本标准涵盖金属封闭（ME）导体组件以及相关互连、外壳和支撑结构。所涵盖的组件类型包括非隔离相母线、隔离相母线、隔离相母线和电缆母线。当包括开关和隔离开关时，它们应符合本标准。本标准包括额定最大工作电压为38 kV的室内和室外导线组件的性能特征。本标准不适用于UL 857[B22]型母线槽和相关配件。确定了绝缘材料的使用条件、额定值、温度限制和分类、绝缘（电介质）耐受电压要求、试验程序和应用。 包括计算离相母线损耗的指南。

This standard covers assemblies of metal-enclosed (ME) conductors along with associated interconnections, enclosures, and supporting structures. The types of assemblies covered are nonsegregated-phase bus, segregated-phase bus, isolated-phase bus, and cable bus. When switches and disconnecting links are included, they shall conform to this standard. This standard encompasses the performance characteristics of indoor and outdoor conductor assemblies with rated maximum operating voltages through 38 kV. This standard does not pertain to UL 857 [B22] type busways and associated fittings. Service conditions, ratings, temperature limitations, and classification of insulating materials, insulation (dielectric) withstand voltage requirements, test procedures, and applications are established. A guide for calculating losses in isolated-phase bus is included.