The following definitions are taken from the ANSI / IEEE Standard for Metal-Enclosed Bus C37.23-2003 and are the applicable definitions underpinning Crown Electric Engineering and Manufacturing LLC's product offering;
Per section 3.10 types of Metal Enclosed bus assemblies: In general, there are three basic types of construction used: Non-segregated phase, Segregated-phase, and Isolated-phase.
Non-segregated phase bus
One in which all phase conductors are in a common metal enclosure without barriers between the phases. When associated with metal-clad switchgear, the phase conductors of a non-insulated bus assembly entering the switchgear assembly and connecting to the switchgear bus shall be covered with insulating material equivalent to the switchgear insulation system.