Fire Alarm information for dummies


Basic Fire Alarm information

Manual Pull Box or Pull Station: This is the Red square box with the handle you pull when there is a fire. The fire alarm box.

Horn/Strobe: This is the flashing light that also has an obnoxious sounder on it. Many times it will sound in threes beep, beep, beep then repeat. These can be white or red depending on the building. New requirements are coming out where some of these may have a clear flasher for fire and a colored flasher for other type warnings for disasters or something else. There are also Speaker Strobes that look similar that have a speaker with a voice message telling you to leave, stay put or giving other information. These were known as VOICE EVACUATION SYSTEMS but now many are going to what is called MASS NOTIFICATION because sometimes these systems don't evacuate people but tell them to move to another area of the building or stay put.

Duct Detector: This is a smoke detector mounted to the ventilation system so you know when there is smoke in the air distribution system. It can also shut off equipment if the motors are burning up. When there is smoke it can send a supervisory or an alarm, it can shut down all the air handler units or just one. Shutting them all off is called global shut down.

FLOW SWITCH: This is an electrical low voltage monitoring switch that tells the fire alarm panel that water is flowing. This switch activates and alarm and normally the fire department is dispatched.

TAMPER SWITCH: This is an electrical low voltage monitoring switch that tells the fire alarm panel that someone has shut off the water to the fire sprinkler system. This could also indicate a problem with wiring or sometimes when construction or service is being done these signals are activated to indicate a problem.

PIV: Post Indicator Valve, this is normally found outside a building and monitors whether or not the water is turned on or off for the fire sprinkler system going into a building.

HEAT DETECTOR: This does not need much explanation other than to say this is not a life safety device but these are meant more for protection of property and the structure of the building. There are fixed temperature sensors that go off and activate the fire alarm at normally 135 degrees F or 194 or 200 and there are Rate of Rise heat detectors that (ROR) that are activated if the temperature goes up very quickly within a certain amount of time and within so many degrees. There are also one time use heat detectors and others that that be reused over and over. You cannot test a one time use heat detector. It has a eutectic metal that melts at a specific temperature. The other heats can be tested with a heat gun. Sometimes the fire marshal will let you use a heat detector where you would normally find a smoke detector if circumstances require it. Example: If you normally have a smoke outside of an elevator which is code you could put a heat there instead if the elevator opened up to the outside where a smoke could get cold or dirty.

SMOKE DETECTOR: Everyone knows what a smoke detector does although many people don't understand there are different kinds of smoke detectors. Two types are the ION and the PHOTOELECTRIC type smokes. ION is not the best choice here in Utah because they false alarm more in higher altitude areas. ION detects invisible smoke better like burning wires and such. ION detectors have a small portion of radioactive material inside so you can't just throw them away in the garbage. Photoelectric sends a beam of light out though a maze inside the chamber and when smoke breaks that beam of light the alarm is activated the problem is that dust and steam can also affect these detectors. There are new detectors out that also have a CO sensor in them to avoid alarms in steam or dust environments. Some of these are not UL listed as CO sensors so you may need a separate CO sensor as well.

Annunciator: Also known as a Keypad where you can see your alarms and troubles.

CODE WORD OR PASSWORD: Code requires that you have a password for your alarm system so not just anyone can call in an put it in test and then arson the building and not have the fire department show up. When people are let go or fired this password should be changed.

Monitor module or POPIT: This is a small little device that will send a signal to the alarm panel telling it where the device is. If you have a smoke detector in the SW back of the building and you have one of these modules on the system it will give the panel the exact location after it is programed to do so.

LOOP or WIRE RUN or CABLE LOOP or WIRE CIRCUIT: When we install fire alarms or security alarms we can install them in a zoned (conventional) manner or an addressable manner this means that wire goes out to each device in a loop and if you have addressable modules tells the panel where each device is. If you have a zoned system then there is a wire that goes from the panel to each device using much more wire and if you have 15 devices then there are 15 wire runs and that is not in a loop. One circuit may have 15 smokes on it and still be conventional or zoned but you will not know where each device is or which one has gone into alarm without going out and looking at each one so the addressable configuration has an upside to it. Class A wiring means the wire goes out to all the devices and then comes back to the panel in a separate conduit or path. Class B means wire can go out and then stop at the last device. If the wire is cut on a class A loop then all the devices will continue to function and the panel will show a trouble. If a wire is cut on a class B loop, you will get a trouble and none of the devices after the cut will function.

NFPA 72 or NFPA 70 (NEC) and IFC: NFPA means National Fire Protection Association and the 72 is the Fire Alarm Code and the 70 is the Electrical Code or National Electrical Code NEC and IFC is International Fire Code. These codes have been adopted by Utah with some exceptions in R710 which is the Utah Code although Fire Marshals can require additional items or give you exceptions and all of these should be in writing.

ANSUL TIE IN: Alarm systems normally just monitor the ANSUL or the systems that dump chemical or liquid out to put out a fire in a kitchen.

GREEN TAG: The sprinkler system and the fire alarm system should be inspected and tagged separately. There is a different certification for each one of these. If one company does both they need to indicate the proper inspection and the numbers on the Green Tags. When the sprinkler system is tested they also test the functionality of the fire alarm where the sprinkler system is concerned and when the fire alarm system is tested they also test the flows, tampers and PIVs on a system although most fire alarm companies will not flow water but that is normally done by a sprinkler company. Most fire sprinkler companies do not test all of the fire alarm components as a fire alarm company does.

NFPA 72 INSPECTION FORMS: You should ask for these forms when your system is installed and inspected yearly as per code.

Elevator Recall: The fire alarm system has a smoke outside the elevators and if smoke is detected say on the first floor then the fire alarm system tells the elevator system to send the elevators to a different floor where there is no smoke. It is a bit more complicated that this but this is basically how it works. If there is a fire on say the 5th floor then the elevator will be sent to the 1st or ground floor so people can exit.

Shunt Trip to shut down power in the elevator shaft: If there is someone working in the shaft and say a detector indicates a fire or extreme heat then the fire alarm system tells the electrical system to shut off the power to protect the people working in the shaft from being electrocuted.

DAMPERS: There are vents in the ventilation system and some of them can be opened or closed and these can be tied to the system so they automatically shut or open. This could be done so smoke would not spread throughout the building.

SMOKE CONTROL SYSTEMS: In large buildings this is similar to dampers but more complex because the fire department could respond and enter a safe room normally on the perimeter of the building that had controls where they could open and close vents and dampers and turn on and off fans so they could move smoke from one area of the building to another area.

When you find errors in this information or something you feel needs to be clarified more please comment so corrections can be made. I have tried to make this information easier to read for those that are not involved in the industry and by so doing it may appear that some of the information is not complete.

DOOR HOLDERS: These are magnets that hold the doors open and they drop power when there is a fire so the fire does not spread.

SECURITY MAGLOCKS : These are also tied to the fire alarm, these magnets do the opposite, they are holding a door shut but when there is a fire alarm power should drop to these as well so people can exit the building.

24 HOUR BATTERY TEST: This is a test that is done to make sure your batteries are big enough and good enough to run your fire alarm system after power has been out for 24 hours. The system will run on battery and then the fire marshal will have the contractor set off the alarm for 5 or 15 minutes and all the horn/strobes or speaker strobes need to function for a specific time period. If they don't then you may need new or larger batteries or even a new power supply. Most circuits can only have about 8 horn/strobes tied to them so if a contractor puts too many on one circuit then the last ones may not work if there is a voltage line drop. This means there may not be enough power at the end of the wire if the first horn/strobes took all the power. Some of the newer systems can have more than 8 on a circuit so that is why the fire marshal likes to see the battery calculations and the voltage line drop calculations. It is like putting 150 watt bulbs into a lamp that is rated for 60 watt bulbs. The wire size matters and the distance matters and the appliances you put on the wire also factor into these calculations.

I hope this has been of some help to those that are new in the industry or for an owner that would like to get more involved with his building. Call Larry Love at Peak Alarm for more information 801 428 1384 or email him at I welcome corrections and comments.