The Short-Circuit Rating of Thin Metal Tape Cable Shields

It is pointed out that conventional methods of calculating the short-circuit ratings of cable conductors can lead to gross errors in the case of the thin metal tape shields commonly used in plastic-insulated cables. A more rigorous treatment of the problem is developed for both single and repeated short circuits. The theoretical calculations are compared with the results of a series of practical tests on two types of 15-kV polyethylene-insulated cable and with other test data available to the authors. Substantial agreement is found.