Consulting-Specifying Engineer - February 2009 - (Page 19)

Investigation and analysis: the roadmap Anyone who designs hospitals knows that new hospitals built on greenfield sites do not come along every day. Additions, expansions, and modernization projects are our bread and butter, the most common hospital design projects we encounter. The goal of these projects is usually to modernize the hospital in one way or another, whether to add a state-of-the-art catheter lab suite, expand the emergency department, add a new patient tower, or perform any of a hundred other possible upgrades, renovations, or expansions that happen every day in hospitals across the country. Many times the electrical systems and electrical infrastructure need some modernization and expansion to support these projects. Any such project usually begins—or at least should begin—with the investigation and analysis phase. This is the phase where a team of engineers and designers investigates, confirms, and documents the hospital’s electrical infrastructure. “As-built” documents rarely are, so we need to verify all aspects of the electrical installation. After verifying the existing infrastructure and analyzing the existing loads (12-month or 30-day recorded demand loads, times 125%, as required by the National Electrical Code (NEC) 220.87, 2005 edition), we begin looking at every level of the electrical distribution system: the existing loads, the new anticipated loads, and the projected loads in five years. Code analysis also is an integral part of this phase, not a separate activity or action. We must always keep an eye out for code deficiencies in the electrical systems. Just because we see a 600-amp breaker serving a 600-amp panel, we cannot assume there are actually 600 amps of wire in between the two. Or just because the existing drawings show two levels of ground fault protection on the main service (NEC 517.17) does not mean it was installed that way. We must verify it. Some code deficiencies are obvious and jump right out at you—no life-safety Modernizing electrical infrastructure might include replacing obsolete automatic transfer switches with new four-pole, dual motor, bypass isolation transfer switches. Four-pole switches are essential to ensure proper ground fault detection. The bypass isolation feature allows for maintenance of the switching mechanism without interrupting power to the loads served by the automatic transfer switches. All photos: TLC Engineering for Architecture branch in the hospital, or a fire alarm system without voice-evacuation capability in a high-rise building, for instance. Other code problems are more subtle, such as insufficient ampere interrupting capacity (AIC) ratings or lack of selective overcurrent device coordination. These require detailed calculations and studies to determine if there is a problem. This is all part of the investigation and analysis phase, which is critical before any hospital electrical systems modernization project can begin. Frederick Memorial Hospital in Frederick, Md., is a large regional hospital with a modern central energy plant and reliable, flexible electrical infrastructure. But in 1998 it was a smaller facility with piecemeal electrical distribution. Like many hospitals, it had a combination of obsolete electrical equipment, aging equipment, and relatively new distribution equipment. In 1998, Frederick Memorial Hospital began a multiyear, multiphased project (originally called Project 2000) that was completed in 2006. The project began with a detailed investigation, analysis, and recommendations report. A team of engineers and designers spent more than three months to complete the report, which ultimately filled a 4-in.thick, three-ring binder. The report analyzed every electrical system in the hospital, from normal and emergency electrical distribution, to nurse call and fire alarm, to voice-data and security systems. The report’s recommendations were accepted by the hospital and became the electrical systems roadmap for each of the phases. The recommendations for modernizing the hospital’s electrical systems and supporting the six phases of the project included: 1. Expanding the central energy plant 2. Upgrading the electrical service Consulting-Specifying Engineer • FEBRUARY 2009 19

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Consulting-Specifying Engineer - February 2009 Contents Viewpoint News M/E Roundtable Codes & Standards Electrical Modernization: A Tale of Two Hospitals Retrofitting Office Lighting Controls Case Study New Products Equipment Lifecycles Advertiser Index Green Space

Consulting-Specifying Engineer - February 2009

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