NEW! IEC 60831-1:2014 is available as IEC Standards+ 60831-1:2014 which contains the International Standard and its Redline version, showing all changes of the technical content compared to the previous edition. IEC 60831-1:2014 is applicable to both capacitor units and capacitor bank s intended to be used, particularly, for power-factor correction of a.c. power systems having a rated voltage up to and including 1 000 V and frequencies of 15 Hz to 60 Hz. This part of IEC 60831 also applies to capacitors intended for use in power filter circuit s. Additional definitions, requirements, and tests for power filter capacitors are given in Annex A. The object of this part of IEC 60831 is to: - formulate uniform rules regarding performances, testing and rating; - formulate specific safety rules; - provide a guide for installation and operation. This third edition cancels and replaces the second edition published in 1996 and Amendment 1:2002. This edition constitutes a technical revision. This edition includes the following significant technical changes with respect to the previous edition: - Updating of the normative references; - Test conditions have been clarified; - Thermal stability test has been clarified; - Maximum permissible voltage and current have been clarified; - The protection of the environment has been amended with safety concerns and plastic quality requirements. Keywords: capacitor units and capacitor banks, uniform rules regarding performances, testing and rating; safety rules; guide for installation and operation