The Effect of Self-producing Heat and External Radiation on the Insulating Property of Wire

The effect of self-producing heat and external radiation on the insulating property of wire are studied experimentally in this paper. In the experiments of self-producing heat of wire, 6 types of wires are used under the situation of overloading. The results show that the effect of the temperature rise of wire on insulating property of wire is remarkable. Under the situation of having electric current wired to produce heat by itself, the insulation resistance of wire decreases and the leakage of electricity electric current enhances. Under the situation that electric current is relatively stable, the temperature becomes stable when rising to a certain value, conducting wire heat dissipating and fever heat are in an equilibrium state. In the experiments of external radiation, such as the situation of building fire, RV sheathed wires present a similar regulation to the self-producing heat experiments. The difference is that the effect of external factor (such as air flow, voltaic instability, etc.) on temperature of wire is more obvious than that on the insulation resistance of wire. When external factor makes the wire temperature decrease to a certain value, the insulation resistance value is higher than that out of the effect.