Q: How can I annunciate these existing guest room smoke alarms at the front desk when they activate?
This can be done a couple of ways. Keep in mind that this is not a function or feature required by the building or fire codes — it is an ancillary function that the owner wishes to incorporate into their building management model. Since it is not a regulated fire safety function, the supervision of wiring is not mandated.
The latest edition of NFPA 72 identifies these circuits as “Class E,” and the failure of the wiring path between the smoke alarm relay and the front desk will not cause a “trouble signal” if it should fail. Since any failure of this wiring will not cause the failure of a code-required life-safety function, a trouble signal is not required to be indicated. These annunciator systems are merely providing a “nice-to-know” function for the building owner. Existing smoke alarms can accomplish this using a listed relay made for this purpose.
If you are using smoke, CO or heat alarms made by BRK or First Alert, or any of the 21-plus alarms (including smoke, heat and CO) manufactured by Kidde, then a UL-listed relay may be used for remote indication whenever these alarms activate.
Both relay modes require 120 volt AC input to operate, but since they are not required by code, standby power is also not required for these ancillary devices; however, hotels and motels are permitted by the IBC to eliminate the use of standby batteries in their smoke alarms if they connect the smoke alarms to an emergency power source. When the hotel/motel uses this emergency power option, the annunciation of guest room smoke alarms will also continue to operate during power outages.
If the owner will not provide an emergency power circuit for the smoke alarms, then consider using the Gentex 9000/9003 series smoke alarms. These models have built-in relays that will operate during loss of primary power. The Gentex model 9123 uses an auxiliary relay and also provides a temporal-three sounder. Guest rooms or suites that need more than one smoke alarm will, of course, require interconnection so that all the smoke alarms sound within the unit and remotely annunciate whenever any one of them activates. Note that interconnected smoke alarms are not required to have their temporal-three signals synchronized.