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DISASTER PLANNING & PROOFING to dampen vibration or the inconvenience of a generator located on a higher level of a hospital, with the potential for loss of life during a disaster, this precious real estate is a bargain. Unfortunately, in some instances, hospital disaster preparedness and maintaining well-functioning backup systems are costly distractions from the day-to-day business of hospital operations. That is, until needed. The Joint Commission requires all hospitals perform load tests of backup systems once a month for at least 30 minutes and once every three years for four hours. However, testing will not make a submerged emergency generator start. What is remarkable is that seven years after Hurricane Katrina hit the Louisiana Coast on Aug. 29, 2005, major hospitals still have backup systems in basements where they are prone to flooding. three 500kW generators paralleled together, essentially produces up to 1500kW of power. This is more than enough to handle the facility's load requirements. The problem occurs when one of those 500kW generators fails and 1300kW of essential building load is thrown onto only two 500kW generators. This causes overload and the remaining generators will shut down. The only way to save a system in this instance is to design in a load shedding scheme that will trip off less essential loads, allowing the overall load to drop to a level the two generators can handle. When paralleling generators, a load shed scheme is a must. Poor maintenance There are numerous factors that can play into poorly maintained emergency systems. While generators are tested on a regular basis, it is often found that they are tested at the wee hours of the morning when very few hospital Fuel contamination operations are taking place. With very little load to test Just as vulnerable as a generator in a basement is an underagainst, the generators run fine and pass the required test. ground fuel tank. While tanks are designed to be placed However, this creates a false since of security. And when underground and are sealed from water infiltration, they still those generators are needed in an emergency, the generahave vent stacks. And if the highest level of the vent stack tors fail. is 1-inch below the highest flood water, then contaminated Most likely the generators failed due to "wet stacking." water will fill the fuel tanks through the vent stack. This condition in diesel generators is a result of carbon Another potential problem in high-water conditions is from unburned fuel collecting in the exhaust stack and can buoyancy. During flooding conditions when the soil surback up into the piston rings. If unaddressed, wet stackrounding the underground fuel tank becomes saturated, ing could cause fouled fuel injectors, a decrease in engine the tank can become subjected to buoyant forces that performance, corrosion, premature engine breakdown, could offset the resistance of backfill and hold-down straps significantly shortened engine life and increased maintecausing the tank to shift from its location, potentially rupnance costs due to excessive engine damage. When a turing the tank. If unanchored, the fuel tank could lift out system is needed in an emergency condition, it is unlikely of the ground and float. In either case, the results will be it will operate to its full potential or it could fail. ruptures or the separation of fuel lines and piping, resulting Proper maintenance and testing is essential to maintain in the release of fuel oil into the environment and starving a healthy generator. In the case of wet stacking, the most the generator of its fuel supply. effective way to ensure this doesn't happen is to run generators at least 65 percent loaded during testing. This will Generator overloading allow the engine to run at a higher temperature and burn While most emergency systems are designed to provide out the excess carbon and thus prevent potential disaster. power to cover all of the life safety and critical-branch This means testing under a significant load monthly. If power requirements of a healthcare facility, as well as operationally this is not possible, then the use of a load some of the essential mechanical loads, how could the bank to test the generator against is required. system become overloaded? The bottom line is that healthcare faciliThe real problem comes down ties exist for the health and welfare of the to multiple generators paralleled communities. If it were not for the heroic together, with combined power efforts of so many hospital staff the day It is often found that they generation meeting the needs of the Superstorm Sandy hit the East Coast, the are tested at the wee hours essential emergency power loads situation could have been even more devwithin the facility. This works well astating. However, to assume that nothing of the morning when very until a loss of one or more generalike that will ever happen, or to count on few hospital operations tors during an emergency condition. staff to rise to the occasion is not a plan at are taking place. With very If a facility has not designed a load all, it is a recipe for disaster. shedding scheme into a system, little load to test against, David Rosenberger is a senior project then the potential for failure is real. the generators run fine. manager for Sparling Inc. He can be reached at For example, a facility that has drosenberger@sparling.com. 1300kW of emergency load and has www.mcdmag.com January/February 2013 | Medical Construction & Design 41