Formulates specific safety rules for capacitor units and capacitor banks meant to be used connected in a series with a.c. transmission or distribution line or circuit forming part of an a.c. power system having a 15 Hz to 60 Hz frequency. Also formulates uniform rules regarding performance, testing and rating. Coverage includes service conditions, creepage distance, working current, transient overvoltages, container connection, markings of the unit, and choice of insulation level. Also gives definitions and annexes.