Includes the characteristics of cables with single copper conductors, for use at a nominal voltage of 6OO V, a maximum frequency of 2 OOO Hz and a continuous temperature not exceeding 28O °C (ambient temperature plus heating) but which may withstand 4OO °C for a limited period. The cables will retain a certain amount of dielectric strength when subjected to a flame of 1 1OO °C for 5 min.