Consulting-Specifying Engineer - February 2009 - (Page 20)

3. Replacing the existing emergency generators and transfer switches 4. Cleaning up existing electrical equipment and correcting code deficiencies 5. Expanding the existing head-end fire alarm system 6. Expanding the existing sub-basement and tunnel system to distribute electrical systems across the campus. The renovation: an opportunity to clean up All too often in many hospital expansion and modernization projects, the natural tendency of electrical design engineers is to avoid older or non-code-compliant electrical infrastructure and equipment. It is often easier to install new equipment to serve the new project area, but sometimes the best solution for the hospital is to clean up existing distribution equipment or systems that are not in compliance with NEC-517. This might involve removing noncomplying loads (recircuiting the soda vending machine from a life-safety panel to normal), refeeding a panel with a prop- erly sized feeder, or replacing 10,000 AIC breakers in a 35,000 AIC panel. Upgrading older or noncompliant equipment also can help save space in the hospital by reducing the area needed for redundant electrical equipment. It also can save money. At Frederick Memorial Hospital, since the six phases of the project touched nearly every piece of the hospital, simply avoiding existing electrical infrastructure was not an option. Replacing all of the existing distribution with brand-new equipment was not possible either, due to obvious budget, phasing, and operational constraints. So a holistic approach was developed: • New head-end equipment to meet capacity, flexibility, and reliability needs • Removal of extremely old and malfunctioning equipment • Cleaning up of existing electrical distribution wherever possible. Cleaning up of equipment consisted of ensuring that electrical loads were on the proper branch of the distribution system. For example, several distribution panels were a mix of critical and equipment loads, or a mix of critical and life-safety loads. In most cases, it was simply a matter of moving one or two loads from one distribution panel to another to achieve strict code compliance. Some panels were simply re-fed to the proper branch. Cleaning up also included seemingly simple things, like providing new typed panel schedules, providing proper breaker labeling, and providing color-coded, engraved nameplates for panels that clearly identified the panel’s name, branch of power, voltage, and where it is fed from. These simple items go a long way to creating and maintaining clean, code-compliant distribution branches. The big addition: an opportunity to modernize The Mayo Clinic in Jacksonville, Fla., expanded its two-story clinic building into a six-story, 500,000-sq-ft, 214-bed hospital by adding three floors of diagnostic and treatment space, a mechanical penthouse, Testing equipment via electrical commissioning Commissioning is one of the new buzz words in the AEC industry. When most people hear the word “commissioning,” they immediately think of mechanical equipment. But commissioning of electrical systems is nothing new to many hospital design engineers. Commissioning of electrical systems should be an integral part of any hospital project but especially of a renovation, expansion, or modernization project where new electrical equipment and system components are connected and intertwined with existing equipment. Proper electrical commissioning will confirm that these systems function properly. Ensuring that electrical infrastructure is functioning properly, the way it is intended to, is essential to the safety of both patients and hospital staff. Typical electrical systems that are commissioned include emergency power systems (generators, paralleling gear, transfer switches, and fuel systems), grounding and equi-potential grounding, fire alarm systems (including air-handler shut-down), and nurse call systems. All phases of the commissioning process, but especially the functional testing phase, should include hospital operations and maintenance personnel, and a formal commissioning report. This assures that the operations staff, who ultimately will be responsible for operating and maintaining these systems, understand how the systems were designed and how they are intended to operate. It also assures staff that everything is properly documented. Engineers commission the emergency power systems at the Mayo Campus Central Utility Plant. Verifying breaker types and settings is a vital part of electrical systems commissioning. Photo: TLC Engineering for Architecture 20 Consulting-Specifying Engineer • FEBRUARY 2009

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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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