Revision Standard - Active.IEEE Std C37.23-2003 is a revision of IEEE Std C37.23-1987 (Reaff 1991). Project scope: This standard covers assemblies of metal-enclosed conductors along with associated interconnections, enclosures, and supporting structures. When switches and disconnecting links are included, they shall conform to this standard. This standard is concerned with performance characteristics of enclosed, rather than open, indoor and outdoor conductor assemblies with rated maximum operating voltages through 38 kV. While this standard does cover 600 volt assemblies, it does not pertain to ANSI/UL 857 type busways and associated fittings, nor does it pertain to metal enclosed bus assemblies utilizing cables as the primary conductors. Project purpose: The Standard for Metal-Enclosed Bus was last updated in 1987. The standard needs to be updated to harmonize with certain other standards within the C37.2XXX series of documents.