This FAQ is intended to help provide some information related specifically to fire alarm systems and detection devices.

 

Building fire alarm systems usually consist of a common control (mounted in a metal box), manual pull stations at every exit door, smoke detectors in the hallways, and some means of audibly and/or visually notifying the occupants of the building that an alarm has occurred. The audible signals can consist of bells or buzzers, but in some systems, an alarm tone is generated through a series of speakers located on each floor of the premise. Where hearing impaired patients or occupants are located, it is usual to have strobe lights located along corridors and in individual rooms that indicate a fire exists in the building.

The common control employs several features to enable the occupants to identify problems within the system. Correction of any troubles should be left in the hands of a fire alarm service company. Most fire alarm systems employ "zoned" annunciators so that fire fighting personnel can be dispatched to the proper area of the building.

There are several different manufactures of building fire and evacuation type systems. Here are a few of the more common ones. We've provided links to some of the manufacturers so you can investigate their equipment and services.

 

 

Daily Testing - is the responsibility of the building management or an individual they've designated to perform these duties. They include:

• Checking to ensure that there is no large accumulation of combustible material, rubbish or flammable liquids;

• Checking to ensure that all the exit signs are in good order, and that adequate lighting in the public corridors and stairwells is maintained;

• Checking to ensure all the fire doors operate properly and that none are wedged in the "OPEN" position (doors equipped with automatic closers or hold open devices are an exception as they will close when the building's fire alarm is sounded);

• Checking all the exit routes remain free from obstructions;

• Checking to ensure all fire hoses and extinguishers are unobstructed, in good order and ready to use;

• Checking the fire alarm control panel to ensure it is free of obstructions, any glass paneling is clean, the locks have not been tampered with, the "AC POWER" indicator is "ON", and that the system is trouble free;

• Checking corridor and public area fire and smoke detectors, pull stations, audible and visual appliances (bells, horns) to ensure they are clean, undamaged, and unobstructed.

Monthly Testing - Requires the building management or designated individual to actually initiate a fire alarm by activating one of the building's pull stations. You can download the monthly test record in either Word or WordPerfect format. It's usually a good idea to post the date and time of the test so that tenants/occupants are aware of the situation and won't be unduly alarmed. It might be a good idea to suggest that they practice their individual escape plans during the test. The monthly test is to ensure that all audible and visual alarm indicators function properly and are loud (or visible) enough to alert all the occupants to a fire condition.

In addition to this test, the designated individual should also ensure that he responds to issues and concerns expressed to him by the tenants/occupants with regard to the operation of the fire alarm system.

Annual Testing - The Annual Test of the fire alarm system is performed by qualified technical personnel to a specific standard (in Canada it's called ULC CAN4-S536 The Standard for the Testing of Fire Alarm Systems). There are a number of companies in the Lower Mainland (where I live) that perform this service. In some municipalities (Vancouver, Richmond, and Langley), the individuals performing the test must be certified by A.S.T.T.B.C. The test report must be submitted to the building owner's representative in a format approved by the local authority.

The Verification - Verification of a fire alarm system must take place when the system is first commissioned and is one of the final steps to obtaining an occupancy permit for the building. In Canada, the test is performed to ULC CAN-S537-97 Standard for the Verification of Fire Alarm Systems by the fire alarm system manufacturer, or an individual authorized by the manufacturer to perform the service. In some instances, the Electrical Design Engineer is involved in the process as well. This is the most rigorous of testing procedures the system will have to undergo in it's lifetime. Not only are individual devices tested for a variety of conditions (not just operation), each device in the system must be examined for proper "PLACEMENT". This ensures the pull station/smoke detector/heat detector/bell is installed in accordance with the manufacturer's instructions, the applicable building codes/bylaws, and ULC CAN-S524 (The Standard for Installation of Fire Alarm Systems).

In addition, a verification may be required if a device is replaced or added to the system. Please check with your local civic authority (Electrical Inspections or Planning) and follow their guidelines to ensure compliance of your system.

 

SMOKE DETECTORS

Smoke and fire detectors should be considered an integral part of any home or business security system. In most all instances involving fire, a smoke detector provides sufficient warning to the residents/occupants to enable them to evacuate the premises safely, notify the fire department, and minimize the damage to the structure and contents.  A security or fire alarm system that employs integrated smoke detectors is by far the best way to protect your family or workers.  In this instance the detectors are powered by a stand-by battery that will ensure continued protection even in the complete absence of electrical power or a "brown-out". Smoke alarms that are battery operated should have the batteries replaced every twelve months.  It's a good idea to mark the replacement date on a piece of masking tape and stick it onto the body of the detector.  Use only alkaline or lithium type batteries and make sure you double check the expiry date on the battery and test it before you place it in the unit.  Most smoke detectors installed today are wired directly to the household electrical system.  These units are vulnerable to electrical failures (they won't function in the absence of power).  Most house fires start in the electrical wiring so it's a good idea to have a battery operated smoke alarm installed as a "back-up". There are two types of smoke detectors (alarms):

Ionization type smoke detectors utilize a small source of radioactive material (usually Americium) that in fact ionizes airborne particulates and attracts them to to one side or the other of a polarized grid. When sufficient particles accumulate, the unit goes into an alarm condition. This type of detector works best for fast flaming fires that produce small amounts of smoke. It's also prone to false alarms when installed close to bathrooms or kitchens with older style dishwashers. Steam from your hot bath, shower, or operating dishwasher may accidentally "set-off" one of these units. It SHOULD NOT be used in a residential application as most home fires involve intense smoke.
Notice to users of Ionization type detectors - these sensors have a limited life of between ten and fifteen years. Check the date stamp located on the back of the detector. If in doubt, replace the unit and dispose of the old one in a safe manner.

Photoelectric type smoke detectors utilize an infrared light source (called the emitter) and a receiver, both of which are located inside the sensing chamber. Smoke particles obscure the receiver, and the unit goes into alarm. This type of detector is best used in residential applications, as it provides extremely good early warning to smoldering type fires that tend give off dense smoke and noxious fumes.

Regardless of the type of detector your residence or building employs, there's some additional maintenance you can perform to ensure the continued peak efficiency. Once a month or so, take your vacuum (on it's lowest setting) and utilizing a soft brush attachment, clean out the vents of the detector. Never paint the sensor! If the sensor is part of an actual fire alarm system, make sure you alert other tenants in the building as to what you're doing as well as your monitoring station (if applicable). There is a possibility that you may inadvertently set off the fire alarm system. Have someone standing by the panel so that they can cancel any alarm quickly.

Beam type smoke detectors are designed to protect a larger area (like atriums or corridors with very high ceilings). The principle of operation is similar to the photoelectric smoke detector described above. The unit consists of an "emitter" and a "receiver". Both "absorption" (smoke) and "scattering" (heat) of the infrared light from the emitter is detected as a signal loss at the receiver. This makes this type of detector extremely sensitive to both fast flaming and smoldering types of fires.

 

HEAT DETECTORS:

These are simple appliances that fall into the category of contact devices in that they employ two very basic and simple detection methods that don't involve complex circuitry or require a power source to operate (like smoke detectors). Straight heat detectors use a fusible link or disk that operates when the design temperature is reached. This is usually either 135 degrees or 200 degrees. Once triggered the unit has to be replaced (similar to a fire sprinkler head). Heat detectors are often referred to as fixed temperature detectors as well.

The rate-of-rise detector is also a member of this "family". It employs both a "fixed temperature" element and a resettable thermostatic element that is designed to close a set of contacts when there's a sudden significant change in temperature over a short period (usually around 15 degrees per minute).

Both these sensors require the presence of an open flame and as such are often labeled "not a life safety device". They're normally used in electrical vaults, closets, and storage rooms. In many jurisdictions fire sprinkler systems are recognized (and can be used) as "heat detectors" when tied to a listed fire alarm control. In this instance a water flow sensor would trigger the alarm, instead of the direct application of heat. There is an additional delay incurred in this instance because most flow switches have a retard function that prevents their immediate activation. This allows for slight changes in pressure in the municipal water supply (which can happen on occasion).

 

FLAME DETECTORS:

This type of unit is designed to sense infrared energy in a very narrow frequency band commonly referred to as the CO2 spike (which is between 4 and 5 microns - more specifically 4.45 microns). This type of detector is best suited to applications involving petroleum products processing, hazardous materials storage, fuel distribution and loading racks.

 

MANUAL PULL STATIONS:

Another of the contact device family. You'll find these units located by exit doors or along corridors that are termed "access to egress". Unlike the automatic detection devices mentioned above, this unit must be manually actuated to sound a fire alarm.

 

GAS DETECTORS:

Of the more common types, the CO (or carbon monoxide) detectors are one of the most popular for residential applications. You'll also see them utilized in underground parkades where they're controlling exhaust and fresh air fans to maintain safe levels of this very toxic odorless byproduct of the "infernal" combustion engine. There are other types of gas detectors available as well. Hydrogen, propane, natural gas, butane are all used to varying degrees in both commercial and institutional settings.

 

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