Protecting hospital power
The standby power system at Halifax Health helps ensure emergency power safety at the medical center in east central Florida.
-- Consulting-Specifying Engineer, 11/1/2009 1:00:00 AM
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Halifax Health, located in Daytona Beach, Fla., is the largest medical center in East Central Florida. The center has 944 beds and 500 physicians representing 46 specialties. Founded in 1928, the hospital has continuously expanded over the decades and recently added the new, 10-story France Tower to its campus for inpatient and emergency treatment. For the addition, the administration selected a 4.5 MW MTU Onsite Energy standby power system from Florida Detroit Diesel-Allison, the local distributor for MTU Onsite Energy.
“Summer 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.”
Previously installed standby power systems were sized to provide emergency power only for operating rooms, intensive care units, and egress lighting to meet life-safety codes. The older standby generators weren't sized with the capacity to power the HVAC systems. The hospital officials sized the MTU Onsite Energy system to supply all loads in the new tower, including HVAC, in accordance with Florida Building Code.
Chapter 419 of the Florida Building Code states that “All occupied patient care areas and patient support areas shall be supplied with sufficient HVAC as determined by the facility to ensure the health and safety and well-being of all patients and staff during and immediately following as disaster…as determined by the facility, these selected HVAC systems and their associated support equipment such as control air compressor essential to the maintenance of the occupied patient and patient support area(s) shall receive their power from the emergency power supply system.”
The power system in the France Tower consists of three 1,500 kW 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. As required by NEC Article 517, the electrical loads are prioritized and segmented and include up to eight automatic transfer switches per generator set. If an outage occurs, all three generator sets start and assume the load when they are up to speed, which takes roughly 10 sec. 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 fuel. Supplying the three generator sets are two 30,000-gal. fuel tanks. When completely full, they hold enough fuel to operate the standby power system for more than four days at a 75% load.
Throughout the medical campus are various UPS systems to supply power immediately after an outage while the standby generators start. The largest UPS systems supply the medical center's data center and operating theaters. In addition to the standby power system and multiple UPS systems, Halifax Health has dual utility feeds from separate substations in case there is a transmission problem with just one line.
The hospital has made decisions that will help ensure that all the critical loads in the medical center are backed up with reliable standby power, no matter what Florida weather sends their way.
| Acknowledgements | ||
| Informaton provided by MTU Onsite Energy. | ||
Maximizing MCF standby power
10/31/2009MEP Insider
07/19/2009BAS Flies Standby
08/31/2002Whole-building shutdown tests
10/31/2009
