Pennoni Perspective Volume 23 • Issue 1 • Spring 2019 - Page 24

GENERATING A SOLUTION Educational Testing Services (ETS) is a non-profit organization that works with education institutions, businesses, and governments to provide assessment programs, research and customized products and services designed to improve teaching and learning, expand opportunities for learners and communities, inform education and policy, and advance the field of educational measurement. Pennoni has provided engineering services to ETS on more than 1,000 projects at their Princeton (Headquarters) and Ewing, NJ locations since 1994. In 2011, the tight positioning of the 5kV distribution equipment in their mechanical building was flagged as a significant hazard to the continuity of the system. The confined space in the building prevented a solution from being provided until it could be moved out of the building to its own structure, a modular building. ETS selected the details of the building and the site contractor was to install all site specific infrastructure. When the building was delivered, the rest of the installation could begin. The campus could have maximum 12 hours shut downs and no power could 24 | P E N N O N I remain in the ground and be a safety hazard to the new work. After creating a final configuration plan, a temporary plan was also created as an intermediate step. To provide the maximum flexibility, two separate transformers, each with their own lines, configured in a main-tie-main with both able to serve all loads and provide additional reliability. The generator, connected to only one of the lines previously, was now connected to both lines and a control system to apportion the available energy was needed. With this control requirement noted, it was also decided to combine the control of this generator with another larger generator at the campus central service location. These two generators, if coordinated properly, could handle the entire campus on all but the hottest of summer days, when loads are reduced by closing buildings and other energy saving measures. The modular building was pre-purchased by ETS and was planned to be 62 feet long and 16 feet wide delivered as a single unit. The site contractor installed the conduit banks