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MRI Rooms and Preaction Systems

Question asked by bob.northelectricllc on Dec 7, 2015

MRI Rooms are new, and the use of Preaction Sprinkler Systems in MRI Rooms are perhaps newer.  Two years ago while preparing and researching how I was to go about meeting the needs of my customer who had to have the preaction dry sprinkler system in use with their MRI facilities, I discovered that virtually no one knew anything about either, especially about what a preaction system is.  I successfully got through with the installation of a conventional smoke detector system for the conventional releasing panel, being supervised by the primary addressable FACP, including the ability to address which room the smoke emergency occurred in.  It is essential to locate which room has the smoke event.  "Is it in the basement IT Room, or on the second floor in one of the MRI Rooms, or the closet?"


Four wire System Sensor smoke detectors, with relay bases, monitored by MMR-301 modules.  It's a lot of work.  Four wires to operate the detectors, and an additional two wires for the module.  Then, there are 10 soldered connections to make at the MRI Wiring Filters.  The MMR-301 modules must stay out of the MRI Rooms, because they cause a trouble condition at some point in the MRI operation.  The systems function well so far, but I still have questions regarding the UL Listings and the functioning of the devices we have available on the market today.  There are too many questions in my mind and too little time to do the work.


If the MMR-301 is interrupted by the MRI, then would an SD355 likewise be affected?


I'm told, after the fact and in contradiction to a different techie, that the 4 wire System Sensor smoke detector is not UL Listed for MRI, nor did he think the coupling of the relay base to an MMR-301 proper.  So then, how are we to address and monitor multiple areas by the use of the conventional releasing panel?


Even if the releasing panel was addressable, how do we pinpoint the location of the smoke directly to central station, without the use of two account numbers, and 4 communications lines?  Even then, is the SD355 going to work?


Is the industry prepared to meet the challenges above, or do we need more devices to be UL Listed for these purposes?


Bob Sanders