Life Characteristics of Medium Size Insulated Wire Subjected to Short Time, High Current Faults

This paper continues the study of damage done to insulated wire by high currents which occur during the brief time necessary for protective devices to clear a bolted short circuit. The damage was measured by the decrease in dielectric strength related to various values of the time integral of the square of the current. This is called I2t. One major advantage of this approach is the definiteness with which significant damage is identified. The data reported here when combined with the data of the previous paper shows a linear relationship between the logarithm of I2t and cross sections of the most used building wires.