Case Study: City of Mesa achieves a flexible, lower-cost substation automation upgrade with Schweitzer Engineering Laboratories (SEL)

Efficiently Replace PLC Automation Systems by Integrating IEDs With Fiber-Optic and Ethernet Communications in the Substation

City of Mesa needed to modernize its substation integration and automation as it expanded and upgraded its electric system, but its existing PLC-based design was costly, wiring-intensive, hard to expand, and difficult to support. The utility wanted a way to add a new substation bay without disrupting live operations, preserve existing SCADA screens and data maps, improve communications, and enable remote access to substation IEDs. Schweitzer Engineering Laboratories (SEL) provided the protection, communications processor, I/O processor, meters, and related communications equipment used in the new design.

SEL helped City of Mesa replace the PLC-centric architecture with an integrated IED-based solution using serial and Ethernet communications, fiber-optic networking, and serial tunneling over Ethernet. The new system eliminated the PLC, interposing relays, and much of the discrete I/O wiring, while enabling remote SCADA control, engineering access, and better support for future expansion such as DNP LAN/WAN and sequence-of-events recording. The result was a simpler, lower-cost, more flexible substation platform that reduced installation and maintenance effort and preserved compatibility with existing SCADA operations.

City of Mesa

Dan Darms

City of Mesa