IEC 61921-2017 PDF
Name in English:
St IEC 61921-2017
Name in Russian:
Ст IEC 61921-2017
Original standard IEC 61921-2017 in PDF full version. Additional info + preview on request
Full title and description
St IEC 61921-2017 — Power capacitors — Low-voltage power factor correction banks. This International Electrotechnical Commission (IEC) standard specifies requirements, verification and test provisions for low-voltage AC shunt capacitor banks intended for power factor correction, including banks that incorporate built-in switchgear and controlgear for connecting or disconnecting parts of the bank.
Abstract
The 2017 (2nd) edition of IEC 61921 updates and replaces the 2003 edition. It aligns verification methods with IEC 61439-1, modifies marking requirements, adds routine verification of rated output, includes a new Annex D with guidance on temperature-rise verification methods, updates normative references and implements a general editorial revision. The standard applies to low-voltage AC shunt capacitor banks used for power factor correction.
General information
- Status: Published / Current IEC edition (2nd edition).
- Publication date: 20 June 2017.
- Publisher: International Electrotechnical Commission (IEC); technical committee TC 33 (Power capacitors and their applications).
- ICS / categories: 31.060.70 (Power capacitors).
- Edition / version: Edition 2.0 (2017).
- Number of pages: 42 (official IEC publication; Redline variant available with additional pages).
General publication metadata is based on the IEC publication record for IEC 61921:2017.
Scope
IEC 61921:2017 applies to low-voltage AC shunt capacitor banks intended for power factor correction purposes, whether or not the banks include built-in switchgear and controlgear intended to connect or disconnect part(s) of the bank to/from the mains. Where applicable, such banks are expected to comply with requirements of IEC 61439-1 and IEC 61439-2. The edition replaces IEC 61921:2003 and provides updated verification, marking and temperature-rise guidance.
Key topics and requirements
- Definition and classification of low-voltage AC shunt capacitor banks for power factor correction.
- Requirements for banks incorporating built-in switchgear and controlgear (coordination with IEC 61439 series).
- Verification methods and routine tests, including addition of routine verification of rated output.
- Marking and documentation requirements for safe selection, installation and maintenance.
- Temperature-rise verification guidance (new Annex D) and associated test procedures.
- General editorial updates and updated normative references to reflect current practice.
These topics reflect the technical changes introduced in the 2017 edition and the standard's test/verification emphasis.
Typical use and users
IEC 61921 is used by manufacturers of power capacitor banks, switchgear and controlgear vendors, electrical design engineers, testing laboratories, utilities and industrial end-users specifying or verifying low-voltage power factor correction equipment. It is referenced when designing, specifying, testing and certifying capacitor bank assemblies and when ensuring compliance with related switchgear requirements.
Related standards
Directly related standards include the IEC 61439 series (IEC 61439-1 and IEC 61439-2) for low-voltage switchgear and controlgear assemblies; the 2017 edition supersedes IEC 61921:2003. National and regional adoptions (for example EN/EVS adoptions) exist, and a Redline (RLV) version of IEC 61921:2017 is available for change comparison.
Keywords
Power capacitors, capacitor banks, low-voltage, power factor correction, shunt capacitors, switchgear, controlgear, verification, temperature rise, routine test, IEC 61439.
FAQ
Q: What is this standard?
A: IEC 61921:2017 is an international standard that specifies requirements and verification methods for low-voltage AC shunt capacitor banks used for power factor correction, including guidance for banks with built-in switching and controlgear.
Q: What does it cover?
A: It covers classification, requirements, marking, routine and type verification methods, tests (including temperature-rise guidance in Annex D), and references coordination with the IEC 61439 series for assemblies that include switchgear/controlgear.
Q: Who typically uses it?
A: Manufacturers of capacitor banks and associated switchgear, electrical designers and specifiers, test laboratories, utilities and industrial maintenance teams use this standard to design, test and verify low-voltage power factor correction equipment.
Q: Is it current or superseded?
A: IEC 61921:2017 is the second edition published on 20 June 2017 and remains the current IEC edition; various regional adoptions and an EN/EVS adoption (EN IEC 61921:2025 in some regions) have been published or developed. Consult your national standards body for the applicable regional adoption and status.
Q: Is it part of a series?
A: The standard is maintained by IEC TC 33 (Power capacitors and their applications) and is related to other IEC standards addressing capacitor performance and low-voltage assembly requirements, particularly the IEC 61439 series for switchgear and controlgear assemblies.
Q: What are the key keywords?
A: Power capacitors; low-voltage capacitor banks; power factor correction; shunt capacitors; switchgear; controlgear; temperature rise; verification; routine tests.