Characteristics of the insulation resistance of the cable according to high temperature environment and temperature increase in the melting furnace process

Abstract

In this study, the process environment temperature and insulation resistance were measured through the investigation on actual condition on cables of 2.5㎟ for Oil Pump #A, 6㎟ for Oil Pump #B, and 10㎟ for Heater CV, which are exposed to high temperature environments among the eight melting furnace processes. Based on this, the experiment was conducted in a facility that simulated the high temperature conditions in the process, and the effect of high temperature on insulation resistance was analyzed using the Arrhenius equation. Oil Pump #A showed a maximum temperature of 105 °C when the melting furnace was in operation, and 70 °C when it was stopped. Additionally, the insulation resistance maintained 100㏁ for up to 7 years, but then showed a rapid decrease of 50% to 50㏁ after one year. The experiments based on the actual condition and the application of the Arrhenius equation indicated that the insulation resistance decreased sharply at 80 °C, with the Arrhenius equation showing similar results. Therefore, applying the Arrhenius equation presented in this study can predict the insulation resistance of cables in high-temperature environments, thus preventing cable fires in places where it is difficult to measure and manage insulation resistance due to a high temperature environment.