Rex Hospital adopts customized SCADA system to manage emergency power system
Rex Hospital in Raleigh, N.C., is the flagship hospital of UNC Rex Healthcare. The growing facility’s 2,000 physicians and nurses treat tens of thousands of inpatients each year. That number is expected to grow as the hospital has proposed adding a seven-story heart center and possibly a cancer center.
In the midst of this growth, Mike Raynor, retired facilities services director, knew that the hospital would have to invest in its emergency power system to keep up with patient demand. The hospital previously operated an open-transition power system that relied on generators and fuel tanks on flatbed trucks to provide additional capacity during construction or when adequate power could not be delivered to the hospital. Raynor presented a proposal to hospital leadership to invest in a fail-safe, closed-transition system that would allow for transfer between utility and generator sources without a power interruption to the hospital.
The design meant replacing the utility substation and making it more reliable, as well as relocating the switches and switchgear from cramped quarters in the main hospital building to a newly constructed central energy plant. The entire project and system switchover was completed with only a single, planned 10-second outage. The new comprehensive power system provides the hospital with more reliability, more redundancy and more flexibility.
In addition to the new equipment, Raynor knew that investing in specialized software to optimize the system’s management was worth the up-front cost. The hospital worked closely with Russelectric Inc. to design a supervisory control and data acquisition (SCADA) software system.
Russelectric, based in Hingham, Mass., develops systems that can provide sophisticated control functions, including emergency/standby power, peak shaving, load curtailment, utility paralleling, cogeneration and prime power.
The software provides interactive monitoring, real-time and historical trending, distributed networking, alarm management, and comprehensive reports around the clock for every detail of the entire power system, not only the backup components.
According to Raynor, Russelectric was the only supplier that could meet his team’s specifications. “A project like this requires a high level of support service and time to get a reliable, yet flexible system. None of the other competitors was willing to step up.”
With this system, technicians can fully monitor and control the entire power system from the control room at the central agency plant. An operator uses full-color, point-and-click computer-screen displays at the system console to access and change the system’s programmable logic controller (PLC) setpoints, display any of the analog or digital readouts on switchgear front panels, run a system test or view the alarm history. A dynamic one-line diagram display uses color to indicate the status of the system, including the positions of all power switching devices. Operating parameters are displayed and updated in real time; and flashing lights on the switchgear annunciator panel flash on the SCADA screen. The system also includes event logging, alarm locking and help screens.
The system allows the scheduling of tests and automatically generates regular reports required by The Joint Commission. In the event of an internal failure, the SCADA system can rapidly and automatically configure a path to bypass the failure and re-energize the system without starting the generators.
The SCADA system’s full manual backup was another key advantage. If the touch screen fails, operating personnel can manually open and close breakers, synchronize and parallel the generators onto the bus, and add or shed load. Full manual operation was a vital feature in Rex Hospital choosing this system.
The SCADA system includes a simulator that shows trainees what to expect when they lose a feed, open or close a breaker, or add or remove load. The simulator uses the same control logic software as the switchgear’s PLCs. The crew also uses the simulator during startup and for trouble-shooting, system improvements, preview testing and tours.
“The hospital needed a modern system that built on what we had already,” Raynor says. “Working closely with Russelectric, we came up with a very sophisticated system, and we’re at a point now where the system is functioning as we expected — all the hospital’s electrical needs are covered.”