacuum (10/sup -6/ torr). The tests were conducted to compare the various insulation constructions in terms of their resistance to arc tracking restrike. The results will be presented and discussed in this paper.<>