States the characteristics of circuit breakers, the conditions with which they shall comply: (operation and behaviour in normal service, operation and behaviour in case of overload and operation and behaviour in case of short-circuit, dielectic properties), tests intended for confirming that these conditions have been met and the methods to be adopted for these tests, and information to be marked on or given with the appartus. The contents of the corrigendum of March 1997 have been included in this copy.