A growth process of hot-zone generated by high-frequency current

A phenomenon which raises the temperature at the electrical connection and electrical contact point of electric wires is investigated. When a large electric current flows in the electric wire connections, the temperature of the section rises and subsequently causes an electric fire. The area of the high temperature is small, but it can become as high as 1000°C. We have named it the "hot-zone phenomenon" and observed the growth process. The electrical characteristics of the hot-zone generated by current were measured for copper wire supplied with high-frequency voltage and current waveform. The formation processes of cuprous oxide in the connection were also studied. A triangular wave was used for the experiment. The area of the hot-zone was changed by heating the connection point. It was observed that the high temperature area was limited. The growth of the hot-zone and formation of the cuprous oxide by hot-zone was controlled by heating or adding bias voltage.