Edwards Fire Alarm FAQs v2

5 2 2014 Alarm FAQs The size of a fire alarm panel is determined by a number of factors including size of the building the number of devices and the job requirements A zone a defined area in a building in which related functional items work together This include things like alarm annunciation the panel will indicate what area of the the alarm occurred and alarm notification signals will only activate in areas of the building not general alarm On a conventional fire alarm the terms zone and circuit are often interchanged one circuit could cover zone On an addressable panel the zones are created in software you can devices to zones Circuits on a fire alarm panel also have limits as to how devices you can connect to them The more devices the larger the panel also up to the engineer designing the system as to how he wants to divide up building A single zone conventional panel for example may be able to enough devices to cover a given building but you would be limited in terms annunciation at the panel because you won be able to tell where in the building alarm came from The brightness requirements candela of a strobe is determined by where it is installed The larger the room the brighter the strobe NFPA 72 National Alarm Code sets the standards for this and provides a chart with different room along with the strobe requirements for each If an area needs multiple those strobes must also be synchronized with each other flash at the time See also How can I synchronize the strobes on the fire alarm ANSI A17.1 is the national elevator code but local codes may be different You always refer to the proper codes for your area for exact requirements you will need the following a smoke detector located in each elevator a smoke and or heat detector in the elevator machine room the heat if there sprinklers a heat detector located at the top of the elevator shaft if there is a at the top a smoke detector located at the top of shaft if there is a anywhere in the hoist way a set of relays located in the elevator machine to control the elevators primary alternate shunt a visual warning hat indicating if elevators are unsafe to use and a control panel the can be the building fire alarm panel or a dedicated panel if there is no FA How many zone circuit fire panel do I need What candela strobes do I What do I need for elevator The number of devices you can connect to a signal circuit NAC is based on current rating of the circuit and the current rating of the devices connected to circuit You must add up the current draw of all the devices and make sure the does not exceed the rating of the circuit you want to connect them to it also good idea not to exceed 80 of the circuit rating to give some margin for error room for expansion To find the current draw for a particular device you refer to the device installation sheet or the device U L product label A alarm device will have a FWR Full Wave Rectified and DC current draw Be sure to use the correct current based on the type of power supply Also aware that multi candela strobe devices will have a different current rating for different candela settings the higher the candela the more current Use the rating for the candela you are setting the strobe to some jurisdictions require you to use the worst case value regardless of how bright the is set check with your local AHJ You must do a voltage drop calculation for each circuit The method for doing should be included with the manual that comes with the fire alarm panel or power supply You will need to know the following information to do the 1 The minimum operating voltage of the signaling device for a UL 24 volt device this would be 16 volts 2 The maximum operating of each device and therefore the total current draw of all devices to the circuit 3 The minimum circuit voltage rating of the NAC 85 of nominal 24v or 20.4 volts but refer to panel manual for correct 4 The resistance of the wire used for the signal circuit Panel installation manuals should include this information it is not the same for panels Typically it is based on the circuit maximum allowable resistance The distance you can run the wire on an addressable loop is determined by the and type of wire used and the number of devices You should refer to the fire panel manual for this information NFPA 72 National Fire Alarm Code sets the standards for what required For mode signals must produce a sound level of at least 15dB above the ambient sound level or 5dB above the maximum sound level having a of at least 60 seconds whichever is greater measured at 5 feet above the throughout the covered area Fire alarm systems must have a secondary means of power in case of AC failure Battery calculations will determine what size batteries are needed should be included with the panel or booster power supply manual You will to know the following information to do the calculation 1 The required time typically 24 hours 2 The required alarm time typically 5 minutes The panel total supervisory current draw 4 The panel total alarm current including signal load How many signals can I to the fire alarm panel Notification Appliance How far can I run the signal NAC wire on my fire alarm How far can I run the IDC Device Circuit wire on fire alarm panel How far can I run my loop wire How loud do my signals need be What size batteries does the alarm panel need What type of device should I in a kitchen a smoke or heat detector It is generally recommended that fixed temperature heat detectors be installed kitchens Every day cooking activities can cause smoke detectors to alarm and of rise type heat detectors can be set off by the sudden temperature increase to an oven door opening If the ambient temperature in the kitchen does not 100 degrees F then you can use a 135F detector Otherwise you would to use one with a higher temperature rating like 194F In general class B wiring is a pair of wires from a fire alarm panel circuit that plus and minus in and out of each device in parallel with an end of line wired across the plus and minus of the last device note an addressable SLC would not have an EOL resistor Class A circuits wires to the devices the same way except that instead of an end of line resistor after the last device wires are returned back to another set of terminals at the fire alarm panel With B wiring if there is a break in the circuit every device after the break will stop With class A wiring power communications to the devices is fed from 2 so if there is a single break in the wire all the devices will continue to You should always follow the manufacturer instructions provided with the In general a functional test of a smoke detector can be done by using a of aerosol smoke recommended by the manufacturer For Edwards Signaling the can is sold under part number P 047546 0025 Some detectors have mechanical means of testing ie magnet test such as the Edwards 500 and 700 devices but this does not substitute for a functional test using smoke In to a functional test a calibration test must be done to check the sensitivity the detector Depending on the device this may require an external meter or measuring device For the Edwards Signaling 500 and 700 series smokes can use a magnet which will give you feed back via the detector LED of flashes For the addressable E series sensitivity can be checked the fire alarm panel NFPA 72 National Fire Alarm Code sets the standard for often smoke detectors are tested You should always follow the manufacturer instructions provided with the In general if it is rate of rise type heat detector you can use a hair dryer or gun to warm the body of the device If it is a combination rate of rise with a restoring fixed temperature element you can test the rate of rise portion you must protect the fixed temperature element from the heat by covering it with If it is a non self restoring fixed temperature only heat detector you test it NFPA 72 National Fire Alarm Code sets the standard for how often must be tested Non restoring fixed temperature heat detectors must be after 15 years or have 2 detectors per 100 be laboratory tested Each NAC Notification Appliance Circuit in a fire alarm panel or booster power has a maximum current rating This information can be found in the provided with the panels The total current draw for all the devices to the circuit cannot exceed the NAC rating Be aware that the NAC rating is diffe