Power solutions for growth of a major medical center.

Many healthcare campuses nowadays are reassessing their utility service and internal power distribution strategies. A number of factors have contributed to this trend. Not only have healthcare campuses expanded greatly over the past half-century, but reliance on ever more sophisticated electronic equipment continues to increase, and electrical rate structures continue to evolve. A $120 million consolidation and expansion at Stony Brook University Hospital, in Stony Brook, N.Y, required just such a reassessment of existing power services and strategies.

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For the $120 million project, consisting of 150,000 s/f of renovated space and 150,000 s/f of new construction, the design team was asked to study the impact of this growth on the existing normal and emergency power services and to implement extensions to the new and renovated area while avoiding service disruptions during construction.

To service a new double-ended substation at the new building, a new ductbank system extended two new 13.8 KV feeders in a loop arrangement to the new facility in separate ductbank/manhole systems to help physical separation and redundancy.

In a new Women and Infants' Center, a new 480-volt switchboard arrangement located on the fourth floor provided for an automatic throwover of the main-tie-main arrangement, ensuring that two breakers are closed at any one time to maintain reliability. Two levels of ground fault were provided at the switchboard to meet code requirements. Clean general building power, life safety, and critical loads were separated from HVAC, elevator, and fire pump loads located on the opposite side of the tiebreaker. A 1,000-amp busway was extended through strategically located vertical normal power electric rooms to service the building floors.

Campus emergency power systems offered another design challenge. The existing power plant housed two generator plants, one at 480 volt and one at 13.8 KV. The 480-volt generating system consists of three 600 KW units individually stepped up to 13.8 KV and extending to 13.8 KV to 480 volt stepdown transformers at the existing hospital. The load side of each transformer was dedicated to 480 volt buses servicing critical, life safety, and equipment loads. These buses were tied together with normally open tiebreakers to allow some redundancy after load shedding. The 13.8 KV generator plant consisted of one 2 MW generator, which was dedicated to the Heart Center. Space was made available for two additional generators and paralleling switchgear. To accommodate the new Women and Infants' Center, a second 2 MW, 13.8 KV generator set will be added in the space available in the plant.

THEODORE G. FOWLER, PRINCIPAL, CANNON DESIGN, & RONALD HILL, ASSOCIATE VICE PRESIDENT, CANNON DESIGN.