Why Separate Feed and Return Circuits on Class A?
-- Class A provides a redundant path. The redundant path is so that if the feed pathway is interrupted, like a wire breaking or coming loose from a connection, the redundant path becomes a Class B pathway to connect the devices beyond the interruption to the panel...Read More
Do I Assign Zones to NACs or NACs to Zones?
-- Firefighting zones and evacuation zones are an integral part of a building. Adding a fire alarm system doesn't change the zones, so the fire alarm system, including the notification circuits -NACs-, has to match the building's zoning and evacuation needs. Just be aware of the different kinds of zones, and what is really needed for the NAC...Read More
What does a Fire Alarm Saying Evacuation Not Required Mean?
-- The building is evacuated in stages. When the alarm first sounds off, those in greatest danger are told to evacuate the building. In essence, anyone on the floor of the fire, and those on the floors immediately above and below the floor of the fire, are told to evacuate the building...Read More
How do I Test the Fire Alarm System?
-- The testing a Fire Detection and Alarm System (FDAS) is to make sure all fires are detected, and when there is a fire, all occupants will be alarmed (Notified via sound and flashing lights). Most systems will also...Read More
Who has more Authority - NFPA or AHJ?
-- In the NFPA 72 Handbook, the writers basically say that if an AHJ wants something more stringent than what is shown in the NFPA 72 Code, we, as the designers, installers, and maintainers of fire alarm system, go with the more stringent requirements...Read More
Is Compatibility and Issue with Addressable Sounders?
-- The question -Do the sounders have to be compatible?-, can be reworded as -Do the sounders have to work with the panel, and with the other sounders on the circuit?- Compatibility is your assurance that the sounders -the horns, chimes, etc.-, and the strobes will work as advertised...Read More
Do We have to Provide Voltage Drop Calculations?
-- Voltage drop calculations, showing that enough voltage will be available to all the sounders and strobes, are your assurance that the sounders and strobes will work when there's a fire. Any circuit that the calculations haven't been performed on...Read More
What are the Requirements for Off-Site Monitoring?
-- For communicating signals off site, we are longer working with just DC signals or pules of AC signals, we also have computer style data being sent. The type of signal and method of carrying the signal can also change from one form to another along the same pathway. It may start out as a...Read More
Do I Have to Test All the Detectors?
-- When considering what needs to be tested to make sure the Fire Detection and Alarm System works, that the input devices do all the detecting, and the output devices do all of the alarming and protection from fires. The whole rest of the system, like panels and building wiring, is support equipment... Read More
Can We Trip a Booster Power Supply with an SLC?
-- This is an issue more concerned with compatibility than with the NFPA. However, to answer your question, we need some background information. NFPA - The Fire Code published by non-profit organizations like the National Fire Protection Association is published to show what a fire alarm system should be like when it is completed. Included with the... Read More
What is an Area of Refuge?
-- You hear the message "Use the Stairs, "you see the sign "In case of fire, don't take the elevator." To get out of the building from the higher floors, when the building is on fire, the stairs ... Read More
How are alarms hardwired to field equipment in a typical process plant?
-- I am a Process Safety Engineer but I am trying to understand alarms representation on a P & ID. I am sorry if this is not your area of expertise. Please, permit me to ask the following questions: 1. How are alarms hardwired to field equipment in a typical process plant like refinery, for example a high-pressure alarm monitoring pressure on a reactor or vessel? 2. How is the alarm hardwired such that the operator in the field as well as in the control room will be alerted? 3. Can an alarm be a field device that is not accessible to the operator in the control room? . . . Read More
Essential Fire Safety Tips For Landlords
-- On average, seven people die each day in U.S. home fires, the National Fire Protection Association reveals. As a property manager or landlord, keeping your tenants and property safe from fire is one of the most important responsibilities you have. Unattended ovens or cook-tops, smoking, portable space heaters, and electrical faults are the most common causes of house fires. Not only do property fires cause thousands of . . .Read More
How Clutter Can Increase Your Home Fire Risk
-- Official lists of the most common household fire risks include unattended cooking equipment, heating, broken electrical equipment, flammable liquids and even Christmas trees, but one aspect that can worsen all these risks and create a fire of its own, is clutter! NBC reports that one in four Americans has a clutter problem and 55% of those surveyed said it causes major stress. By keeping homes tidy, families can reduce their fire risk, but also reduce the frequency of falls and trips and the mental anguish of constantly being exposed to untidiness. . .Read More
How To Keep Seniors Safe From Fires
-- Did you know that closing your bedroom door at night could save your life? Studies show that, in house fires, carbon monoxide levels are ten times higher in rooms with an ... Read More
How Long can the Wire be to the Input Module?
-- The NFPA Code does not approve the exact wiring of the Initiating Device Circuit -IDC-. They also don't forbid any exact wiring of the IDC. They write legal code that can be used by governments; they don't design anything, including wiring for the IDC...Read More
Do we need horns and strobes in a building shell?
-- The NFPA Code is interpreted differently by different people, but to be a complete fire alarm system, the system must detect fire (the waterflow switch on the sprinkler system) and warn people of the fire (horns and strobes). This detect and warn includes the shell area because the shell area can be occupied... Read More
How do You Know if a Fire Alarm is Loud Enough?
-- I have been trying to obtain information pertaining to new audio / visual sound systems installed in our classrooms and what Fire Safety code -if any- mandates a requirement that the sound become shunted during an activated fire alarm. I have heard mixed statements but haven't been able to acquire any certain clarity...Read More
Can the Fire Alarm System use the Building Management Network Wiring?
-- If two systems, the fire alarm system and the building management and access control system, are combined, they have to be tested together. If they have been placed on the list (listed) by the testing laboratory as working together, then they are Compatible with each other. Almost always, compared to the building management system...Read More
Do I Have to Use Pull Station Glass Rods in a Daycare?
-- If the glass rod or plastic rod accidently broke, it might not be noticed right away. The broken pieces of rods would sit on the floor until they were vacuumed up. Personally, I wouldn't count on the vacuum cleaner finding the broken pieces before a crawling child got there to put the pieces in the mouth...Read More
Does the NAC Panel Power Source have to be Dedicated?
-- The FACP and the NAC Panel are part of the Fire Detection and Alarm System - it's a Life Safety System. If any of the system is turned off, some people will not be warned that there is a fire. If that happens, the building may burn down and people can be injured, or worse...Read More
Do the Lights have to Turn On if the FACP is in Trouble?
-- The National Fire Protection Association -NFPA- isn't a rule making authority, the NFPA is a non-profit publishing house. They gather people together to write guidelines showing the minimum needed to provide good fire protection, and then print some books... Read More
Do We Have to Get a Permit to Replace a Power Supply?
--Is it customary for a fire department to require a fire alarm modification permit to replace a remote power supply? We are replacing only one of the five existing with the exact same make and model. They tried to say - The fire alarm booster is ... Read More
Should a Hospital be Staged EVAC?
-- When it's a high-rise building, with only one fire zone per floor, the -Staged Evacuation- is usually interpreted as the fire floor, the floor above, and the floor below. However, when there are many zones per floor, the adjacent zones also have to be taken into account; the real staged evacuation system is the Zone of Incidence, and All Adjacent Fire Zones...Read More
Should a Hospital be Staged EVAC?
-- When there's an alarm, I believe that most of the hospital employees act as if the fire evacuation system is a -Defend-In-Place- system. For a hospital, rather than getting everyone out of the building if there's a fire, the patients are told to get behind a closed fire door. The alarm sounds off, though, as a -Staged Evacuation- system. With staged evacuation, when there's a fire, rather that totally evacuate...Read More
How does the Panel Decide if a Signal is Alarm or Supervisory?
-- The answer to the question of How does the system recognize is in the programming of the fire alarm system. That's at least for the Fire Alarm, Supervisory Alarm, and Monitor Activations. Troubles are hard-wired into the system - programming won't change anything about displaying a trouble. A fire alarm system doesn't really decide anything; a fire alarm system is told what to do through the program that is implanted into the system...Read More
Is the Fire Alarm Sounder Compliant?
-- In a fire alarm system, the term -Compliant- is a legal term meaning -It has been tested by a third-party, nationally known testing laboratory like UL, ULC, CE, CCC, FM, etc., and found to work in a particular fire alarm system.- The testing laboratory, if they have found it to work as a system then they will have -listed- as -Compliant- because they work together...Read More
Is a Whole Studio Apartment Considered a Sleeping Area?
-- The idea of having a low frequency horn in a sleeping area is to wake up a person, even an older or hard of hearing person, when there's a fire. In a Live-Work Studio, the sleeping area is less well defined than in a regular one- or two-bedroom apartment. From the tenant's point of view, the bed could be out in the open area of the Studio...Read More
Is the NFPA Code a List of Laws?
-- The reference to the NFPA 72 showing a List of Laws is not a reference to the NFPA as a rulemaking authority -they definitely are not-, the reference to the NFPA 72 showing a List of Laws is a...Read More
Does the NFPA Code Require Panel Replacement?
-- On the one hand, the NFPA publishes books that by themselves don't have any government rule-making authority. On the other hand, the books published by the NFPA are about the best description of how to protect from fires...Read More
What do they mean as Pathway on the Record of Completion?
-- The NFPA has now boiled down all the different Styles and Classes of the various signal pathways to a total of seven classifications. These classifications don't really show how to wire anything, these classes show how the building wide fire alarm system is going to work when something goes wrong with the alarm's communication routes. The pathways are now classified as Class A, Class B, Class C, Class D, Class E, Class N, and Class X...Read More
Does a Beam Detector Power Supply have to be Listed?
-- The NFPA Code does not list the requirements for a power supply on a beam detector, as such. However, the beam detector is a fire alarm system smoke detector. Because it is a fire alarm device, it is required to continue operating for as long as the fire alarm system is operating. To keep the beam detector working, the power supply...Read More
Does an Extra Monitoring Method Require a Permit?
-- Because these are minimum requirements, fire alarm systems can always be made better. Any Authority Having Jurisdiction -AHJ- can require more than the NFPA has shown in the legal code; sometimes the AHJ can just allow more than the NFPA has in the legal code. The NFPA itself talks about who qualifies as an AHJ...Read More
Should Security Guards Try to Put Out a Fire?
-- My personal suggestion to the security guards (you may wish to put this in their emergency response procedure book) is that if the alarms sound off, 1. Call the emergency response personnel right away. That starts the fire fighting process...Read More
Are T-Taps Allowed on a Class A SLC System?
-- With either Class A or Class B, if for any reason a device can't send or receive signals from the panel, the panel will show a trouble. Even if all devices communicate, a failure of the wiring also shows a trouble on the panel. Class B, when a wire breaks or comes loose, any devices still connected to the panel can communicate, but any devices past the break or loose connection can't communicate...Read More
How can I Learn and Understand the NFPA 72 Code Book?
-- Yes, the code needs to be complied with, but it is written so that lawyers, lawmakers, and those enforcing laws can understand it. The NFPA Code becomes easy to understand when you know what the intent of the Code is and some of the thought of the writers of the Code. That information is included in the NFPA's Handbook... Read More
What does SIL (Safety Integrity System) mean?
-- SIL -Safety Integrity System- is a confidence rating system. In some ways, it's similar in fire alarm systems to the classification system for signal pathways through the building -like Class A, Class B, C, D, E, N, X-. The SIL number is a measure of...Read More
The NFPA's Class of the Path
-- As a life-safety system, a fire alarm system detects fire and lets people know about the fire. That, though, is what the input and output devices do. Usually the fire alarm system includes with the input and output devices some sort of control system. This is the panel where the signals from ... Read More
Just Who Is the Authority Having Jurisdiction (AHJ)?
-- A.3.2.2 Authority Having Jurisdiction -AHJ-. The phrase authority having jurisdiction, or its acronym AHJ, is used in NFPA documents in a broad manner, since jurisdictions and approval agencies vary, as do their responsibilities. Where public safety is primary, the authority having jurisdiction . . . Read More