Itm Fire Alarm

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Fire Detection and Alarm Systems

Section I: Inspection, Testing and Maintenance Requirements

Quarterly Frequency (4-times per year)

Initiating Devices – Flame Detectors

Inspection Check that detector is free from physical damage, securely mounted and

operational. Verify the detector is properly located and the field of view is unobstructed. Inspect the detector lens for cleanliness.

Initiating Devices – Supervisory Devices

Inspection Check that supervisory device is free from physical damage, securely

mounted and operational. Supervisory devices include: Control ValveTamper Switch, Air Pressure Switch, Room Temperature Switch, Water LevelSwitch, and Water Temperature Switch.

Testing Operate valve or switch of each supervisory device and verify receipt of signal.

Exception: Valve Tamper Switch may be tested less frequently. (see semi-annual Inspection, Testing and Maintenance requirements)

Maintenance Adjust supervisory device (if field adjustable) to operate at the approved set-

point when required.

Initiating Devices – Waterflow Devices

Inspection Check that waterflow device is free from physical damage, securely mounted

and operational.



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Semi-Annual Frequency (2-times per year)

Control Equipment

Inspection

Check batteries for tightness of connection and to be free of any corrosion or leakage. Validate all control unit trouble signals and repair all necessary fault conditions Verify transient suppressors are in normal condition (also inspect after any

lightning strike)

Testing Test for proper operation of the batteries under load. Disconnect the battery

charger, operate system under maximum load and measure the batteryterminal voltage. Ensure the voltage doesn’t fall below the specified level.

Emergency Voice / Alarm Communications Equipment

Inspection Verify all emergency voice / alarm communications equipment (amplifiers,

microphones, firefighter telephones, etc.) are in normal operating condition Visually inspect all phone jacks

Initiating Devices – Smoke Detectors


operational (LED is flashing). Verify the detector is properly located and unobstructed. Inspect the detector exterior for dirt and dust accumulation

Initiating Devices – Heat Detectors


operational (LED is flashing). Verify the detector is properly located and unobstructed.



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Initiating Devices – Manual Pull Stations

Inspection Check that Manual Pull Station is free from physical damage and securely

mounted. Verify the Manual Pull Station is properly located, unobstructed and accurately

identified. Verify that extinguishing system agent release stations are of the dual-action

type and properly identify the suppression hazard zone.

Initiating Devices – Flame Detectors

Testing Perform functional test in place to ensure alarm response. (typically a

manufacturer approved radiating light source) Test sensitivity using a method approved by the manufacturer.

Maintenance Clean detector lens when required. Adjust sensitivity (if field adjustable) to be within the approved range when

required.

Initiating Devices – Supervisory Devices

Testing Operate control valves to activate tamper switch and verify receipt of signal.

Maintenance Adjust valve tamper switch to operate at the approved number of valve

revolutions when required.

Initiating Devices – Waterflow Devices

Testing Water should be flowed to activate waterflow device and verify receipt of

signal. (see NFPA 25 for detailed requirements)



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Maintenance Adjust waterflow device to operate at the approved flow rate (see NFPA 25 for

detailed requirements)

Digital Alarm Communicator Transmitter (DACT)

Inspection Verify equipment has no physical damage and is in normal operating condition Check that two separate phone lines are connected and that both are loop

start type lines.

Annual Frequency (1-time per year)

Control Equipment

* Note: The frequencies and tasks in this section are for control equipment that is monitored for Alarm, Supervisory and Trouble signals. See NFPA 72, Table 10.3.1 & 10.4.3, 2002 Edition for details on unmonitored control equipment.

Inspection Verify equipment has no physical damage, is unobstructed and is in normal

operating condition Check all fuses for proper size and proper installation

Verify all interfaced equipment (interconnected control panels) is in normaloperating condition Illuminate all lamps and LEDs on all control panels and annunciators. Check for normal indication of the primary power supply Check all fiber-optic cable connections are free from physical damage and

connected properly

Testing Perform functional test to verify the control panel and annunciators correctly

receive alarm, supervisory and trouble signals. If signals are transmitted to anoff-premises location, also verify the receipt of these signals at that location.

Perform functional test to verify the control panel will properly operate theevacuation signals and auxiliary output functions.

Test for supervision of control panel circuits. Verify the detection of opencircuits and ground faults for each circuit.

Test smoke detector circuits that use alarm verification features for time delayand alarm response.



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Test the disconnect switches of the control panel to verify performance of intended function and receipt of a trouble signal.

Test for supervision of power supply. Verify the detection of loss of AC power and disconnection of batteries.

Test for supervision of control panel fuses. Verify the detection of loss of fuseand for the proper rating.

Test the integrity of the communications between two or more control panels

by simulating or operating the units to see that the required signals aretransmitted to the control panel. Test under both primary and secondarypower.

Test all functions and features of multiplex systems to operate according todesign documents, circuit styles and manufacturer specifications.

Test each primary power supply by disconnecting the secondary power supply(batteries) and operating under maximum load.

Test each secondary power supply (batteries) by disconnecting the primarypower supply and operating under maximum load for a minimum of 5 minutes.(Emergency Voice Communications Systems for a minimum of 15 minutes).Verify the occurrence of a trouble indication for loss of primary power.

Check for proper operation of the battery charger by measuring the batteryvoltage to ensure it is within a proper range as specified by the manufacturer of the control panel. The batteries should be fully charged and connected tothe charger during this test.

Allow the batteries to discharge for a period of 30 minutes. Load test thedischarged batteries and measure the battery terminal voltage. Ensure thevoltage doesn’t fall below the specified level.

Test fiber-optic transmission lines to verify power level hasn’t dropped below2% of the initial acceptance test value.

Maintenance Clean battery terminals or connections if needed. Replace battery within 5 years of manufactured date or sooner if battery

voltage or current falls below manufacturer recommendations.

Emergency Voice / Alarm Communications Equipment

Testing Test amplifier and tone generators for correct switching functions. If provided,

also verify the proper operation of backup equipment.

Verify indication at control panel of phone removed-from-hook or phone setinstalled at phone jack. Test the communication path through all phone jacks and activate each phone

set to verify correct operation. Test for total system performance. Verify voice quality and clarity is at an

acceptable level. Include in this test the simultaneous operation of at least 5handsets.



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Initiating Devices – Smoke Detectors

Testing Perform functional test in place to ensure smoke entry and alarm response.

Test sensitivity using a method approved by the manufacturer. (only whenrequired; see NFPA 72-2002 10.4.3.2, typically every 2 years) Test duct detectors to ensure they will sample the air stream. Test detectors with control output functions. Verify the operation of the output

when all other initiating devices on the same circuit are in the alarm state.

Maintenance Clean detector using a method approved by the manufacturer (only required

for detectors with sensitivity out-of-range)

Initiating Devices – Heat Detectors

Testing Restorable Heat Detectors: Perform heat test in place using a heat source to

ensure response within 1 minute. Only two (or more) detectors on eachinitiating circuit must be tested annually, and different detectors must be testedeach year such that within 5 years each detector has been tested.

Non-Restorable Spot Heat Detectors: Do not perform heat testing. Testfunctionality both mechanically and electrically.

Non-Restorable Linear Heat Detectors: Do not perform heat testing. Test

functionality both mechanically and electrically. Measure loop resistance andverify it matches the recorded value from initial acceptance testing.

Maintenance Non-Restorable Spot Heat Detectors: Replace all detectors every 15 years

(optionally laboratory testing method can be used if desired)

Initiating Devices – Manual Pull Stations

Testing Operate all Manual Pull Stations according to the manufacturers

recommendations.



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Alarm Notification Appliances

Inspection Check that all notification appliances are free from physical damage, securely

mounted and unobstructed. Verify the location of visual appliances are to be in accordance with the

approved layout and that no Floorplan changes have affected the layout. Verify the candela rating of visual appliances to be in accordance with

approved drawings.

Testing Measure and record the maximum sound pressure level output when the

emergency evacuation signal is on. Levels throughout the protected areashould be measured and recorded. An approved meter must be used (seeNFPA 72, table 10.4.2.2. - 14a)

Speakers used to convey voice messages should be verified to produce

audible information that is distinguishable and understandable. (see ANSIS3.2 for appropriate methods)

Check that all visual appliances (i.e. strobe light) will flash.

Digital Alarm Communicator Transmitter (DACT)

Testing Test that the activation of an initiating device will produce the appropriate

signal at the supervising station within 90 seconds of activation. Test for line seizure capability.

Test proper operation of primary line while secondary line is disconnected.Verify trouble signal is received by receiving unit within 4 minutes of disconnect.

Test proper operation of secondary line while primary line is disconnected.Verify trouble signal is received by receiving unit within 4 minutes of disconnect.

Test for proper transmission to secondary phone number while simulating afault in the primary phone number.



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Section II. Explanatory Material

General

A building or local fire alarm system provides audible and/or visible alarm signals as the result of the manual operation of a fire alarm station, the automatic operation of a fire detector, such as asmoke or heat detector, or the automatic operation of protective equipment, such as a sprinkler system. Audible and/or visible alarm signal devices are commonly known as notificationappliances. Manual stations, waterflow switches, pressure switches and fire detectors arecommonly known as alarm initiating appliances.

Usually the system consists of fire alarm manual stations, located at stairs or exits, with notificationappliances in corridors and larger rooms so that all occupants can hear the alarm signal when thesystem is activated. Manual stations, detectors, waterflow devices or audible alarms are connectedto a fire alarm control panel by electrical wiring, which is supervised for continuity. The supervisionis performed by passing a small current through the wiring and monitoring the current received at

the control panel. If the current is not received at the control panel, a trouble signal is sounded.

Fire alarm circuits can be arranged to operate under normal, open or ground conditions, dependingupon the sophistication of the system. Details on these types of circuits are contained in NFPA 72,Standard for the Installation, Maintenance and Use of protective Signaling Systems, - and NFPA72H, Guide for Testing Procedures for Local, Auxiliary, Remote Station, and Proprietary ProtectiveSignaling Systems. Style A, B and C circuits allow the fire alarm system to be operated with asingle break in the wiring for all manual stations, detectors and waterflow switches closer in thecircuit to the control panel than the break. Style D and E circuits allow fire alarm systems to be fullyoperational with a single break in the wiring, regardless of location of the break.

Alarm notification appliance circuits are arranged in a similar manner as the initiating devicecircuits. Circuits on which appliances closer to the control panel than a single break will operate areknown as Styles W or Y circuits. Those circuits on which all indicating appliances will operateregardless of the location of the single break are known as Styles X or Z circuits.

Three methods are commonly used to notify building occupants through the fire alarm system. Themost commonly used is the general alarm method. With this type of system, all alarm indicatingdevices are operated throughout the building. The selective method operates only those indicatingdevices on the floor or in the fire area in the vicinity of the manual station, detector, waterflowswitch or other initiating device which has actuated the fire alarm system. The third method is apre-signal system, which sounds an alarm only at the fire alarm control panel or constantly

attended location within the building and requires that someone investigate the fire. If the firerequires evacuation of occupants, the investigator causes the alarm signals to sound by inserting akey into the fire alarm manual station or initiating the general evacuation alarm at the control panel.Pre-signal systems are not allowed in some occupancies by NFPA 101, Code for Safety to Lifefrom Fire in Buildings and Structures (commonly referred to as the Life Safety Code).



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Alarm signals can be continuously ringing, march time or coded type. Continuously ringing andmarch time bells sound an alarm until the fire alarm system is reset at the fire alarm control panel.Coded bells usually sound three or four rounds of code and then stop.

Emergency power can be provided for any fire alarm system and is often required by the applicablecodes. This usually consists of either an emergency generator or a battery charger with batteriesand perhaps an inverter.

For larger systems, the location of the manual fire alarm station, fire detector or flow switch whichhas activated is annunciated. Usually this is done by grouping similar initiating devices for a floor or a fire area into a zone. For example, fire alarm manual stations on the second floor of a buildingcould be grouped into a zone known as “second floor manual station.” For continuously ringingsystems, this annunciation usually consists of light bulbs or light emitting diodes (LED’s) at anannunciator panel, labeled to indicate the alarm location. For coded systems, this most oftenconsists of a decoder or a punch tape with a time clock stamp.

Two-way communications systems consist of telephones or plug-in devices for talking back andforth to an emergency command center. Such devices are usually located in the command center

and in or adjacent to stairways, elevators, and elevator lobbies.

Supervisory device circuits are connected to sprinkler control valves, standpipe valves or other components which must be in their normal operating position in order for the system to operateproperly in an emergency.

Alarm Initiating Devices

There are many types of initiating devices. They are briefly described below. A fire alarm systemmay have one or more types depending on the hazard and the level of detection required.

Manual Stations

Manual stations are electric switches usually covered with a red-colored housing and located near exits. Manual stations generally have an indicating feature so that the station that was activatedcan be easily recognized. Some manual stations use a break-glass rod or other breakable featurewhich is broken upon activation. Other type stations are designed so that the face of the stationmust be reset after activation. Resetting is generally accomplished by use of a key, screw driver, or allen wrench.

Manual stations can be of the single action type requiring just one motion to activate or doubleaction type requiring two motions to activate.

Smoke Detectors

Smoke detectors are devices provided on fire alarm initiating circuits to automatically detect fire bysensing smoke particles.



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Ionization type detectors contain a small amount of radioactive material that ionizes the air in thesensing chamber. The ionized air in the sensing chamber conducts electricity between two chargedelectrodes. When smoke particles enter the chamber, they decrease the conductance of the air.When this conductance falls below a predetermined level, the detector indicates an alarmcondition.

Photoelectric smoke detectors utilize either of two principles of operation. One method - light

obscuration - has a light beam which continually strikes a photosensitive device. As smokeparticles enter the chamber, the light reaching the photosensitive device is reduced, initiating analarm. A second method - light scattering - has a light source and a photosensitive device. Lightfrom the source does not usually strike the photosensitive device; however, the light is scatteredupon striking any smoke particles that enter the chamber. Some scattered light strikes thephotosensitive device, which initiates an alarm.

Some photoelectric smoke detectors utilize a cloud chamber for determining the presence of smoke. An air pump draws a sample of air from a protected area into a high humidity chamber within the detector. The pressure is lowered slightly within the detector after the sample hasentered the chamber. This causes the moisture to condense on any smoke particles, which forms a

cloud within the chamber. If the density of the cloud exceeds the alarm level, the detector initiatesan alarm.

Some photoelectric smoke detectors utilize a projected beam concept. A light source is projectedacross a space and received by the photoelectric smoke detector. In the event of a fire, the smokereduces the light received at the detector, initiating an alarm via the light obscuration principle.

In addition to being located on or near ceilings, some smoke detectors are designed for use inductwork. These duct smoke detectors are meant to shut down the air handling system to preventrecirculation of smoke in a building.

Smoke detectors have been a source of significant but needless alarm problems. The test criteriafor the listing of smoke detectors was changed between 1980 and 1985 which caused an increasein detector sensitivity. This made the units susceptible to needless activation from excessive air movement, low levels of products of combustion, and dirt/dust conditions. In January 1985,manufacturers were allowed to increase the level of smoke obscuration causing a smoke detector to activate. Another solution being used to reduce needless alarms is the installation of verificationmodules within the fire alarm control panels. With these modules, an alarm is received from asmoke detector but the information is stored within the control panel for a limited period of time andthe smoke detector circuit is cleared. If the smoke detector goes into alarm again during thereconfirmation period, a fire alarm is initiated. These two features are drastically reducing theneedless alarm problem.

Heat Detectors

Heat detectors are devices provided for the automatic detection of heat from a fire. Heat can bedetected by fixed temperature, rate-of-rise or rate compensation devices.



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The simplest type of heat detector is the fixed temperature type. It consists of a detector housingcontaining a fusible element that melts rapidly at a predetermined temperature. The elementmelting causes electrical contacts to operate which in turn initiates an alarm on the fire alarmsystem.

Rate-of-rise detectors can be either electric or pneumatic. An electric detector consists of adetector housing, a diaphragm within the housing, and a small vent hole to allow expansion and

contraction of air in the housing due to small temperature changes. Heat from a fire causes the air within the detector housing to expand more quickly than it can be vented. This expansion createspressure on the diaphragm that operates electrical contacts.

A rate compensation detector responds when surrounding temperatures reach a predeterminedlevel, regardless of the rate of temperature rise. Similar to a fixed temperature detector, it is faster acting. It has two internal metallic elements which expand toward each other when heat isdetected. Upon touching, the electrical contacts complete the circuit and cause activation of thealarm panel.

Flame Detectors

A flame detector responds to radiant energy either within or outside of the range of human vision.Flame detectors are available which are sensitive to the glowing embers, coals or actual flames of fire. Outside the human range of vision, flame detectors are infrared, ultraviolet, or combinationtype. Within the human range of vision, spark / ember-sensing and photoelectric flame detectorsare available.

Since these detectors are extremely sensitive, they are often subject to needless alarms. For thisreason, they are used primarily in areas in which explosions or very rapid fires might occur andwhere immediate detection is needed.

Infrared detectors have filters and a lens system to screen out unwanted wavelengths.Nevertheless, they still have a major problem with interference from solar radiation in the infraredregion.

Notification Appliances

Audible Alarm Appliances

Bells and horns are commonly used devices that generate loud noises to indicate an emergency.Audible notification appliances must be heard in all occupied areas. To make sure audible alarmappliances are heard it is recommended that their sound level be at least 15 dba above thebackground sound level or 5 dba above the maximum sound level having a duration of 60 secondsor more.

A bell consists of a metal dome, a coil, and a plunger. Most bells have an adjustment screw for varying the striking force of the plunger. In many new fire alarm systems, bells are polarized sosupervision can include each individual bell in addition to the circuit to which it is connected.



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Polarization is achieved by a diode within the bell. Supervision for individual bells is dependentupon the way the bell is connected to the circuit.

Horns consist of electromagnets which vibrate a steel diaphragm. Most horns have an adjustmentscrew for varying the sound level output. A horn, like a bell can be a polarized type, with asupervisory diode within the unit.

Loudspeakers are used with voice alarm systems. Older systems may have used standardspeakers wired in series. Newer systems use supervised speakers with transformers andcapacitors wired in parallel, as required by NFPA standards. The transformers in parallel wiredspeakers have multiple taps of various wattage ratings from varying speaker outputs. The sum of the speaker wattages for each speaker circuit cannot exceed the total wattage capacity of thatparticular circuit.

Visible Alarm Appliances

Visible alarm devices have been used in areas where hearing impaired persons may be located.The 1991 Life Safety Code, and the Americans with Disabilities Act (ADA) now require visible

alarm devices on all new fire alarm systems. Visible alarm devices can consist of a variety of lamptypes, such as rotating lights or flashing strobe lights.

Design Requirements

Design and Installation requirements can be found in the following codes and standards:

NFPA 72, National Fire Alarm Code

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