Low-voltage switchgear and controlgear assemblies - Part 6: Busbar trunking systems (busways)
IEC · IEC TC 121
Product standard for low-voltage busbar trunking systems (busways), widely used for overhead rack power in data halls.
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Overview
IEC 61439-6 is the product part of the low-voltage switchgear and controlgear assemblies series devoted to busbar trunking systems (BTS, busways). It covers definitions, service conditions, construction requirements, technical characteristics and verification requirements for systems widely used for overhead rack power in data halls. It applies to BTS with a rated voltage not exceeding 1 000 V AC or 1 500 V DC.
Edition 1 was published on 23 May 2012, runs to 85 pages and cancels and replaces IEC 60439-2:2000 and its 2005 Amendment 1. It corrected inconsistencies in the resistance, reactance and impedance measurements and calculations. Edition 2 (IEC 61439-6:2026) is offered as an FDIS pre-release, with voting from 16 October to 27 November 2026, so the new edition is not yet in force.
Related documents are IEC 61439-1, IEC 60364-5-52 and TS EN 61439-6. The record gives no rated-current or withstand values; these must be taken from the manufacturer's catalogue and verification documents.
Key points
- Applies to BTS with rated voltage not exceeding 1 000 V AC or 1 500 V DC.
- Covers definitions, service conditions, construction, technical characteristics and verification requirements.
- Cancels and replaces IEC 60439-2:2000 and its Amendment 1 (2005).
- Corrected inconsistencies in resistance, reactance and impedance measurements and calculations.
- Edition 2 (IEC 61439-6:2026) offered as FDIS pre-release; voting 16 October to 27 November 2026.
- Edition 1 published 23 May 2012; 85 pages.
- Related standards: IEC 61439-1, IEC 60364-5-52, TS EN 61439-6.
Using it in design
- In the busway object, catalogue rated current, Icw, R/X per metre, tap-off ratings and IP class.
- Use the impedance data in the short-circuit and voltage-drop calculators.
- Note the pending 2026 edition in the standards register.
- Attach the manufacturer's verification documents for the selected BTS to the project file.
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Who should read it
Electrical engineers selecting overhead busways and performing short-circuit and voltage-drop calculations.
Related standards
- IEC 61439-1
- IEC 60364-5-52
- TS EN 61439-6
Publication details
- Authors
- IEC TC 121
- Publisher
- IEC
- Year
- 2012
- Document number
- IEC 61439-6:2012
- Document language
- English
- Source type
- Standard
- Access
- Citation only
- Licence
- Copyright retained; citation only — the publisher’s terms apply to the original document
Original licence note
Paid standard. Record built only from the publisher's public catalogue abstract and product metadata; full text not redistributed.
Citation
IEC TC 121 (2012). Low-voltage switchgear and controlgear assemblies - Part 6: Busbar trunking systems (busways). IEC. IEC 61439-6:2012. https://webstore.iec.ch/en/publication/5463
Events on this subject
- Electricity Eurasia 2027
- ELECO 2026 Elektrik-Elektronik ve Biyomedikal Mühendisliği Konferansı
- NVIDIA GTC
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