Fire Alarm Systems 101 Q&A
PSI recently held a webinar focused on the foundations of fire detection and alarms. Our presenters shared information on fire alarm terminology, commonly used acronyms, codes and standards, and the basics of fire alarms. Attendees left with a greater understanding of fire detection and alarm systems required by today's codes. If you weren't able to attend, you can still watch a recording of the Fire Alarm Systems 101 Webinar here.
You may find access to the Glossary of Fire Alarm and Mass Notification Terminology helpful—also referred to throughout the webinar.
Several great questions were asked during the presentation, and we wanted to provide the answers for everyone to reference. Please find the Fire Alarms Systems 101 questions and answers below.
At PSI, our factory-trained and NICET-certified technicians provide comprehensive fire and life safety services—monitoring, testing and inspecting, system maintenance, installations, and code compliance consultations—all under one agreement. Contact us today to schedule your free consultation.
When considering panel messages (Alarm, Supervisory, and Trouble)—how do you decide what is worthy of calling for immediate help vs. waiting until the next day?
As you can imagine, alarms will require immediate attention. Supervisory conditions are most likely to happen on purpose (like when your sprinkler system is being serviced). If you get a Supervisory at night, it is most likely important enough to call for service immediately.
For the most part, all changes to a fire alarm from its normal state are important. A couple of Trouble conditions, like a "low battery" or "dirty detector" might be put off until the next day, but this decision should be made by someone that understands the potential hazards.
Next time you have PSI out to do an inspection or service call, ask us to spend a few minutes talking about the specifics of your building and system. Our technicians can share their experiences.
Are there ways to turn the sound off for Trouble alarms—to not be a nuisance in public places?
Most modern alarm panels have condition indicators for alarm, supervisory, and trouble conditions with an associated LED and silence button. Since alarm conditions are required to lock in, a reset button is provided for that purpose. It is important to note that you should only operate a fire alarm panel if you are knowledgeable and the one authorized to silence the condition.
Alarm conditions should be investigated by the fire department prior to silencing or resetting. Supervisory and trouble conditions are an indication that the system may not perform as designed in the case of a fire. They should both be taken seriously and attended to by competent personnel promptly.
Heat alarms are often connected to sprinkler systems. Does a heat detector Trouble need to be audible outside the building?
It was stated that a sprinkler system being monitored, through the use of flow and tamper switches, by a fire alarm panel does not constitute a fire alarm system. This can be done without introducing the need for building occupant notification.
If area heat detection is also connected to the panel, building occupant notification is required. The only activation of the system that requires an external notification appliance is the flow of water unless mandated by the local AHJ. All system condition changes should send a signal to the central station in order to dispatch the appropriate personnel.
How can HVAC systems be maintained to ensure duct detectors do not have nuisance Trouble alarms?
The current code requires periodic sensitivity testing of all smoke detectors. Some detectors have the ability to perform this test electronically, without special test equipment. This test should indicate if the detectors need cleaning. Duct detectors that use sampling tubes should also have the differential pressure between the sampling and exhaust tube tested to ensure proper sampling of the air flowing through the ductwork.
Periodic maintenance of the HVAC system, including the cleaning or replacement of filters, should be accomplished by qualified personnel and may help prolong the time between detector cleaning or replacement. Nuisance alarms sometimes occur during the time when an HVAC system has been set dormant for some period of time, causing dust to collect in the system and on the heating element. In a normally active HVAC system, this sort of thing is rare with proper maintenance intervals.
Do fire alarm panels in locations behind locked doors need to be accessible to the fire department to find the location of the fire alarm?
The fire department should have access to fire alarm annunciation in order to quickly identify the origin of the alarm. Many communities use external lock boxes that are only accessible to emergency responders for this purpose. The fire department has special tools and doesn't hesitate to use them, to gain access to the building if they think it's on fire.
Can you explain what an annunciator is?
Annunciator: A visual and/or audible system component that indicates an alarm or other condition. Annunciators are typically located at building entrances or at emergency control locations. May consist of LEDs, and/or LCDs and may take the form of a graphic representation of the building. Annunciators may also incorporate features such as system common controls, auxiliary fan and damper controls, and paging controls.
Who is required to inspect as-builts drawings to ensure the as-builts correlate correctly with fire alarm addresses in the panel CPU?
The ultimate responsibility of having and maintaining accurate and useful as-built drawings rests with the owner of the building. Owners often trust these to architects, engineers, contractors, and consultants. It is not unusual for an architect to design a building using a number of designations for building areas, including rooms, exit corridors, etc.
It is likely, as the building moves from construction to occupancy and use that these number of designation change to more common names. The owner will benefit from anticipating this change and engage with the construction team early in the process in order to have the system programming match the intended final nomenclature. Sometimes general contractors are threatened by this early introduction of the owner and fire alarm contractor but would be better off encouraging this relationship sooner rather than later.
After all, once the project is complete the fire alarm supplier will likely be the one providing inspection and test services. It is an unnecessary expense for the owner to pay to change names that could have been done correctly in the first place.
Why do some fire alarm pull stations have a plastic tab inside the box that breaks when the pull station is put back to its normal position?
The plastic or glass rod that is installed in many manual stations does two things. It provides a small amount of resistance to prevent the accidental activation of the device—and keeps the person that activated the device from restoring it to a normal-looking condition that might confuse the investigation of the event.
Do larger amp-hour batteries allow emergency power to last longer? Is it ok to install larger amp-hour batteries in fire alarm panels if they physically fit?
Batteries with a larger amp-hour rating will provide longer support times during a power outage. Assuming they physically fit inside the cabinet, the only other consideration is the ability of the system charger to charge the higher amp-hour battery.
When would an alarm vs. a speaker strobe be required? If a strobe is in the ceiling what are the visual requirements for that strobe?
Once a building is determined to require a fire alarm system, building occupant notification is also required. Sound volume and audibility are defined by the code and determined by engineering evaluation based on the expected ambient noise levels for the occupancy and are provided by installing horns or speakers. The building's structure and materials will affect the number and location of devices required to achieve the necessary levels.
Strobes are required in all public areas and areas occupied by persons with hearing disabilities. Strobe coverages are defined by the code as well and may be either wall or ceiling mount. NFPA 72 provides guidance on the proper placement and Candela rating required to cover various conditions. It is important to use devices that are specifically designed and listed for ceiling or wall mount. The coverages are quite different.
Are automatic detectors an applicable replacement for smoke detectors? Are these common or more expensive?
Smoke detectors are a type of "automatic" detector. Smoke detection can be accomplished in a number of ways and manufacturers provide a number of devices from the basic optical chamber (spot type) to highly sensitive air aspiration detection systems. Pricing fluctuates with the technology and generally increases as faster responses are provided with better immunity to unwanted alarms.
Can we change the recording voice in the emergency message when the power goes off?
The automated message that is played by a voice evacuation fire alarm system is subject to approval by the AHJ, usually the Fire Marshal's Office. Fire alarms may be outfitted to provide a single message during a fire event or multiple messages based on the location or building features, even in multiple languages. In those systems that are sophisticated enough to provide custom messages, you could theoretically have one specifically for a power outage. However, the configuration would have to be submitted and approved.
Is there a requirement for testing smoke evacuation systems? Is there a requirement to have a licensed individual(s) perform the required testing of dampers or exhaust systems?
Yes. Smoke control systems do require periodic testing along with all smoke doors and dampers. NFPA 105 and 92 drive the requirements.
I have a campus with the main building housing educational programming and the second building is our gym. Does the fire alarm need to be tied in together?
If these are considered two separate buildings, they would not generally require interconnection unless the local AHJ requires it.
Has the AHJ given more flexibility with occupancy classifications with square footage for companies that continue to allow employees to work from home?
We've seen no particular requirements based on the issues that arise from building occupants working remotely. If additional rooms are built in order to accommodate these issues it would likely require additional notification, both audible and visible.
We have a campus of empty buildings that are scheduled for demolition. Do we have the ability to request a variance or exception with the AHJ/City if we do have sprinkler coverage, but there are no occupants?
This seems like a legitimate way to bridge building protection until demolition. PSI may be able to help survey and propose the interim solution. A functional sprinkler system, monitored by a fire alarm with central station communication abilities would be key.
We hope you find the recording of the Fire Alarm Systems 101 Webinar and the Q&A above helpful. At PSI, our NICET-certified technicians provide services considered by our customers to be best in class. Contact us today for a free consultation on your fire and life safety systems.