Fire Alarm Articles -- Maintenance

How do I Connect a Tamper Switch? -- When connecting sprinkler tamper switches or sprinkler waterflow switches, I have found that the best way to make sure the system is going to work correctly is to not use the labels on the switch inside the tamer switch assembly. Half of the time those labels are wrong. Those labels are for any system, sort of, and not just for fire alarm systems. Instead, use the Ohmmeter to figure out which screw terminals to use...Read More

What Voltage Should Be at the EOL of a NAC? -- The goal, when measuring the voltage on the Notification Appliance Circuit -NAC-, is to make sure that there is enough voltage to turn on all the horns and strobes when there is a fire. The power may be off to the building during a power blackout, but the voltage still has to be there for the horns and strobes to warn people of fire...Read More

What is Causing a Network Fault? -- A Network Fault is a problem (Trouble) with the fire alarm system. The fault has to be fixed before it can be cleared from the panel. To clear the trouble from the display, there's also a trouble memory that requires the troubles to be acknowledged and cleared after fixing the trouble...Read More

How is the Sensitivity of a Smoke Detector Determined? -- To determine how much smoke it takes to set a smoke detector into alarm, sensitivity testing uses a calibrated, portable cloud chamber. It uses a photo-reader, kind of like the smoke sensing chamber inside a photo smoke detector, to sense the amount of smoke in the cloud chamber. The cloud chamber, or testing tool, completely encloses the smoke detector and starts out with clean air. For the measurement, artificial calibrated smoke is slowly introduced into the chamber...Read More

How do I Fix an Open Fault? -- The fire alarm system is supposed to consist of the wiring in the building, all of the input devices -smoke detectors, pull stations, waterflow switches, etc.- and all of the output devices -fire horns and strobes, etc.- Between all of the input zones and output zones is a control panel. There should be an end-of-line resistor at the end of each loop -the pair of wires connected to a zone and connected to all of the devices on the zone-...Read More

What does Open Zone Alert Mean? -- An Open Zone Alert on a fire alarm panel shows that the wire is not continuous. The fire alarm system, being a life safety system, is always checking the wires to make sure the devices like smoke detectors or pull stations are connected at all times...Read More

Is This an Addressable 4 Wire Speaker/Strobe? -- A speaker and a strobe are always separate devices. Many times, as with the speaker/strobe that you show, the speaker and the strobe my be in the same box, but they are still separate devices, they aren't connected together inside. In this case, this is not an addressable device. On the back of the speaker / strobe, there are 4 terminals: 2 of the terminals are for the speaker and two of the terminals are for the strobe. In other words, the terminals aren't for a single 4 wire addressable circuit, but the terminals are for two completely separate 2 wire circuits: 2 of the wires are for powering the strobe and 2 of the wires are for powering the speaker...Read More

How do you Troubleshoot an Addressable System? -- No matter what the panel says, or what a multimeter says, all faults are either an open or a short. Both causes could be in the building wide fire alarm system at once, and there may be more than one problem to contend with. Shorts could be inside a device, in the building wiring, or in the panel- opens could be inside a device, in the building wiring, or in the panel. A ground fault is a short, and ground faults require two shorts in order for a ground fault to affect the fire alarm system. At all times when troubleshooting, keep an open mind. Never assume that you know what the problem is until the problem is fixed...Read More

How do Pathways Affect Ground Faults? -- Ground Faults are a big issue. Almost anytime there is a ground fault on a fire alarm system, the panel displays a trouble. Then, no matter what caused the trouble, the trouble has to be fixed. However, the NFPA has an exception to the rules regarding the displaying of ground fault troubles. For all types of pathways for signal or power in building wide fire alarm systems, the rule of thumb for displaying a ground fault trouble goes something like this, -Whenever there is a ground fault, the panel will display a trouble.- There is an exception to this rule ...Read More

Why Doesn't a Smoke Detector Always Detect? -- The NFPA wants smoke detectors tested in place to make sure smoke enters the smoke chamber. Keep in mind that a smoke detector can't detect smoke that ... Read More

Horns and Strobes for Handicap Apartments -- Multifamily dwellings like apartments, condominiums, hotel rooms, etc., actually have two fire alarm systems: each individual residence's fire alarm system and the building's common fire alarm system. A fire alarm system, any fire alarm system, detects ... Read More

Why Do We Inspect Fire Alarm Systems? -- A long time ago, before regular testing of fire alarm systems was required, the NFPA and other fire protection professionals discovered that large numbers of fire alarm systems just weren't working... at all. Originally, when they were installed, these systems worked properly ... Read More

What Happens When a Fire Alarm System is Tested? -- Once in a while, I can completely inspect a fire alarm system - The system is local only, there is no monitoring company to disable - There are no people around to get confused or greatly annoyed as I sound the alarms... Read More

Should Canned Smoke be Used to Test Smoke Detectors? -- There have been many discussions about the best way to test smoke detectors --- canned smoke or... Read More

Troubleshooting Addressable Ins and Outs -- A fire alarm system's main purpose is to detect fire and then tell people about the fire. A conventional fire alarm system does this detection-telling, and so does an addressable fire alarm system. Besides a better display on the addressable fire alarm system and the extension of the ... Read More

Can a Magnet Really be Used to Test a Smoke Detector? -- Smoke detectors usually have two ways of being tested. Smoke (smoke particles in the air, or some sort of canned smoke), and magnets (the activation of an internal magnetic... Read More

Quadruple Use of the Initiating Device Circuit (IDC)-- In a fire alarm system, the Initiating Device Circuit (IDC) is an input circuit or detection circuit: it carries the alarms detected by devices like flow switches, pull stations, heat detectors, tamper switches, etc. A second use of the Initiating Device Circuit is to monitor itself, it supervises its own wires... Read More

Can We Use Waterflow Switches for Liquid Suppression Systems? -- Can we use the Flow Switches and Pressure Switches that are used with water lines, for fire suppression system, if fire suppression system uses NOVEC 1230 liquid? Read More

Where Should An End-Of-Line Resistor go In A Security System? -- Shouldn't the EOL resistor be physically, actually, for-real be located at the END of the loop, at the farthest point? Otherwise, isn't having the EOL resistor right there at the panel just ... Read More

How Can We Fix Intermittent Beeping Troubles? -- We have a fire alarm system installed ~ 2000, it started beeping trouble, runs through all the points as troubles, then restores to normal. Fire alarm technicians cannot figure it out. Read More

Do I Have to Put The Fire Alarm System On Test? -- It's the owner's fire alarm panel. The owner has bought and paid for the fire alarm system. You may be called... Read More

Is There Any Reference to Font Size for Labels? -- Is there any clear info on the marking as to Font size? As for 10.6.5.2.3 is there a better description for a red marking, one that is uniform with code?Read More

Can the Booster Power Supply be Installed in the Ceiling? -- The fire alarm system isn't going to be removed after the warranty period; the fire alarm system is going to be in place as long as the building stands. Not only that... Read More

How do I troubleshoot a ground fault? -- Troubleshooting a ground fault is like troubleshooting anything else. The first thing to do is stop and think. Ask yourself, what are you looking at? Read More

Can a Real Fire Break Out While the Fire Alarm System is Being Tested? -- That's what the fire alarm system is there for in the first place, isn't it? To shout fire? Keep that in mind when disabling... Read More

Can the Alarm Relay Contacts Be Used For Elevevator Capture? -- Usually those contacts activate with any alarm. To keep the elevator from being captured when a smoke detector in any part of the building goes... Read More

Talk to Management Before and After Servicing-- When a technician is doing something, anything, with the fire alarm system -- people are concerned; they don't like being surprised by seeing someone messing around with their life-safety fire alarm... Read More

Can More Than One Class A Circuit be in a Conduit? -- How many Class A Circuits are in a single conduit isn't really the issue. The issue is separating the feed part of any Class A Circuit from... Read More

Can I Relocate a Strobe Without Reprogramming? -- Do the technicians have to reprogram the fire alarm system after relocating devices just a few inches from their original position?Read More

Do I Have to Go Off Line? -- Do I have to go offline to replace the batteries in the duct detector panel? Also, will I have to reset any equipment or systems? Read More

Can a Button be Installed to Release a Door Holder? -- The workers have to pop the door off the magnet when church starts. Some of the workers are older and have difficulty closing the door. Read More

I'm Having Trouble With a Door Release -- While trying to trouble shoot why the door release for the front door is not working, one of the conductors grounded out against the fire alarm panel chases. This caused the door release to activate. Any thoughts? Read More

Can a Person Just Add a Horn or Strobe to an Existing Notification Appliance Circuit (NAC)? -- In a building that has been remodeled and remodeled, when a fire drill is sounded, have you ever found that a few strobes are running slow or won't even work? Then, when troubleshooting... Read More

What Causes an Open NAC? -- I am going to a job site where on the service call ticket states that a NAC is reading open circuit. What can cause an open circuit on the NAC line? Read More

How many T-Taps are Allowed on an SLC? -- The answer to the question of how many T-Taps is allowed --- is It Depends. It depends on the manufacturer and it depends on how easy the installer wants to make the system for the technician... Read More

Where Can We Get Parts for our Unsupported System? -- Our fire alarm systems are no longer supported by the manufacturers, can you suggest how we can get the parts we may need in the future?... Read More

What is an As-Built Plan? -- The owner of the building project is the beginning of the planning process and the end of the planning process. Conception Plans - How the building ... Read More

Area of Refuge, what should the upkeep and temporary usage be? -- What should be maintenance aspect of Refuge area in terms of Upkeep, Temporary Usage etc.? We often get request for temporary stowing and using Refuge area for minor works including welding. Read More

What Makes Interfacing the Fire Alarm to Elevator Capture Difficult? -- People are afraid of fire. They also know that where there's smoke, sometimes there's fire. That's why they don't want the elevator to... Read More

Standby Batteries - Is there a reason why I shouldn't change them myself? -- I am OK with the cost per battery but I am having a little heartburn over paying someone $115 to do a simple replacement of the batteries. UNLESS I am missing a step that I am unaware of? I believe I need to notify our alarm company that I am changing batteries and to put us in test mode. Read More

It's the Volunteer Firefighter that Reads the Panel -- I suppose it was used because the technician programming the fire alarm system was totally familiar with the acronym AFA and what it means... Read More

Can an SLC loop (Signaling Line Circuit), whether Class B or A, also carry the power to activate (turn on) a horn strobe? -- The Signaling Line Circuit (SLC) is meant to carry signals between addressable devices (Modules and Detectors) and the panel. In some ways, the addressable devices can be thought of as extensions of the panel itself. The SLC can be thought of... Read More

Why Use Pigtails or a UL Approved End-of-Line Resistor? -- Many times, a fire alarm system installer will put the leads of an end-of-line resistor... Read More

If It Aint't on Paper - Did It Happen?-- Paperwork - when things go right, no one reads it - when things go wrong, is that when they read it? Read More

What is the Difference Between an End of Line Resistor and a Terminating Resistor? -- In electronics, at the end of the communication line, there's often a Terminating Resistor. In fire alarm and security systems ... Read More

Can the Ground Fault Light be Used for Troubleshooting?-- A ground fault is an electrical leakage from the fire alarm system to building ground -- somewhere in the building. The ground fault light on... Read More

Does the NO Mean Normally Open of Normally Closed on a Tamper Switch? -- To figure out the normally open and normally closed contacts for switches on fire suppression systems, use ... Read More

Who Really has Job Security?-- If you guard secrets to keep job security, you'll lose it. If you give away secrets to give away job security, you... Read More

When a New Air Diffuser is Installed, Why is the Fire Alarm Company at Fault? -- I was at a lunch meeting where the State Fire Marshal (AHJ) was speaking. One of the things that he talked about... Read More

When Talking to Customers, Shouldn't Their Language Be Used? -- You have been trained in the operation of fire alarm systems, your customers have not... Read More

Does Anyone Return to Make the Installation Look Good? -- My father-in-law once told me "Make it purdy the first time; you'll always come back to make it work, you'll never come back to... Read More

How Does One Gain Experience? -- If every time one goes on site to fix the fire alarm system the problem is obvious, being a troubleshooter... Read More

Is the Sense of Time Important in Troubleshooting?-- Sometimes, when servicing fire alarm systems to find the troubles, one has to use all the common senses available to observe more than just... Read More

Can Stopping to Look at the Panel and Think Save Time? -- Sometimes, even after a lightning storm, what seems like a whole gaggle of troubles, is really only a few small troubles... Read More

What is a Friday Afternoon Repair? -- If the fire panel shows normal, you may never get back to fix a trouble; if the fire panel shows trouble, you'll always come back to...Read More

Why Use a Cheap Meter when and Expensive Meter is Better? -- Like a doctor always carrying a stethoscope, so should a technician always carry a... Read More

When Should Fire Alarm Batteries Be Replaced? -- The 2007 NFPA72 shows in Table 10.4.4, Item 6(d)(1), that the sealed lead-acid batteries used for battery backup in fire... Read More

Why are Battery Date Codes so Cryptic? -- For safety reasons, the NFPA Code requires the replacement of fire alarm batteries within 5 years of manufacture...Read More

Do You Have to Replace Fire Alarm Batteries in Pairs? -- The question is asked: In a fire alarm system, where backup batteries are wired in series, can the batteries be changed out one at a time, or do the batteries have to be changed out in pairs? Remember that the... Read More

Are As-Built Drawings Available When Needed? -- When available, as-built drawings are used by architects and engineers for remodeling or for designing new additions to... Read More

How Does One Remove Tarnish from Electronic Contacts? -- Has this ever this happen to you? The electronic circuit you're servicing isn't working. You take it apart, look at it, and... Read More

What is a Ground Fault? -- With the exception of the ground fault circuitry inside the fire alarm control panel (FACP) itself, the wiring for fire alarm systems has... Read More

How Does One Find a Soft Ground Fault? -- Normally, we think of resistance like that of a resistor. The amount of resistance is built-in; no matter what voltage is used to drive the electrical... Read More

Why Do Ground Faults Keep Happening in Some Buildings? -- Someone on a condominium board wrote about recurring ground fault issues with his building. Some of the other board members... Read More

Can Low Tech Follow-the-Wire Help Troubleshoot? -- Someone once said "Experience is something you gain when things go wrong." Well, wiring issues are things that have gone wrong, and a lot of experience... Read More

How Does One Keep Track of All Those Wires? -- Changing a circuit board, whether it's in a fire alarm panel, a security panel, a card access panel, or some other panel, can be a potential nightmare if a mistake is made and the wires are mixed up. Read More