Transmission Substation – Breaker/Relay Improvements

David Mason + Associates (DMA) worked as a subconsultant to Burns & McDonnell on a 345kV/138kV substation. The 345kV Line and associated breaker were both upgraded as part of this project.

The line upgrades included replacing existing electromechanical relays with microprocessor relays for improved line protection. The line protection was also modified to incorporate DTT and POTT schemes. The breaker upgrades included the installation of new breaker failure and lockout relays, as well as improved metering capabilities.

DMA provided updated drawings, bill of materials, and construction release documentation. The protection and control drawing package included One-Line Diagrams, Three-Line Diagrams, Schematics, Panel Elevations and Layouts, and Wiring Diagrams. The physical drawing package included General Arrangements, Conduit and Grounding Plans, Control Building Layout, and Conduit and Grounding Details.

This substation was not up to the Owner’s design standards for many of the drawings, nameplates, and naming conventions of certain equipment. There were also multiple errors in the protection specifications that had a direct impact on the project design. DMA was able to not only design in accordance with the standards, but also assist in updating much of the legacy information to the current standards.