Short-circuit ratings for mains cables

Research work carried out by the E.R.A. has enabled distribution engineers to assess with greater accuracy the strength of paper- (or cambric-) insulated cables to resist the forces arising from severe short-circuits. E.R.A. Report Ref. F/T195 describes the research work which has been carried out over a number of years; the present paper interprets the results of the research and provides curves which illustrate the short-circuit currents which can be safely carried by such cables at working voltages up to 11 kV.