Short-circuit capacity of temporary grounding cables

Theoretical development and experimental verification of a computer program for generating high-current short-duration failure characteristics of personnel grounding cables are presented. The program is structured for use in power systems applications and is incorporated in a user-friendly shell designed to run on IBM-PC-compatible computers. The computer model is based on an approach which relates the temperature rise of a cable to the time integral of current density. The analytical derivation on which the model is based allows for prediction of cable failure characteristics not only for symmetrical, but also for asymmetrical currents. To generate a statistically valid database for checking the accuracy of the model, several hundred tests were carried out on cables varying in size from 1/0 to 250 MCM with current magnitudes ranging between 17 kA and 80 kA. Analysis of the data obtained from these tests shows that the failure characteristics predicted using the model agree well with those determined experimentally.< >