0. Fire Detection and Suppression
Chapter 2
Fire Detection and Signaling Systems

1. Fire Detection and Signaling Systems
The early detection of a fire and the signaling of an appropriate alarm remain the most significant factors in preventing large losses from occurring.
Fire Detection and Signaling Systems

2. Fire Detection and Signaling Systems
Standards and Codes
Component tests by nationally recognized labs
Underwriters Laboratories
Factory Mutual
Codes
NFPA 70, National Electrical Code
NPFA 72, The National Fire Alarm Code
Local codes and ordinances
Fire Detection and Signaling Systems

3. Basic System Components
System control unit (alarm panel)
Brain of system
Processes alarm signals from actuating devices and transmits them to the local or other alerting system
Fire Detection and Signaling Systems

4. Basic System Components (cont.)
Power supply
Primary power supply
Public electric utility
Engine-driven generator
Secondary power supply
Storage battery and charger
Engine-driven generator and 4-hour storage battery
Multiple engine-driven generators
Trouble signal power supply
Fire Detection and Signaling Systems

5. Basic System Components (cont.)
Initiating devices: manual pull stations, heat detectors, smoke detectors, flame detectors, waterflow devices, tamper switches, and combination detectors
Notification appliances: bells, buzzers, horns, recorded voice messages, strobe lights, speakers, and other warning appliances
Auxiliary services
Fire Detection and Signaling Systems

6. Types of Fire Alarm Systems
Selection factors
Level of life-safety hazard
Structural features of the building
Level of hazard presented by the contents of the building
Availability of fire suppression resources
State and local code requirements
(Continued)
Fire Detection and Signaling Systems

7. Types of Fire Alarm Systems (cont.)
Local system
Noncoded local alarm
Simultaneous operation of all alarm-indicating devices
Only practical in small occupancies with limited number of rooms
Master coded local alarm
Serves the premises as a local control unit and receives input from other fire alarm control units
Used in occupancies that use the alarm signals for other purposes
(Continued)
Fire Detection and Signaling Systems

8. Types of Fire Alarm Systems
Local system (cont.)
Zoned/annunciated alarm
Identifies fire location quickly and accurately
Alarm-initiating devices arranged in circuits or zones
Initiating device sounds alarm and lights corresponding lamp on control unit
Annunciator panel remote from control panel
Coded signals
Presignal alarm
(Continued)
Fire Detection and Signaling Systems

9. Types of Fire Alarm Systems (cont.)
Auxiliary system
Facility that receives signals where personnel are always present to respond
Initiation devices
Local requirements and policies
Types of auxiliary systems
Local energy system
Shunt system
Parallel telephone system
(Continued)
Fire Detection and Signaling Systems

10. Types of Fire Alarm Systems (cont.)
Remote station system
Connected to dispatch center by means other than municipal fire alarm box system
Local alarm capability
Monitoring options
(Continued)
Fire Detection and Signaling Systems

11. Types of Fire Alarm Systems (cont.)
Proprietary system
Used to protect large buildings or facilities
Systems for individual buildings or areas wired into common receiving point
Wide-ranging capabilities
(Continued)
Fire Detection and Signaling Systems

12. Types of Fire Alarm Systems (cont.)
Central station system
Similar to proprietary system but receiving point is an outside, contracted central station
Alarm activation information received by central station employees, who initiate emergency response
(Continued)
Fire Detection and Signaling Systems

13. Types of Fire Alarm Systems (cont.)
Emergency voice/alarm communications system
Supplements other systems
Communicates detailed information to occupants and fire fighting personnel
One-way/two-way
Fire Detection and Signaling Systems

14. Manual Alarm-Initiating Devices
General requirements
Mounting and distribution
Generally not required in fully sprinklered structures
Outmoded “broken glass” pull stations
Coded versus noncoded pull stations
Single-action and double-action pull stations
Fire Detection and Signaling Systems

15. Automatic Alarm-Initiating Devices
Continuously monitor atmosphere
Four basic types
Heat detectors
Smoke detectors
Fire-gas detectors
Flame detectors
Fire Detection and Signaling Systems

16. Fire Detection and Signaling Systems
Heat Detectors
Fixed temperature heat detectors
Fusible links/frangible bulbs
Continuous line detector
Bimetallic detector
Rate-of-rise heat detector
Pneumatic rate-of-rise spot detector (Fig. 2.34)
Pneumatic rate-of-rise line detector (Fig. 2.35)
Rate compensated detector (Fig. 2.36)
Thermoelectric detector
Fire Detection and Signaling Systems

17. Fire Detection and Signaling Systems
Smoke Detectors
Photoelectric smoke detector
Projected beam (Fig. 2.37)
Refractory photocell (Fig. 2.38)
Ionization smoke detector (Fig. 2.39)
Dual chamber
Air-sampling smoke detectors
Cloud chamber (Fig. 2.40)
Second type (Fig. 2.41)
(Continued)
Fire Detection and Signaling Systems

18. Smoke Detectors (cont.)
Limitations
May not provide early warning of a fire developing on another level of a building
May not detect fire developing on the other side of a closed door
May not be effective when fire is caused by explosions resulting from careless housekeeping
Fire Detection and Signaling Systems

19. Fire Detection and Signaling Systems
Flame Detectors
Types
Ultraviolet (UV) Fig. (2.42a)
Infrared (IR) Fig. (2.42b)
Fast to respond
Frequent false alarms
Fire Detection and Signaling Systems

20. Fire Detection and Signaling Systems
Fire Gas Detectors
Monitors levels of gases released by combustion
Carbon dioxide
Carbon monoxide
Faster than heat detectors but slower than smoke detectors
Fire Detection and Signaling Systems

21. Combination Detectors
Various possible combinations
Fixed rate/rate-of-rise detectors
Heat/smoke detectors
Smoke/fire gas detectors
Offer benefits of both systems and increase responsiveness to fire conditions
Fire Detection and Signaling Systems

22. Fire Detection and Signaling Systems
Acceptance Testing
Should be observe by representatives of building owner, fire department, system installer, and system manufacturer.
All functions of the fire detection and signaling system should be operated:
All alarm-indicating and alarm-initiating devices
Restorable heat detectors
Response of outside entities responsible for monitoring the system
Fire Detection and Signaling Systems

23. Fire Detection and Signaling Systems
General Inspections
Fire department participation
Checkpoints
Condition of wiring and batteries
All equipment free of foreign materials
Adequate clearance around system control units, recording instruments, and other devices
Fire Detection and Signaling Systems

24. Inspecting and Service Testing Initiating Devices (cont.)
Manual alarm-initiating devices
Automatic alarm-initiating devices
Detectors must not be damaged or painted.
Replace or send the following detectors to a recognized testing laboratory for testing:
Detectors on systems that are being restored to service after a period of disuse
Detectors that are obviously corroded
(Continued)
Fire Detection and Signaling Systems

25. Inspecting and Service Testing Initiating Devices (cont.)
Automatic alarm-initiating devices
Replace or send the following detectors to a recognized testing laboratory for testing (cont.):
Detectors that have been painted over, even if attempts were made to clean them
Detectors that have been mechanically damaged or abused
Detectors on circuits that were subjected to current surges, overvoltages, or lightning strikes
(Continued)
Fire Detection and Signaling Systems

26. Inspecting and Service Testing Initiating Devices (cont.)
Automatic alarm-initiating devices
Replace or send the following detectors to a recognized testing laboratory for testing (cont.):
Detectors subjected to foreign substances that might affect their operation
Detectors subjected to either direct flame, excessive heat, or smoke damage
Testing
Nonrestorable
Restorable
Fire Detection and Signaling Systems

27. Inspecting System Control Units
Control panel switches and functions
Auxiliary devices
Receiving signals
Fire Detection and Signaling Systems

28. System Testing Timetables
Local systems: local guidelines
Central station systems: monthly
Auxiliary systems: monthly (noncoded fire alarm boxes: monthly)
Remote station and proprietary systems: authority having jurisdiction
Emergency voice/alarm systems: quarterly
NOTE: In all cases, check the most current edition of NFPA 72, National Fire Alarm Code.
Fire Detection and Signaling Systems

29. Fire Detection and Signaling Systems
Record Keeping
Maintaining Files and Records
Documents:
Inspection reports, forms, and letters
Violation notices
Summonses
Plans review comments, approvals, and drawings
Fire reports
Investigations
Permits and certificates issued
(Continued)
Fire Detection and Signaling Systems

30. Fire Detection and Signaling Systems
Record Keeping
Maintaining Files and Records (cont.)
Occupancies:
Those that have been issued a permit, certificate, or license
Those that contain automatic fire suppression or detection systems
Those that conduct hazardous operations or routinely house hazardous materials
Duration: life of structure
Public record
(Continued)
Fire Detection and Signaling Systems

31. Fire Detection and Signaling Systems
Record Keeping (cont.)
Written records
File for each inspected property
Cataloging and storage
Electronic records
Two primary methods of entering data:
Inspectors use laptop computers or handheld electronic data recording equipment during the inspection.
Inspectors use written forms during the inspection and then enter the information upon returning to the office.
(Continued)
Fire Detection and Signaling Systems

32. Fire Detection and Signaling Systems
Record Keeping (cont.)
Electronic records (cont.)
Considerations in computer system management
How will the information be filed?
How can the information be retrieved?
What portion of the information will be stored in a read-only format?
What personnel will be given access to retrieve information from the system?
What information can be released to the public?
Fire Detection and Signaling Systems