This guide applies to station service systems that supply electric power to auxiliary loads for electric power generating stations. The discussions and recommendations in this guide provide the practices, criteria, and range of system parameters that relate to the service system requirements and assist in the application of existing engineering documents. This guide is not a handbook of design data; however, it explains what is good practice for the many different types of electric power service systems for generating stations.

While this design guide applies to all types of power generating stations, it is particularly applicable to stations in which the electric power service system is required to perform continuously. When electric power for auxiliary loads is supplied from the power grid, the service system begins at the point where the tap from the power grid terminates, either at a station service bus or at the terminals of the transformer that supplies the bus. When service to auxiliary loads is from independent generators or electric storage batteries that are not normally operated as power supplies to the power grid, the station service system includes the generators and s...

The purpose of this revision is to update the guide in general, including: 1. General update of references and correction of typo errors, and review the impact of the latest revisions of other standards on this document; 2. Evaluate and consider expanding the level of details in the guide; 3. Address comments received since the guide was published in 1991; 4. Add clarifying text where indentified to be needed; 5. Expand information in sections where more state of the art data is available.