New IEEE Standard - Superseded. Interpretations are available at: http://standards.ieee.org/reading/ieee/interp/C37.23-1987.html This IEEE Standards product is part of the C37 family on Switchgear, Substations and Protective Relays. Assemblies of metal-enclosed conductors and their associated interconnections, enclosures, supporting structures, switches, and disconnecting links are addressed. Ratings, tests, construction, miscellaneous accessories, and loss calculation for isolated-phase buses are covered. Specifically excluded are busways or bus assemblies for distribution of electric power less than 600 V, which consist of enclosed sectionalized prefabricated bus bars or associated structures and fittings, such as feeder busways (indoor or outdoor), plug-in busways (indoor only), and bus assemblies utilized at voltages in excess of 38.0 kV.