Practices by Discipline

​This Practice is a guideline for developing Overall Electrical One-Line Diagrams (OEOLDs) by engineers and designers. It covers the generation of new OEOLDs and may not apply to the revision of existing OEOLDs. This Practice applies to one-line diagrams that fit the definition of an OEOLD in Section 3. This Practice uses ANSI/IEEE 315 - IEEE Graphic Symbols for Electrical and Electronics Diagrams and IEEE C57.12.80 - IEEE Standard Terminology for Power and Distribution Transformer symbols. The guidelines in this Practice provide a balance between showing all data on OEOLDs and making OEOLDs legible and easy to read. Although this Practice describes major components in the electrical system, specific applications may require additional or alternative components. Determinations concerning fitness for purpose and matters of application of the Practice to a particular project or engineering situation should not be made solely on the information contained in this Practice. The OEOLD symbols included in the Appendices of this Practice are not intended to recommend specific design details or requirements. An example OEOLD is included to provide an illustration of how the elements of this Practice are combined into an OEOLD.​​