Fire Detection, Alarm and Suppression Systems FVCC Fire Rescue Fire Detection, Alarm and Suppression Systems

OBJECTIVES 2-18.1 Identify the types of fire alarm systems and their components (3-3.13) 2-18.2 Identify the value of automatic sprinklers in providing safety to the occupants of a structure 2-18.3 Identify a fire department sprinkler connection and water flow alarm

OBJECTIVES 2-18.4 Identify the main control valve on an automatic sprinkler system and determine if it is open or closed. 2-18.5 Identify how the automatic sprinkler head activates and releases water. 2-18.6 Identify the components of a hood and duct system and it’s use. 2-18.7 Identify wet pipe and dry pipe systems and their uses.

OBJECTIVES 2-18.8 Identify the procedures to connect hose line(s) to a fire department connection of a sprinkler or standpipe system. 2-18.9 Identify the procedure of stopping the flow of water from a sprinkler head using a wedge or stopper.

OBJECTIVES 2-18.10 Identify the procedure of operating a main control valve on an automatic sprinkler system from “open” to “closed” and then back to “open”. 2-18.11 Identify the procedures of opening and closing the main drain valve on an automatic sprinkler system.

OBJECTIVES 2-18.12 Identify the procedures of reading and recording the indicated pressures on all gauges provided on a standard wet pipe automatic sprinkler system and identify each gauge. 2-18.13 Identify the procedures of reading and recording the indicated pressures on all gauges provided on a standard dry pipe automatic sprinkler system and identify each gauge.

OBJECTIVES 2-18.14 Demonstrate connecting hose line(s) to a fire department connection of a sprinkler or standpipe system. 2-18.15 Demonstrate stopping the flow of water from a sprinkler head using a wedge or stopper. 2-18.16 Demonstrate operating a main control valve on an automatic sprinkler system from open to closed and back to open.

OBJECTIVES 2-18.17 Demonstrate opening and closing the main drain valve on an automatic sprinkler system. 2-18.18 Demonstrate reading and recording the indicated pressures on all gauges provided on a standard wet pipe sprinkler system and identify each gauge.

OBJECTIVES 2-18.19 Demonstrate reading and recording the indicated pressures on all gauges provided on a standard dry pipe automatic sprinkler system and identify each gauge. IFSTA, Essentials, 4th ed, Chapter 15 Delmar, Firefighter’s Handbook, 2000, Chapter 12

Fire loss in the U.S. and Canada U.S. Facts & Figures* (2001) Every 18 seconds, a fire department responded to a fire somewhere in the United States. Public fire departments responded to 1,734,500 fires. These include 521,500 structure fires, 351,500 vehicle fires, and 861,500 outside and other fires. In 2001, there were 6,196 civilian fire deaths; 2,451 of which were due to the events of September 11. Exclusive of the events of September 11, an estimated 3,745 civilian deaths occurred, a decrease of 7% from the previous year. In 2001, home fires caused 3,110 or 83% of civilian fire deaths, exclusive of the events of September 11. This is a 9% decrease, making it the second lowest home fire death total since NFPA´s fire experience current survey methodology started in 1977. Nationwide, there was a civilian home fire death every 170 minutes. Nationwide, there was a civilian fire injury every 26 minutes. There were an estimated 21,100 civilian fire injuries, of which 15,200 occurred in homes.

But the single-station, battery-powered smoke alarm we know today became available to consumers in the 1970s, and since then, the home fire death rate has been reduced by half. NFPA estimates that 94% of U.S. homes have at least one smoke alarm today, and most states have laws requiring them in residential dwellings. 15 of every 16 homes (94%) in the U.S. have at least one smoke alarm. One-half of home fire deaths occur in the 6% of homes with no smoke alarms. Homes with smoke alarms (whether or not they are operational) typically have a death rate that is 40-50% less than the rate for homes without alarms. In three of every 10 reported fires in homes equipped with smoke alarms, the devices did not work. Households with non-working smoke alarms now outnumber those with no smoke alarms. Why do smoke alarms fail? Most often because of missing, dead or disconnected batteries.

FIRE ALARM SYSTEMS & COMPONENTS Protected premises fire alarm systems (local) Most basic Designed to only be initiated manually

FIRE ALARM SYSTEMS & COMPONENTS Automatic alarm systems Transmits a signal to an off-site location to summon the fire department Produces an automatic response upon activation of local alarm Signals thorough dedicated wire pairs, leased telephone lines, fiber-optic cable, or wireless communication links

FIRE ALARM SYSTEMS & COMPONENTS Transmission of alarm to fire department may be accomplished by the following means: Auxiliary system – transmitted immediately and directly to the fire department. Uses municipally owned/controlled circuitry. 3 Types: Local Energy System, Shunt System, Parallel Telephone System. Municipal Master Box is an example of a Local Energy System

FIRE ALARM SYSTEMS & COMPONENTS Remote station system Connected to fire department directly or through an answering system Transmitted by leased telephone lines or radio signal on a dedicated frequency Must have the ability to transmit a trouble signal to fire alarm center, if system is impaired May be monitored by an entity other than the fire department A remote system must be capable of transmitting a trouble signal if the system is impaired

FIRE ALARM SYSTEMS & COMPONENTS Proprietary system Used to protect large commercial or industrial buildings or multiple buildings at a single location Each building or area has own alarm system wired to a single receiving point located within the complex Receiving point must be in separate, non-hazardous area Must be constantly staffed by trained personnel Monitoring personnel must be able to summon fire department through alarm system or by phone

FIRE ALARM SYSTEMS & COMPONENTS Central station system Similar to proprietary system but monitored off-site contracted service point called a central station Upon alarm initiation, central station employee obtains information and notifies appropriate emergency response agency Usually includes notifying fire department and property representative Usually connected by supervised telephone lines

FIRE ALARM SYSTEMS & COMPONENTS Four basic types of automatic alarm-initiating devices Heat detectors Fixed temperature heat detectors Relatively inexpensive Least prone to false activations Detect heat by: expansion of heated material, melting of heated material and changes in resistance of heated materials

FIRE ALARM SYSTEMS & COMPONENTS Types: Fusible Devices/ Frangible Bulbs Continuous Line Detector Bimetallic Detector

Fusible Fixed Temperature Heat Detector

Insulations loses some of its resistance at a predetermined Detect Heat over a linear Area parallel to the detector Insulations loses some of its resistance at a predetermined temperature anywhere along the line. This causes current flow between the 2 components, initiating the alarm.

This type uses 2 insulated wires within an outer covering. When the rated temperature is reached, the insulation melts and allows the 2 wires to touch.

FIRE ALARM SYSTEMS & COMPONENTS Rate of rise heat detectors Operates on principle that room temperature will rise faster from a fire than from atmospheric temperature change Usually designed to initiate an alarm when increase in temperature exceeds 12 degrees to 15 degrees F. per minute Being initiated by sudden rise in temperature, regardless of initial temperature, it can initiate an alarm at temperatures much lower than required by a fixed-temperature detector Automatically resets, if not damaged 4 Types: pneumatic rate-of-rise spot detector, pneumatic rate-of-rise line detector, rate-compensated detector, and thermoelectric detector

Rate-of-rise spot heat detector

Pneumatic rate-of-rise heat detector

Cutaway of a rate-compensated heat detector

Thermoelectric heat detector Operates when 2 wires of different Material are twisted together and Heated at one end, an electric current is generated at the other end. The rate at which the wire are heated determines the amount of current that is generated. These detectors are designed to “bleed off” or dissipate small amounts of current.

FIRE ALARM SYSTEMS & COMPONENTS Smoke detectors can initiate an alarm much more quickly due to smoke, not heat, being generated. Photoelectric Uses a photoelectric cell with a specific light source by either beam application or refractory applications More sensitive to smoldering fires Powered by battery, household current, or household current with battery backup

FIRE ALARM SYSTEMS & COMPONENTS Ionization Uses a small amount of radioactive material to ionize air molecules Products of combustion interrupt electrical charge within chamber, causing alarm More responsive to flaming fires Powered by battery, household current, or household current with battery backup

FIRE ALARM SYSTEMS & COMPONENTS Flame detectors Type that detects light in the ultraviolet wave spectrum Type that detects light in the infrared wave spectrum Those that detect both types of light UV Flame Detector: The UV sensor has been carefully selected to ensure the greatest degree of spectral matching to the radiant energy emissions of fire.

IR Flame Detectors From Detector Electronics Infrared detectors respond to flaming fires emitting light in the infrared portion of the spectrum. IR detectors can respond to a fire condition in less than 50 milliseconds. These detectors are designed to alarm to hydrocarbon fires, while ignoring things like arc welding, nuclear radiation and x-rays. IR detectors are available in single wavelength or dual wavelength. Both normal and high speed versions are available.

X5200 UVIR Flame Detector Advanced detection capabilities and immunity to extraneous sources.  The mounting arrangement allows the UV and IR sensors to monitor the same hazardous location with a 90 degree cone of vision.  When both sensors simultaneously detect the presence of a flame, an alarm signal is generated.  The detector has Division and Zone explosion-proof ratings and is suitable for use in indoor and outdoor applications. Automatic, manual or magnetic optical integrity testing

FIRE ALARM SYSTEMS & COMPONENTS Fire/Gas detectors Measure carbon dioxide and carbon monoxide produced by fire More discriminating than other detectors Designed to be sensitive to only gases produced by specific hostile fire activity and to ignore gases produced by constructive gases.

FIRE ALARM SYSTEMS & COMPONENTS Identify the value of automatic sprinklers in providing safety to the occupants of a structure 2-18.2 Discharges water directly on fire Operates while fire is small (incipient phase) Products of combustion are limited Effective in preventing fire spread to upper floors Provides a better chance of survival for occupants of upper floors

VALUE OF AUTOMATIC SPRINKLERS Discharges water directly on fire Operates while fire is small Products of combustion are limited Effective in preventing fire spread to upper floors Provides a better chance of survival for occupants of upper floors (By cooling the fire gases rising from the fire, the sprinkler prevents the fire from reaching the flashover stage.) Fire records show that 93 percent of of fires are handled by only one sprinkler. (In the remaining cases, two sprinklers handled an additional four percent. It took three sprinklers to handle nearly all of the remaining 3 percent.)

VALUE OF AUTOMATIC SPRINKLERS Sprinklers are the most effective fire safety device ever invented.  Look at this comparison with smoke alarms and with no fire protection at all. The National Fire Protection Association reports that people with smoke alarms in their home have a 50 percent better chance of surviving a fire. Adding sprinklers and smoke alarms increases your chances of surviving a fire by over 97 percent.

The threaded end screws into a water pipe in the ceiling and is not visible from below. The cap seals the opening and prevents water from flowing out. The glass bulb holds the cap/seal in place. The glass bulb is filled with liquid. Heat from a fire expands the liquid, which breaks the bulb. The cap/seal falls away and water will stream out. The water stream hits the deflector, which breaks it into a spray of tiny droplets.

FIRE DEPARTMENT SPRINKLER CONNECTION Water flow alarm Located outside the building usually close to the sprinkler connection Indicates that water is flowing through the system Operated either hydraulically or electrically

FIRE DEPARTMENT SPRINKLER CONNECTION Fire department connection Located outside the building Is usually a siamese connection with two 2 ½ inch female connections with a clapper valve or one clappered large-diameter inlet Used to connect supply lines to the sprinkler system

Fire Department Connection [FDC]

Fire Department Connection [FDC]

MAIN CONTROL VALVE Used to cut off the water supply Located between source and sprinkler system Most often located under alarm valve or outside near the system controls

MAIN CONTROL VALVE Outside screw and yoke (OS & Y) Post indicator Open when the word “OPEN” is visible in window Post indicator Open when the word “OPEN” is in the window Wall post indicator Post indicator valve assembly Has a sight area that is open then the valve is open or may have an indicating paddle Valve is a butterfly valve

Small OS&Y Valve

Know The Difference Post Indicating Valve Post Indicating Valve (PIV) Assembly (PIVA) Post Indicating Valve (PIV)

Wall Post Indicating Valve (WPIV)

AUTOMATIC SPRINKLER HEAD Fusible link Fusible link, holding two levers together, is melted during fire Levers and caps are pushed out of the way by water Water stream strikes the deflector and is converted into a spray

AUTOMATIC SPRINKLER HEAD Glass bulb Small bulb is filled with liquid and air bubble is heated by fire until bulb shatters The cap is pushed out of the way by water Water stream strikes the deflector and is converted into a spray

AUTOMATIC SPRINKLER HEAD Chemical pellet Pellet of solder under compression melts during fire Plunger moves down releasing valve cap parts Water stream strikes the deflector and is converted into a spray

AUTOMATIC SPRINKLER HEAD Quick release Specially designed fusible link with greater surface area absorbs heat faster and responds quicker

AUTOMATIC SPRINKLER HEAD Sprinkler Position: Pendant Upright Sidewall Special-purpose

Pendant

Upright

Sidewall

Special Purpose Used in specific applications because of their unique characteristics. Several Types for special areas & uses. Corrosive Coatings Recessed into Ceilings

Sprinkler Storage Storage Cabinet for housing extra sprinklers and a sprinkler wrench should be installed by the sprinkler system. Normally, these cabinets hold a minimum of 6 sprinklers and a sprinkler wrench in accordance with NFPA 13 & 13D. The function of changing sprinklers is performed by representatives of the building who are qualified to perform the work on sprinkler systems.

HOOD AND DUCT SYSTEM Used for local application, meaning only portion of building, directly where the hazard exists Restaurant cooking areas Laboratory hood systems Paint booths Other hazardous areas

HOOD AND DUCT SYSTEM Uses a heat sensitive device (such as a fusible link) or manually activated switch for activation Extinguishing agents may be: Fine water spray Dry chemical Wet chemical Carbon Dioxide (CO2) Halogenated or clean agents

WET & DRY PIPE SYSTEMS Wet pipe system Used in location where piping will not be subjected to temperatures below 40 degrees F. (4 degrees C) Maintains water under pressure at all times Connected to the public water supply so fused sprinkler can discharge a water spray in area while sounding alarm Both sides of control valve have pressure gauges to indicate water pressure of the supply and of the system System side pressure should read slightly higher than supply side pressure

WET & DRY PIPE SYSTEMS Dry pipe system Used in location where piping is subjected to temperatures below 40 degrees F (4 degrees C) All pipes are pitched to drain system back to main drain Air under pressure replaces water in piping above the dry-pipe valve When sprinkler fuses, pressurized air escapes first, and dry-pipe valve opens to allow water into piping system

WET & DRY PIPE SYSTEMS Quick opening devices are installed in systems with water capacity over 500 gallons to accelerate the opening of the dry-pipe valve. The dry pipe valve is equipped with an air pressure gauge above the clapper and a water pressure gauge below the clapper The air pressure gauge will read substantially lower than the water pressure gauge If the gauges read the same, this is an indication the system has been tripped and water has entered the pipes

CONNECTING HOSELINES Locate fire department connection Select proper type and amount of hose Advances hose to fire department connection Removes cover from fire department connections Checks fire department connection for damage or obstructions Connects hose to fire department connection

CONNECTING HOSELINES Connects hose to proper discharge outlets on pumper Notifies officer or pumper engineer that connection has been completed

STOPPING THE FLOW OF WATER Wooden wedges Positions ladder close to sprinkler head With someone supporting ladder, climbs to a height that the sprinkler head can be reached Insert one or more wedges Tap until flow of water stops or diminishes to a trickle

STOPPING THE FLOW OF WATER Commercial stopper Positions ladder close to sprinkler head With someone supporting ladder, climbs to a height that the sprinkler head can be reached Inserts the stopper between the orifice and the deflector If the operation of some type of device is necessary to open the stopper, operates it at this time until the flow stops or diminishes to a trickle

OPERATING A MAIN CONTROL VALVE Outside screw and yoke (OS & Y) valve Unlock any means to secure the valve in the open position and remove it Grasp the wheel and slowly turn it until the yoke completely disappears When instructed to do so, turn the wheel slowly until the yoke is extended as far as possible Secure the valve in the “OPEN” position

OPERATING A MAIN CONTROL VALVE Post Indicator Valve (PIV) Unlock any means used to secure the valve in the open position and remove it Remove the handle and place it on the operating nut Slowly rotate the operating nut until the word “CLOSED” can be seen in the window When instructed to do so, rotate the operating nut slowly until the word “OPEN” can be seen in the window Secure the valve in the open position

OPENING & CLOSING THE MAIN DRAIN VALVE If main valve is an OS & Y valve: To open: Turn handle slowly until stem is fully extended To close: Turn handle until stem is no longer visible Other types of valves (globe, butterfly, etc): Turn handle slowly to fully “OPEN” position Turn handle slowly to fully “CLOSED” position

READING & RECORDING INDICATED PRESSURES Note: Perform this evolution according to the type of system being used in the exercise. Read and record water pressure on supply side Read and record water pressure on system side

Homework 4. 1. 5. 2. 3. Deflector b. frame arms c. lever arms d. Release Mechanism (Fusible Link) e. valve cap 1. 5. 2. 3.

Homework 6. 7. 8. 9. Chemical Pellet Frangible Bulb Fusible Link (Quick Response) Fusible Link (Standard) 8. 9.

VS 15-3 Homework 12. 10. 11. a. Pendant b. Sidewall c. Upright

Homework 16. 13. 14. 15. 17. Main Control Valve (OS&Y) b. OS&Y (Outside Screw and Yoke) c PIV (Post Indicator Valve) d. PIVA (Post Indicator Valve Assembly) e. WPIV (Wall Post Indicator Valve)

Homework Select facts about a sprinkler system’s fire department connection. Write the correct letters on the blanks. 18. Which of the following best describes the basis for establishing a minimum flow rate? a. Hazard being protected and its volatility b. Number of occupants in the building c. Available water supply and private pipe diameters d. Hazard being protected, occupancy, and building contents 19. At what residual pressure must a minimum water supply be able to deliver the required volume of water to the highest sprinkler in a building? a. 15 psi b. 30 psi c. 20 psi d. 25 psi 20. When does a sprinkler system need an outside source of water and pressure? a. In a chemical fire b. During a large fire or when a pipe breaks c. When some of the system pipes are frozen due to extreme cold d. During an electrical fire 21. What type of valve prevents water from flowing from a sprinkler system back into a fire department connection? a. Check b. Globe c. Main d. Stop 22. Firefighter A says that a fire department connection to a sprinkler system may consist of a siamese with at least two 2½-inch (65 mm) female connections with a clapper valve. Firefighter B says that a fire department connection to a sprinkler system may be a large-diameter connection with a clappered inlet. Who is right? a. Firefighter A b. Firefighter B c. Both A and B d. Neither A nor B

Homework 23. Why would a ball drip valve be installed at a fire department connection? a. To ease back pressure against the check valve b. To keep the connection and check valve dry and functional during freezing conditions c. To release excess water from the system d. For relief of pressure against the main valve 24. What is the minimum recommended pump capacity for a pumper supplying a sprinkler system? a. 1,500 gpm b. 2,000 gpm (8 000 L/min) c. 2,500 gpm d. 1,000 gpm 25. Firefighter A says that the water supply for a sprinkler system is designed to supply all of the sprinklers actually installed on the system. Firefighter B says that fire department pumpers supporting sprinkler systems should operate from the main that is supplying the sprinkler system. Who is right? a. Firefighter A b. Firefighter B c. Both A and B d. Neither A nor B 26. How can firefighters determine the proper direction of water flow through a check valve? a. By arrows on the valve or the appearance of the valve casting b. By the name of the manufacturer c. By the check valve flow designation stamped on the valve casting d. By the stamped metal instruction tag chained to the valve casting

Homework Select facts about guidelines for operations at sprinkler-protected properties. Write the correct letters on the blanks. 27. Which of the following is not a recommended method of insuring adequate water supply to a sprinkler system? a. Limit the use of direct hoselines from the water supply system serving the sprinkler system. b. Establish a second water supply for hoselines if necessary. c. Increase sprinkler discharge by increasing the pressure on the system. d. Shut off water supply to individual sprinkler heads as soon as firefighters begin their attack. 28. What action should be taken when a sprinkler control valve is closed? a. A firefighter with a portable radio should be stationed at the valve. b. All pumpers should be disconnected from the fire department connection. c. Firefighters should service damaged sprinklers and system components. d. The control valve should be secured shut and tagged. 29. Which of the following is a proper method for stopping the flow of water from a single sprinkler? a. Shut off the water supply for that section of the system. b. Shut off the water supply for the whole system. c. Insert a wood wedge between the deflector and the discharge orifice. d. Reinsert the sprinkler release plug into sprinkler orifice.

Homework 30. When should sprinkler control valves be closed? a. Before firefighters begin their attack b. Not until the fire is completely extinguished c. Not until fire officers are convinced that further operations will simply waste water, produce heavy water damage, or hamper final extinguishment d. When firefighters leave the premises 31. When should pumpers be disconnected from the system? a. As soon as fire officers determine the system is operating at full volume b. Not until extinguishment has been determined by thorough overhaul c. As soon as the fire is under control d. Not until fire officers are convinced that further operations will simply waste water, produce heavy water damage, or hamper final extinguishment

Homework Match types of alarm-initiating devices to their descriptions. Write the correct letters on the blanks. 32. __ Is activated when heat causes solder to melt so that an electrical circuit is closed 33. __ Is activated when heat causes a bubble in a glass vial to expand until the bulb fractures so that an electrical circuit is closed 34. __ Consists of a length of cable that reacts to heat by changing electrical resistance or by making electrical contact when wire insulation melts 35. __ Uses a component made of two different types of metal that expand at different rates 36. __ Uses the expansion of heated air in a chamber to force a metal diaphragm against contact points 37. __ Uses the expansion of heated air in tubing to create an electrical connection ANSWER BANK a. Bimetallic Detector b. Continuous Line Detector Tubing Type c. Fusible Detector d. Pneumatic Spot Detector e. Thermoelectric

Homework 38. Uses two bowed struts inside a metallic sleeve so that it can be activated either by the expansion of the struts or the expansion of the sleeve 39. Is activated when two twisted wires of dissimilar metals are heated, producing an electrical current 40. Uses a light source and a receiver and is activated when smoke breaks the light beam 41. Uses an internal lamp, the light of which is diffused by smoke so that it contacts a photocell 42. Uses a radioactive material to ionize air molecules within a chamber to allow electrical flow until smoke makes the air less conductive a. Continuous Line Detector Wire Type b. Ionization- Chamber Smoke Chamber c. Photoelectric Smoke Detector Beam Type d. Photoelectric Smoke Detector Refractory e. Pneumatic Line

Homework Select facts about heat detectors. Write the correct letters on the blanks. 43. The normal location for a fixed-temperature heat detector is ___. a. Over the facility doors c. High in the room b. Near the baseboards of the walls d. At a mid-height level in the room 44. Which of the following is not one of the principles of physics used to detect heat in fixed-temperature devices? A. Expansion of heated material b. Melting of heated material c. Changes in electrical resistance of heated material d. Contraction of heated material 45. Firefighter A says that fixed-temperature heat detectors are the type of detectors least likely to produce false activations. Firefighter B says that a fixed-temperature heat detector is the slowest detector to activate. Who is right? a. Firefighter A b. Firefighter B c. Both A and B d. Neither A nor B 46. A detector that monitors a single area is referred to as a ___ detector? a. Fusible b. Frangible c. Continuous line d. Spot

Homework 47. Which of the following is not true of rate-of-rise heat detectors? a. They should be placed near exterior doorways. b. They typically respond to rates of rise that exceed 12 to 15 degrees Fahrenheit per minute. c. They are reliable and are not subject to false activations. d. They automatically reset if undamaged by the fire. 48. What is the recommended maximum length of tubing in pneumatic rate-of-rise line detector systems? a. 1,000 feet b. 100 feet c. 30 feet d. 15 feet 49. Which of the following statements is true? The purpose of rate compensation in heat detectors is to eliminate the need for having a fixed a. temperature at which the alarm will activate. b. The wires of a thermoelectric detector must be made of the same kind of metal in order for the system to produce electric current. c. Fixed-temperature heat detectors should have an activation temperature slightly above the highest expected temperature for the room. d. Because of their high reliability, the use of frangible-bulb detectors continues to grow in popularity for light industrial applications.

Homework Select facts about smoke detectors. Write the correct letters on the blanks. 50. Alarms that use light to detect products of combustion are referred to as ___. a. Photoelectric smoke detectors c. Ionization smoke detectors b. Rate-compensated detectors d. Flame detectors 51. Photoelectric detectors are generally more sensitive to ___ than are ionization detectors. A. Smoldering fires b. Flaming fires c. Fire gases d. Invisible products of combustion 52. Which of the following statements is true? a. Ionization smoke detectors are not recommended for residential properties because of the radioactive material they contain. b. After activation, ionization smoke detectors must be taken to a service center to have the collector electrodes restored. c. Smoke detectors respond quickly. d. Most smoke detectors also contain sensors for detecting high levels of carbon monoxide. 53. Smoke detectors are normally powered by ___. A. Photocells b. Ionization chambers C. Bimetallic solar cells d . Household current or batteries

Homework 54. The most common reason for failure of a smoke detectors is ___. a. Excessive heat prior to the generation of enough smoke to activate the alarm b. Power failures in household circuits c. Poor maintenance of batteries d. Failure to change the radioactive material twice per year 55. Firefighter A says that beam-application smoke detectors are not self-resetting. Firefighter B says that photoelectric smoke detectors are not self-resetting. Who is right? a. Firefighter A b. Firefighter B c. Both A and B d. neither A nor B

Homework Complete statements about flame detectors. Select the correct word for the blanks. 56. __ (a. Ultraviolet, b. Infrared) flame detectors may be sensitive to sunlight. 57. __ Flame detectors must have an (a. unobstructed, b. overhead) view of the fire site. 58. __ (a. Ultraviolet, b. Infrared) flame detectors may be sensitive to welding equipment or mercury-vapor lamps. 59. __ Most IR detectors are designed to require (a. steady, b. flickering) light.

Homework Complete statements about fire-gas detectors. Select the correct words for the blanks. 60. __ Fire-gas detectors are the (a. most, b. least) common type of fire detector. 61. __ All fires release water vapor, carbon dioxide, and (a. oxygen, b. carbon monoxide). 62. __ Fire-gas detectors will initiate an alarm (a. faster, b. slower) than a heat detector. 63. __ Fire-gas detectors can be (a. more, b. less) discriminating than other types of detectors.

Homework Match types of automatic alarm systems to their descriptions. Write the correct letters on the blanks. 64. An auxiliary alarm system within an occupancy that is attached directly to a hard-wired or radio-type municipal fire alarm box 65. An auxiliary alarm system in which the municipal alarm circuit extends into the protected property 66. An auxiliary alarm system that transmits alarms from the protected property to the alarm center over a municipally controlled telephone circuit a. Local energy system b. Parallel telephone system c. Shunt system

Homework 67. A system that connects to the telecommunications center or answering service through a means other than the municipal fire-alarm-box system 68. A system that provides coverage to a large building or complex of commonly owned buildings connected to a monitoring station 69. A system that provides coverage to several sites connected to an off-site contracted service a. Central station system b. Proprietary system c. Remote station system

Homework Select facts about supervising fire alarm systems. Write the correct letters on the blanks. 70. Fire alarm systems are designed to be ___. A. Self-supervising b. Maintained with no more than weekly inspection c. Maintained with no more than daily inspection d. Inspected through the use of an operator-initiated signal issued each hour 71. Self-diagnosing systems with built-in microprocessors provide test results on ___. a. Request of the system supervisor b. Punched tape c. A printer or computer screen d. Microchips 72. Firefighter A says that control panels for manual pull stations must be listed by a testing laboratory for this purpose. Firefighter B says that control circuits for suppression systems that use manual pull stations or automatic detection devices do not need to be supervised. Who is right? a. Firefighter A b. Firefighter B c. Both A and B d. Neither A nor B 73. By regulation, carbon dioxide systems are required to have a ___. a. Motion sensor to detect the presence of people b. Smoke detector system c. Back-up sprinkler system d. Predischarge alarm 74. Water flow alarms are normally set to respond to flow equal to that of ___. A. One sprinkler b. Two sprinklers c. One-tenth of the system d. One-half of the system

Homework Complete statements about water flow alarms. Select the correct word for the blanks. 75. (a. Hydraulic, b. Electric) water flow alarms are local systems that alert personnel in the building and passersby. 76. Water flow alarms are actuated by the flow of (a. electricity, b. hydraulic fluid, c. water). 77. (a. Hydraulic, b. Electric) water flow alarms use water in the system to branch off to a water motor to drive a local alarm gong. 78. (a. Hydraulic, b. Electric) water flow alarms can be connected to systems to notify the fire department.

Homework Match sprinkler system applications to their descriptions. Mark the correct letters on the blanks. 79. Used in locations that will not be subjected to temperatures below 40°F (4°C) 80. Used in locations that may be subjected to temperatures below 40°F (4°C) 81. Used when it is important to prevent water damage even if the pipes are broken 82. Used to wet down an area through the use of open sprinkler heads 83. Used in one- and two-family dwellings a. Deluge b. Dry-pipe c. Preaction d. Residential e. Wet-pipe