scope:

This guide covers the application, specification, theory of operation, and factory and field testing of singlephase and three-phase oil-immersed phase-shifting transformers (PSTs). This guide is limited to matters particular to PSTs and does not include matters relating to general requirements for power transformers covered in existing standards, recommended practices, or guides. The terminology, function, application, theory of operation and protection, and design of PSTs are not covered by existing transformer standards and guides. The purpose of this document is to provide guidance to those specifying, designing, and using PSTs.