scope:

This standard covers assemblies of metal-enclosed (ME) 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 V bus assemblies, it does not pertain to UL 857-2001 type busways and associated fittings, nor does it pertain to ME bus assemblies utilizing cables as the primary conductors.