Health Care Facility Relies on Standby Power for All Loads, Including HVAC
Named in honor of the Bill France family, owners of Daytona-based NASCAR, the France Tower contains one of the largest operating rooms on the East Coast in addition to a central plant that houses the new standby generators, boilers, and chillers. Having a reliable standby power system is not only required by code, but is necessary as a practical matter, because this area of coastal Florida is hit frequently by hurricanes and thunderstorms that cause disruptions in grid power.
POWER OUTAGES COMMON IN FLORIDA“Summertime thunderstorms regularly wreak havoc with our local utility due to lightning strikes, but these outages tend to be of short duration,” said James Sawyer, electrical supervisor, Halifax Health. “However, there’s always the threat of bigger storms. In 2004, Hurricane Charley was a Category 4 storm that took out the entire grid, forcing us to run on standby power systems in older parts of the medical center campus from midnight until about 6 a.m. the next day.” While the new MTU Onsite Energy standby power system has not yet been required to run during an extended outage, strong hurricanes are always a possibility. As testimony to the constantly looming danger, the new France Tower has been constructed to withstand a Category 5 storm, Sawyer said.
While there have been several standby power systems installed in the medical center as it has grown over the years, those systems are sized to provide only emergency power for operating rooms and intensive care units and for egress lighting to meet life-safety codes. The older standby generators weren’t sized with the capacity to power the HVAC systems. Since current codes require patient evacuation if an area is without air conditioning for longer than 36 hours (a real possibility during a severe hurricane), Halifax Health officials sized the new 4.5 MW MTU Onsite Energy power system to supply all the loads in the new tower, including the HVAC.
THREE PARALLELED GENERATOR SETSThe power system for the France Tower consists of three 1,500 kW MTU Onsite Energy generator sets operating in parallel for a total capacity of 4.5 MW. The generator sets are powered by the EPA Tier 2 MTU 12V4000 engine, which MTU says provides high fuel efficiency and the ability to accept full rated load in one step. The electrical loads are prioritized and segmented by up to eight automatic transfer switches per generator set. When an outage occurs, all three generator sets start and assume the load when they are up to speed, in about 10 seconds. If the control system detects that only two generator sets are needed to supply the loads, one generator will shut down in order to economize on fuel, according to Sawyer.
Expansion at Halifax Health is continuing, and the new central plant has room for an additional two standby generator sets. In the meantime, Sawyer and his team are making sure that all the critical loads in the medical center are backed up with reliable standby power, no matter what the Florida weather sends their way.
Publication date: 01/18/2010