Study for the Effect of Fireproof Tapes on Temperature Monitoring and Ampacity of High Voltage Cable

This paper constructs a 220KV cable ampacity verification platform to evaluate the effect of fireproof tapes on cable ampacity and temperature. According to the experiments and theoretical analysis, it can be found that the heat dissipation of rubber fireproof tapes is the best, and the performance of PVC material is inferior to rubber ones. Both of rubber and PVC fireproof tapes are far superior to that of ceramic fiber on heat dissipation. The maximum allowable ampacity of high voltage cable will be reduced by wrapping fireproof tapes. The cable ampacity of ceramic fiber, PVC, and rubber fireproof tapes are 81.9%, 96.2%, and 96.4% of the non-wrapping cable, respectively. When cables reach the maximum allowable ampacity, the surface temperature of ceramic fiber, PVC, and rubber fireproof tapes are 38.7 °C, 52.7 °C and 52.9 °C, respectively, which are lower than the maximum allowable temperature of 55 °C for non-wrapping cables. Therefore, the alarm threshold should be reduced in the temperature measuring system of distributed optical fiber, in order to ensure the cable core temperature does not exceed 90 °C under the maximum current ampacity.