Busbar book - Continuing a tradition since 1936

Busbars are used within electrical installations for distributing power from a supply point to a number of output circuits.  They may be used in a variety of configurations ranging from vertical risers – carrying current to each floor of a multi-storey building – to bars used entirely within a distribution panel or within an industrial process.

This publication describes the main issues that need to be addressed in the design of busbar systems, such as temperature rise due to energy losses; energy efficiency and lifetime cost; short-circuit current stresses and protection; jointing methods and performance; and maintenance.

Copper Development Association first published the popular ‘Copper Busbars: Guidance for Design and Installation’ in 1936. The current edition adds significant content on busbar profiles and simplified formulae for busbar configurations.  It is of particular benefit to design engineers of electrical distribution systems seeking to design efficient, economic and reliable busbar systems.

108 pages in length and available for free download, Copper Busbars is divided into six chapters.  The introductory chapter focuses on materials for busbars, detailing the properties of a conductor material that are essential to achieve a long and reliable service life at the lowest lifetime cost.  It reviews conductor materials for busbars and concludes that the required combination of properties is a very good match for copper.

The book includes a completely-revised chapter on current-carrying capacity.  Original work performed for the book allowed to greatly simplify the calculation of current-carrying capacity of busbars by providing exact formulae for some common busbar configurations, and graphical methods for others. This should be of great help to designers in calculating ratings for their busbar systems.

The book also features a brand new chapter on profiles.  This content was added because busbar profiles are seeing increasingly use in distribution panels and switchboards, but the design considerations for this application are significantly different from long vertical and horizontal busbars.  It is a growing market since busbar profiles offer distinct advantages, such as material savings, lower assembly time, lower complexity and reduced scrap.

Other chapters cover lifecycle costing, short-circuit effects and jointing techniques for busbars.  An annex provides valuable information on busbar coatings, focusing on the reasons for coating them, methods of coating, inspection and maintenance.

If you've read the busbar book, we welcome your feedback through this survey (11 questions).

Update February 2, 2016: A few errors have been overlooked in our editorial processes. A list of corrigenda has been added.


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Manas Kundu's picture

Please see following comment that may be taken into account in next  version update.


Pascal de Vilder


New Website Contact on GPG - Copper Busbar Design Guide


Dear sir/madam, I recently used your resource "copper for busbars". As I got very different results using the formula for K in the chapter "Proximity factor" compared to using the graph, I started digging. Using the article by Dwight found in Electrical World vol. 70 (p. 523), I found out (-b^3)/3 should be (-b^2)/3. I hope you'll edit this, so people will use the correct formula when trying to calculate this. With regards, Pascal


By Manas Kundu 01/12/2014
webmaster's picture

Your comment refers to an old edition of the busbar book. It should not affect the latest edition on this page. Please replace your page with the current edition.

By webmaster 08/12/2014


  • The technical requirements for busbars match well with the material properties of copper
  • Calculating the current carrying capacity can be simplified by using common busbar configurations and graphical methods
  • Well-chose busbar profiles can save material, reduce complexity, reduce assembly time, as well as the amount of scrap
  • The quality of joints is crucial to the long term reliability of a busbar system, and can be assessed through thermal imaging