本标准旨在阐述与所述设备的性能、有限的电气和机械互换性以及安全性相关的特性，并帮助正确选择此类设备。 1.2本标准描述了某些电气和机械特性，并考虑了额定值为501 kVA及以上的60 Hz双绕组三相密封干式变压器的某些安全特性，这些变压器通常用于降压目的。 具体的额定值组合范围为750至5000 kVA（含），高压2400至34 500伏（含），低压208Y/120至4160伏（含）。 1.3本标准不适用于其他类型的变压器，如专用、通风干式、垫装干式、液浸式、仪表、调节、电炉、矿山和整流变压器。 1.4当本文件强制使用时，单词a？莎拉？表示强制性要求，以及

This standard is intended to set forth characteristics relating to performance, limited electrical and mechanical interchangeability, and safety of the equipment described, and to assist in the proper selection of such equipment. 1.2 This standard describes certain electrical and mechanical characteristics and takes into consideration certain safety features of 60-Hz, two-winding, three phase, sealed dry-type transformers rated 501 kVA and larger, generally used for step-down purposes. Specific rating combinations are described in the range from 750 to 5000 kVA inclusive, with high-voltage 2400 to 34 500 volts inclusive and low-voltage 208Y/120 to 4160 volts inclusive. 1.3 This standard does not apply to other types of transformers, such as specialty, ventilated dry-type, pad-mounted dry type, liquid immersed, instrument, regulating, furnace, mine, and rectifier transformers. 1.4 When this document is used on a mandatory basis, the word "shall" indicates mandatory requirements, and the words