Applies to indoor capacitor units and indoor capacitor banks complete with accessories which are intended for connection to adjustable a.c. voltage systems, to operate in a frequency range from 40 to 24 000 Hz, for power factor correction, especially for inductive heating; and also for otherwise modifying the characteristics of a circuit, such as voltage and frequency. It applies to capacitors intended to be used at altitudes not exceeding 1000 m and within the prescribed temperature range of the cooling medium. This recommendation formulates safety rules and provides a guide for installation and operation. Note:For internal fuses and internal overpressure disconnectors for capacitors for inductive heat generating plants, see IEC 594.