January 26, 2005

Medical Center Chooses Vista^® Gear for Electrical System Upgrade.

A medical center in the Southwest U.S. needed to upgrade their electric system as part of a large infrastructure project. The upgrade would include a new 138 – 13.2-kV substation with 12 feeders, along with a significant amount of self-generation.

To improve service reliability, the 13.2-kV feeders would be relocated underground, in six looped feeds to the buildings. Each loop would include an open point so that, under normal conditions, each feeder would serve half of the loop.

The requisite switchgear for this project would need to be automated, and allow paralleling of the utility sources and self-generation. It would also need to provide real-time reporting of voltages, current, switch positions, and more via a fiber-optic link to the medical center’s SCADA system.

Since paralleling of the sources and/or the self-generation could result in available fault current in excess of 30 kA, metal-clad breaker switchgear seemed to be mandatory for the application. But when it was determined that such gear would increase cost estimates three-fold, the medical center decided to look at other options.

S&C’s Vista® Underground Distribution Switchgear was investigated for the application. Vista gear provides all the functionality of breaker gear . . . but at much lower cost. Just one problem: Vista gear has a 25-kA fault interrupting rating.

After reviewing their operating guidelines, the medical center concluded that a 25-kA fault interrupting rating would be more than sufficient for the application. They subsequently specified 10 units of Vista gear in a variety of models, including Remote Supervisory Pad-Mounted Style Model 532 and Model 523, and split-bus configuration Source-Transfer Pad-Mounted Style 523.

Once the project was successfully completed, another two Vista units were purchased, bringing the total to twelve. Today, the Vista gear provides economical, reliable switching and protection to the medical center electrical loads.

Contact your local S&C Sales Office for additional information.