本指南涵盖了一次电压为601 V至52 kV时，在112.5 kVA或更大范围内降压操作的三相单元变电站。 本指南不包括以下安装: a） 变压器段被描述和定义为？网络，a？A.地铁，a？ A.保险库，a？还是一个？地下室？在IEEE标准C57中。12.24？？[B13]和IEEE标准C57。12.40？[B15]2 b） 变压器段被描述和定义为？pad mounteda？ c） 整流器- 类型变电站 d） 移动单元变电站 e） 船舶、船艇、铁路车辆、飞机或汽车上的装置 f） 矿山设施 g） 用于发电、变电、输电或配电的铁路设施 专用于机车车辆的运行，或专用于信号和 铁路通信目的 h） 由通信公司独家控制的通信设备的安装 公用设施，位于户外或专门用于此类安装的建筑空间内 i） 为通信目的由电力公司独家控制的装置，或 测量；或用于发电、控制、转换、传输和配电 位于建筑物内的能源，仅由公用设施用于此类目的，或位于室外 公用事业公司拥有或租赁的财产，或公共公路、街道、道路等上的财产。；或者在户外 私有财产的既定权利

This guide covers three-phase unit substations for step-down operation in the range of 112.5 kVA or greater at primary voltages of 601 V through 52 kV. This guide does not cover the following installations: a) Substations in which the transformer section is described and defined as "network," "subway," "vault," or "underground" in IEEE Std C57.12.24 [B13] and IEEE Std C57.12.40 [B15]2 b) Substations in which the transformer section is described and defined as "pad-mounted" c) Rectifier-type substations d) Mobile unit substations e) Installations in ships, watercraft, railway rolling stock, aircraft, or automotive vehicles f) Installations for mines g) Installations of railways for generation, transformation, transmission, or distribution of power used exclusively for operation of rolling stock, or for installations used exclusively for signaling and railway communication purposes h) Installations of communication equipment that is under the exclusive control of communication utilities, located outdoors or in building spaces used exclusively for such installations i) Installations under the exclusive control of electric utilities for the purpose of communication, or metering; or for the generation, control, transformation, transmission, and distribution of electric energy located in buildings used exclusively by utilities for such purposes or located outdoors on property owned or leased by the utility or on public highways, streets, roads, etc.; or outdoors by established rights on private property