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WSSHE NEWSLINE

WSSHE NEWSLINE

Volume 53  |  Summer 2006

Contents
President’s Message
Transformer Paralleling Technique for Purposes of Equipment Replacement
Legionellae (Also known as Legionnaires’ Disease)

President’s Message:

I hope this finds each and every one of you doing well in both your professional and personal lives.

May God bless you.

WSSHE is alive and doing great. Our Semi-Annual Symposium in Chelan was a great success thanks to your Board’s hard work and the work of the education committee. You will soon see that out ‘keynote’ speaker, Marshall Pierre has received the top humanitarian award from his peers in his professional organization. No surprise there and a huge ‘job well done’ from all of us at WSSHE.

Shortly after the Semi-Annual was completed, your educational committee met (Geoff, Phil, Randy, Steve, Gary, and Mike) and we outlined a fantastic dual-track educational program for the Annual Conference and Technical Exhibition in the Tri-Cities. Remember those dates, October 4, 5 and 6. Register early as we are expecting a full house. More information on the Annual Conference is forth coming.

The Eastern Chapter meeting was held in Walla Walla last week. A very good meeting in which discussion was held regarding state surveys, maintenance issues, and by-laws alignment. I have asked that all Chapters post their meeting minutes on our website, along with financial information. It is my belief that this type of information should be available to all members. The more information we all are aware of, the better we will be as an organization.

I would like your feedback regarding the issue of publishing our roster on our website. Puget and Eastern have approved this process. It was discussed at our last board meeting and the direction agreed upon was to proceed. However, if you do not want your e-mail address published, please let me know. I believe that there is a potential of spam related issues but I also believe that risk is very low. I know I just sent an e-mail to fellow engineers regarding issues at SHMC, and it was very convenient to look up members on my address book and get the word out. It is a very useful tool and I certainly endorse putting this on the web.

Again, I want to thank you all for making the organization a dynamic, healthy, growing entity.

Last issue, ASHE in Boston. Coming up on July 9. WSSHE will be well represented and I look forward to accepting the GOLD award on your behalf.

Have a great summer.
Mike Kelly, President
Washington State Society for Healthcare Engineering
 


Transformer Paralleling Technique for Purposes of Equipment Replacement

After a recent transformer failure at Kadlec Medical Center, and with the addition of some basic metering equipment, it was discovered that the electrical system powering the Information Systems (IS) equipment was operating without a comfortable margin of capacity and worse it was overheating due to third order harmonic resonance. Electrical system upgrades were planned, but this issue required a more immediate resolution. The installation of a K-rated transformer to replace a similar sized one, but not K-rated, was decided upon as one of the “quick-fixes” until further upgrades could be made as part of an ongoing much larger project.

The transformers were fed by an Uninterrupted Power Supply (UPS) to the IS circuitry. Three successive experiments were performed to demonstrate the theory and applicability behind paralleling two similarly rated transformers with different impedances to prevent causing major interruptions to the electrical system and thereby ensuring a minimum IS impact. The technique for paralleling transformers, transferring a reduced load, then performing the swap was proposed as a means to eliminate the down time of the IS network. The methodology for this task evolved over time, through much discussion and with multiple experiments based on theoretical modeling.

The first of three experiments demonstrated the theory on a small load and at a reduced overall scale to see if the voltage differential could be measured to assess whether at full scale it would cause too much of a spike to the system.

The data showed that paralleling two similarly rated transformers with different impedances would cause a slight volt increase due to the reduced resistance and loading of the paralleled circuit. It was decided that the missing components should be included on the next experiment to gain an even more accurate model.

The second experiment was run at full scale, using existing electrical feeds and equipment. Line side breakers were reduced in size to accommodate the load to be used in the experiment. Two attempts to initialize the transformers into parallel were made which resulted in undesirable effects.

With the UPS system in normal mode the first attempt to initialize the transformers into parallel resulted in the UPS system trying to switch onto battery power but it failed to do so due to a faulty contactor, leaving the electrical system in bypass mode. It was determined that the UPS safety system detected a small change within the electrical system and defaulted to battery power.

A second attempt was performed with the UPS system although this time the UPS was placed in bypass mode to avoid the contactor getting stuck again if the system tried to fault to batteries (this was suggested by KMC UPS service vendor). Unfortunately, when the transformers were put into parallel for the second time the entire UPS electrical system failed. All further experiments were cancelled for experiment 2 until cause of the fault could be determined.

The contactor on the UPS failed due to dust in the room where the UPS is kept. This could have occurred during a true emergency and was subsequently listed as a maintenance item.

Even after the failed second experiment, management still felt that the paralleling technique was worth more investigation. Thus a third experiment was performed on a less critical section of the power distribution system. In order to obtain specific data, all loads were removed from the distribution except those imposed up by the experiment. This experiment went well. The variations in phase and voltage that were noticed during experiment #3 prompted the addition of checks throughout the actual paralleling procedure as a precautionary measure. The procedure was tested and refined before the actual paralleling was attempted. Safety was the major concern and if any of the readings had been noted to be too large in deviation from expected, the paralleling technique would have been aborted.

While this practice is not a common one, it was deemed worth the risk due to the unique nature of the IS network configuration and its dependency on a single UPS containing multiple single points of failure. This technique was only an option to Kadlec Medical Center because of the advanced engineering effort put forth by its staff and the experience of the electrical contractor with respect to working on live systems. The transformer swap was crucial in order to maintain a reliable IS network for the hospital. The procedure was a result of much experimentation, careful observation and data collection of the existing system. All of these factors combined together to make it a worthwhile event for all concerned and to lessen the impact on staff and ultimately the patients themselves.

Jason Rose
Kadlec Medical Center
 


Legionellae (Also known as Legionnaires’ Disease)

In July 1976 a strange illness began flooding into the Pennsylvania Department of Health. By August 2nd the department realized that all of the reports involved persons who attended the 58th annual convention of the American Legion’s Pennsylvania Chapter held at the Bellevue-Stratford Hotel in Philadelphia July 21-24. Illness struck 221 persons, 72 of them didn’t attend the convention but were in or near the Bellevue-Stratford Hotel over the same period, 34 people died.

This started one of the largest epidemic investigations in history. After months of searching the illness was traced by investigators, which had been named by the press as “Legionnaires’ disease”. Thought to be an unknown bacterium now called Legionella. Unknown, yes but not new. Legionellae had been causing disease for decades. The first known outbreak in a hospital occurred in 1956 when 81 patients at St. Elizabeth’s Hospital in Washington, D.C. developed pneumonia and 14 people died. The cause at the time could not be determined. 12 years later after Legionella was discovered frozen specimens that had been kept from the outbreak had been retested and the results confirmed that Legionella was the cause.

The Legionella bacteria are found in our environment, a puddle of water in the parking lot may contain the bacteria. In most cases there is no cause for alarm, it is when the bacteria has a chance to amplify that it can become a concern. The Legionella bacterium is primarily found in warm water environments. The ideal growth range for Legionella is 95° F to 115° F.

Areas of concern to health care facilities are, domestic water systems, cooling towers, evaporative condensers, respiratory care equipment, showers, faucets, whirlpool baths, humidifiers and decorative fountains. All of the systems listed have been associated with Legionella. Many health care professionals are under the false impression that Legionnaires’ disease is rare; in fact it’s quite common. One reason is most cases of Legionnaires’ disease go undetected. Of the 2.4 million cases of pneumonia that occur each year in the United States, some 10,000 to 100,000 are actually cases of Legionnaires’ disease. However, only 1,000 to 3,000 cases are reported to the U.S. Center for Disease Control and Prevention annuallyı.

Much effort has been focused on the cooling tower and evaporative condensers for controlling Legionella growth, samples are taken on a regular bases from the bulk water for testing. In many cases the domestic water is over looked and it is ideal for the growth of the Legionella bacteria. It is suggested that water samples be taken from all potential sources of Legionella growth areas.

Specific incidents that have caused Legionellae problems in domestic water systems are, water pressure shock, water pressure failure, major construction, new or renovated buildings, as we all know the hospital industry is in a growth period and these situations should be handled with the utmost care.

If you would like to stay in touch with news on Legionellae and out breaks you can go to the web site www.hcinfo.com this is an excellent source of information.

Respectfully,
John Rivard
CH2O, Inc

1 Matthew R. Freije, Legionellae Control in Health Care Facilities, HC Information Resources, Inc., Fallbrook CA, 1996, p. 5. 2.3.
 


The WSSHE NEWSLINE is published quarterly as a service to WSSHE Members. The purpose of the NEWSLINE is to promote the Society by sharing information of interest to the Members. Please send brief articles or information updates to the WSSHE Editor care of:

Geoffrey W. Glass PE, CHFM
Providence St. Peter Hospital
413 Lilly Road
Olympia, WA 98506-5166
email: geoffrey.glass@providence.org
FAX: 360-493-4043
Phone: 360-493-7722.