This part of IEC 60143 applies both to capacitor units and capacitor banks intended to be used connected in series with an a.c. transmission or distribution line or circuit forming part of an a.c. power system having a frequency of 15 Hz to 60 Hz. The primary focus of this standard is on transmission application. The series capacitor units and banks are usually intended for high-voltage power systems. This standard is applicable to the complete voltage range. This standard does not apply to capacitors of the self-healing metallized dielectric type. The following capacitors, even if connected in series with a circuit, are excluded from this standard: capacitors for inductive heat-generating plants (IEC 60110-1); capacitors for motor applications and the like (IEC 60252 (all parts)); capacitors to be used in power electronics circuits (IEC 61071); capacitors for discharge lamps (IEC 61048 and IEC 61049). For standard types of accessories such as insulators, switches, instrument transformers, external fuses, etc. see the pertinent IEC standard. NOTE 1 Additional requirements for capacitors to be protected by internal fuses, as well as the requirements for internal fuses, are found in IEC 60143-3. See also Annex C. NOTE 2 Additional requirements for capacitors to be protected by external fuses, as well as the requirements for external fuses, are found in Annex A and Annex C. NOTE 3 A separate standard for series capacitor accessories (spark-gaps, varistors, discharge reactors, current- limiting damping reactors, damping resistors, circuit-breakers, etc.), IEC 60143-2, has been revised and was completed in 2012. A separate standard for internal fuses for series capacitors, IEC 60143-3 has been revised and was completed in 2013. NOTE 4 Some information regarding fuseless capacitor units and fuseless capacitor banks is found in Annex C. The object of this standard is; to formulate uniform rules regarding performance, testing and rating; to formulate specific safety rules; to serve as a guide for installation and operation.