GMI breakers go to college

Author: Jason Cossette


Siemens’ reliability and expertise of type GM switchgear proves trustworthy during expansion at North Carolina State University.


Situated in the capital city of Raleigh, North Carolina, more than 30,000 students roam the campus of North Carolina State University (NCSU) annually. Summers can be described as sweltering, with temperatures often climbing above the century mark and humidity levels as equally uncomfortable. Average temperatures in the area range from nearly 80° to 90°F May through September, creating the need for reliable relief from the outside elements.


In 2011, NCSU began expanding their air conditioning system and called on Siemens to install and test new switchgear which would increase load capacity for the system. With Siemens switchgear successfully utilized across campus, the university found it easy to choose Siemens products for their additional needs for various reasons.


Performance matters


NCSU chose the Siemens 5kV type GMI breakers, which are designed for use in industrial plants, commercial buildings, electric utility systems, cogeneration installations, and other electrical systems. They are commonly used for protection and switching of transformers, motors, generators, capacitors, buses, distribution feeder lines, and in general, for protection of any medium-voltage power circuit. Furthermore, the switchgear structure and the drawout vacuum circuit breaker are an integrated design with dielectric, thermal, and interruption integrity built directly into the basic design. Taking these attributes into consideration, facility managers spend less time focused on maintenance or worrying about outages. The equipment also meets or exceeds the latest standards of ANSI, IEEE, and NEMA, ensuring reliability for the future.


Easy and safe to install, operate, and maintain


When dealing with facility constraints, maintenance technicians are keenly aware of the space-saving design of the Siemens type GMI breakers. The type GMI 5kV metal-clad power switchgear assemblies utilized at NCSU boast a horizontal drawout while taking advantage of the latest developments in vacuum interrupter technology. Up to two circuit breakers can be stacked in a single vertical section and auxiliary cells can be easily interchanged, enhancing the versatility of the design. This was the perfect solution for the Cates Avenue Steam Plant on campus.


Because NCSU already had similar switchgear, the installation of one vertical section of switchgear and two circuit breakers was simple and cost effective. As described previously, the equipment was quickly added with ease and without the intense training of personnel required with other solutions. Due to Siemens’ extensive knowledge of the system in place and the requirements to upgrade, the project managers involved were able to coordinate a detailed schedule with minimal outages and finish the project ahead of schedule.

Mailing address

Siemens Industry, Inc.

7000 Siemens Road

Wendell, North Carolina 27591

United States