IEEE C57.105-2019 PDF
This guide describes transformer connections and configurations in three-phase electrical systems, the characteristics of these various connections, and the possible operating problems under normal or abnormal conditions. All combinations of delta and wye, grounded and ungrounded, T-connected, zigzag, and certain special connections are considered. Only two-winding and auto-transformers are included.
Revision Standard – Active. Descriptions of products, methods, and procedures relating to stationary batteries, battery electrolyte spill mechanisms, electrolyte containment and control methodologies, and firefighting considerations are provided.