FIRE DETECTION & ALARM SYSTEMS.pdf
- 1. Presentation on Fire Detection & Alarm Systems AR. AFAQ AHMED AR. SHADAB SAIFI
- 2. Fire Detection and Alarm System is electronic equipment which detects fire and raises alarm as warning of fire. A fire alarm system is number of devices working together to detect and warn people through visual and audio appliances when smoke, fire, carbon monoxide or other emergencies are present. INTRODUCTION FIRE PROTECTION ACTIVE FIRE DETECTION LIFESAFETY PASSIVE LIFE SAFETY is an integral part of the building layout and materials of construction come into play only when a fire is present and require activation through a combination of sensors or mechanical means. FIRE DETECTION AND ALARM SYSTEMS
- 3. Heat Light Underlying principle for detection Smoke Three things produced by fire forms the basis of detection It protects by: •Detecting a fire at an early stage •To alert occupants, so that they escape the building safely. •Notifying the relevant personnel •To initiate automatic fire control and suppression system. •Identifying and guiding fire fighters FIRE DETECTION AND ALARM SYSTEMS
- 4. VARIOUS STANDARDS FOR FIRE DETECTION AND ALARM SYSTEMS NBC:2016 : Fire and life safety – Part 4 IS:2189 : Indian Standard for Selection, installation and Maintenance of Automatic Fire Detection And Alarm System – Code of Practice NFPA :72 : National Fire Alarm Code, USA BS: 5839-1 : Fire detection and alarm systems for buildings —Part 1 FIRE DETECTION AND ALARM SYSTEMS
- 5. FIRE DETECTION AND ALARM SYSTEMS 1. CONTROL PANEL 2. INITIATION DEVICE 3. ALARM NOTIFICATION DEVICE FIRE ALARM SYSTEM COMPONENTS CASE 1 CASE 2 INITIATION DEVICE CONTROL PANEL NOTIFICATION DEVICE
- 6. a. Control panel serves as the “brain” of the system. b. Manages and monitors the proper operation of the system c. It can indicate the source of an alarm so that responding fire personnel will know what activated the alarm and where the initial activation occurred. d. Also manages the primary power supply and provides a backup power supply for the system. e. It may perform additional functions, such as notifying the fire department when the alarm system is activated, and may interface with other systems and facilities. f. Control panels vary greatly, depending on the age of the system and the manufacturer. g. Fire alarm control panels are used to silence the alarm and reset the system. h. Many buildings have an additional display panel, called a remote annunciator, in a separate location. i. The fire alarm control panel should also monitor the condition of the entire alarm system to detect any faults. j. A fire alarm system is usually powered by a 110-volt line, even though the system’s appliances may use a lower voltage. k. In some systems, a battery in the fire alarm control panel will automatically activate when the external power is interrupted. l. The control panel in a large building may be programmed to perform several additional functions. 1. CONTROL PANEL FIRE DETECTION AND ALARM SYSTEMS
- 7. FIRE ALARM CONTROL UNITS (NFPA 3.3.99) •The fire alarm control unit (FACU), formerly called the fire alarm control panel (FACP), contains the electronics that supervise and monitor the integrity of the wiring and components of the fire alarm system. •The FACU --- the brain for the alarm system. • It receives signals from alarm-initiating devices--- processes the signals,& produces output signals that activate audible and visual appliances. •The FACU also transmits signals to an off-site monitoring station . •Power and fire alarm circuits are connected directly into this panel. FACU can also perform other functions, such as: •Providing two-way firefighter communication •Controlling elevators, HVAC, fire doors, dampers, locks, or other fire pro- tection features •The FACU can also provide public address messages and mass notifications alerts through prerecorded evacuation messages or independent voice communications. This schematic shows the different components of a re alarm control unit (FACU), the central hub of an alarm system. FIRE DETECTION AND ALARM SYSTEMS
- 8. PRIMARY POWER SUPPLY On the power supply circuit board, one switch should be permanently labeled as the FACU (sticker in the photo) to ensure that anyone doing maintenance on the circuit board does not deactivate that switch and create a safety hazard. The primary electrical power supply usually comes from the building’s main power connection to the local utility provider The FACU must supervise the primary power supply and signal an alarm if the power supply is interrupted SECONDARY POWER SUPPLY All fire alarm systems must have a secondary power supply. This requirement is designed so that the system will be operational even if the main power supply fails. Secondary power sources can consist of batteries with chargers, engine-driven generators with a storage battery, or multiple engine-driven generators, of which one must be set for automatic starting A backup battery, like the one under the circuit board in the photo, should be available to all components of a re detection system if primary power is unavailable. An FACU can monitor alarms, control elevators, and public address messages. The system shall be capable of powering the required load for a duration of not less than 24 hours, as required in NFPA 72. FIRE DETECTION AND ALARM SYSTEMS
- 9. 2. INITIATING DEVICES A ceiling-mounted re alarm speaker and strobe light combination unit. A fire detection system consists of manual and automatic alarm-initiating devices that are activated by the presence of fire, smoke, flame, or heat. Smoke detectors Flame detectors Heat detectors Different types of smoke detectors. Smoke and carbon mono-oxide combination detector MANUAL ALARM-INITIATING DEVICES Manual pull stations AUTOMATIC ALARM-INITIATING DEVICES FIRE DETECTION AND ALARM SYSTEMS
- 10. NOTIFICATION APPLIANCES (NFPA 3.3.102) Audible notification signaling appliances are the most common types of alarm-signaling systems used for signaling a fire alarm in a structure. Once an alarm-initiating device is activated, it sends a signal to the FACU, which then processes the signal and initiates actions. The primary action initiated is usually local notification, which can take the form of: • Bells • Buzzers • Horns • Speakers • Strobe lights • Other warning appliances Notification appliances fall under the following categories : • Audible — Approved sounding devices, such as horns, bells, or speakers, that indicate a fire or emergency condition. • Visual — Approved lighting devices, such as strobes or flashing lights, that indicate a fire or emergency condition. • Textual — Visual text or symbols indicating a fire or emergency condition. • Tactile — Indication of a fire or emergency condition through sense of touch or vibration. Noti fication devices include bells, horns, strobe lights, and speakers FIRE DETECTION AND ALARM SYSTEMS
- 11. ADDITIONAL ALARM SYSTEM FUNCTIONS (NFPA 3.3.278.1) Magnetic door closures like this one are designed to remain open during normal building activity and release when alarms are activated Building codes have special requirements for some types of occupancies in case of fire. In these cases, the fire detection and alarm system can be designed to initiate the following actions: • Turn off the heating, ventilating, and air-conditioning (HVAC) system • Close smoke dampers and/or fire doors . • Pressurize stairwells and/or operate smoke control systems for evacuation purposes • Unlock doors along the path of egress • Provide elevator recall to the designated floor and prevent normal operations . • Operate heat and smoke vents • Activate special fire suppression systems, such as preaction and deluge sprinkler systems or a variety of special-agent fire extinguishing systems Override of elevators controls to be only controlled by firefighters. FIRE DETECTION AND ALARM SYSTEMS
- 12. ALARM SIGNALLING SYSTEMS Several types of systems include the following: •Protected premises (local) •Supervising station alarm systems •Public emergency alarm reporting system •Emergency communications systems A local alarm system alerts occupants of one building to an incident occurring on that property. PROTECTED PREMISES SYSTEMS (LOCAL) A protected premises system is designed to provide notification to building occupants only on the immediate premises . The protected premises system can be activated by manual means, such as a pull station, or by automatic devices, such as smoke detectors. A protected premises system may also be capable of annunciating a supervisory or trouble condition to ensure that service interruptions do not go unnoticed. FIRE DETECTION AND ALARM SYSTEMS
- 13. 1. CONVENTIONAL ALARM SYSTEMS A conventional alarm system is the simplest type of protected premises alarm system. When an alarm-initiating device, such as a smoke detector, sends a signal to the FACU, all of the alarm-signaling devices operate simultaneously. FIRE DETECTION AND ALARM SYSTEMS
- 14. FIRE DETECTION AND ALARM SYSTEMS 2. ADDRESSABLE ALARM SYSTEMS Addressable alarm systems display the location of each initiating device on the FACU and an annunciator panel if provided . This connection enables emergency responders to pinpoint the specific device that has been activated.
- 15. 3. ZONED CONVENTIONAL ALARM SYSTEMS (NFPA 3.3.102) Fire-alarm system annunciation enables emergency responders to identify the general location, or zone, of alarm device activation. In this type of system, an annunciator panel, FACU, or a printout visibly indicates the building, floor, fire zone, or other area that coincides with the location of an operating alarm-initiating device Zoned systems are designed to help emergency responders quickly identify the location of a fire FIRE DETECTION AND ALARM SYSTEMS
- 16. 1. CENTRAL STATION SYSTEM A central station system is a listed supervising station that monitors the status of protected premises alarm systems and provides inspection, testing, and maintenance through contracted services . Multiple properties can be monitored in a central station system. Wire pairs to other buildings I n p u t s Outputs Telephone Exchange Central Office Area Central Station Alarm Console Direct Connection to Fire Department Protected Property No. 3 Protected Property No. 2 Protected Property No. 1 Central Station System Components 2. PROPRIETARY SYSTEM A proprietary system is used to protect large commercial and industrial buildings, high-rise structures, and groups of commonly owned facilities, such as a college campus or industrial complex in single or multiple locations. Modern proprietary systems can be complex and have a wide range of capabilities, including: •Coded-alarm and trouble signal indications •Remote Receiving System •The municipal fire department’s alarm communications center sending an alarm signal to the FACU. •Building utility controls Elevator controls •Fire and smoke damper controls A proprietary alarm system is used to monitor several commonly owned facilities, such as a number of university buildings, with one receiving point. SUPERVISING STATION ALARM SYSTEMS Fire alarm systems are required by model fire codes to be monitored at a constantly attended location. For buildings that are not constantly attended by qualified personnel. FIRE DETECTION AND ALARM SYSTEMS
- 17. EMERGENCY COMMUNICATIONS SYSTEMS An emergency communications system is a supplementary system that may be provided in facilities in conjunction with detection and alarm signaling systems. The purpose of emergency communications systems is to provide a reliable communication system for occupants and firefighters. One-way voice communication systems are commonly used to provide occupants in a structure with instructions during an emergency 1. Voice Notification Systems A one-way voice notification system warns building occupants that action is needed and tells them what action to take. This type is most commonly used in high-rise buildings, places of assembly, and educational occupancies 2. Two-Way Communication Systems This system is most helpful to fire suppression personnel who are operating in a building, particularly in high-rise structures that interfere with portable radio transmissions. 3. Mass Notification System (MNS) — System that notifies occupants of a dangerous situation and provides information and instructions. The purpose of a mass notification system (MNS) is to provide emergency communications to a large number of people on a wide-scale basis . This communication can be directed to the occupants of a building or even an entire community. FIRE DETECTION AND ALARM SYSTEMS
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- 19. FIRE DETECTION AND ALARM SYSTEMS A smoke detector is a device that detects smoke, typically as an indicator of fire. Smoke detector consists of two parts: 1. A sensor to sense the smoke. 2. An electronic horn to horn the people SMOKE DETECTOR (NFPA 3.3.65) 1. IONIZATION SMOKE DETECTORS An ionization smoke detector contains a sensing chamber consisting of two electrically charged plates (one positive and one negative) and a radioactive source for ionizing the air between the plates. Products of Combustion particles are produced (<0.3 microns). No visible smoke or detectable heat. May occur for milliseconds or days. Provides earlier detection than other detectors such as thermal detectors.
- 20. FIRE DETECTION AND ALARM SYSTEMS 2. PHOTOELECTRIC SMOKE DETECTORS A refractory photoelectric smoke sends an alarm when light reaches a sensor after reflecting off smoke. •Photoelectric smoke detection works on all types of fires and usually responds more quickly to smoldering fires than ionization smoke detection. •Photoelectric smoke detection is best suited for areas containing overstuffed furniture and other areas where smoldering fires can occur.
- 21. FIRE DETECTION AND ALARM SYSTEMS HEAT DETECTOR Ideally suited to locations where high sensitivity is required for change in heat and where smoke detectors are found unsuitable response temperature of a heat detector should be a minimum of 29°C above the maximum ambient temperature likely to be experienced for long periods of time Fixed temperature heat Detector Types of Heat detectors Rate of rise heat detector
- 22. FLAME DETECTORS (NFPA 3.3.65) A flame detector is a sensor designed to detect and respond to the presence of a flame or fire. There are three basic types: •Those that detect light in the ultraviolet wave spectrum (UV detectors). •Those that detect light in the infrared wave spectrum (IR detectors) . •Those that detect light in both UV and IR waves. UV DETECTORS Fire alarm gets activated when a set threshold value gets exceeded. Good for Hydrogen and methane fuelled flames. IR DETECTORS Requires the flickering action of a flame before it activates to send an alarm. Good for hydrocarbon based flames. Effective in monitoring large areas, such as an air- craft hangar or computer room COMBINATION DETECTORS Previously described detection devices may be used in a single device. Both UV “AND” IR sources must be present and exceeding their threshold levels to activate the alarm. They are also easily activated by such nonfire condi- tions as welding, sunlight, and other bright light sources FIRE DETECTION AND ALARM SYSTEMS
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- 25. CHOICE OF DETECTORS • Computer / EDP centre / other electronic equipment which have high a value should be protected by smoke detectors or combination of smoke and heat detectors (multi criteria). • Heat detectors are suitable in areas where heat producing equipment like kitchen, pantry etc. • Flammable liquid storage area, where chances of rapid heat build- up exists like garages, repair shops, battery rooms etc., heat or Flame detector should be used. SITTING AND SPACING OF DETECTORS 1. Under flat ceilings, the horizontal distance between any point & the detector shall not exceed 7.5 m in case of smoke detector and 5.3m in case of heat detector. 2. Detectors shall not be mounted within 500 mm of any walls, partitions or obstructions to flow of smoke, such as beams and duct work. 3. Ceiling obstructions like beams are deeper than 10 % of the overall ceiling height shall be considered as a wall. That is each bay shall be treated as a separate enclosure. 4. Detectors shall not be mounted within 1.0 m of any air inlet or forced ventilation system. 5. Voids as in false ceiling / flooring is more than 800 mm shall be protected with detectors with spacing like normal installation. 6. Bathroom, lavatories, WC etc., need not be protected 7. For irregular shaped areas, the spacing between the detectors and any point of the area is not greater than 0.7 times the determined spacing FIRE DETECTION AND ALARM SYSTEMS
- 26. SELECTION & DESIGN AS PER IS:2189 HEIGHT LIMITS 1. Smoke detectors can be used height up to 10.0 m 2. Beyond 7.0 m height Heat detectors are not allowed 3. Beyond 10.0 m height – Only Beam detectors or Aspirating type detectors shall be used. 4. Optical Beam detector shall be installed at every 15.0 m. FIRE DETECTION AND ALARM SYSTEMS
- 27. SPACING AS PER BS:5839 1. Under flat ceiling, the horizontal distance between any point in protected area and the detector nearest to that point should not exceed: • 7.5 m if the nearest detector is a smoke detector • 5.3 m if the nearest detector is a heat detector 2. Corridor not exceeding 2 m width: • 15.0 m for Smoke detector • 10.6 m for Heat detector 3. Ceiling obstructions, such as structural beams, greater than 150 mm in depth and deeper than 10 % of the overall ceiling height should be treated as walls FIRE DETECTION AND ALARM SYSTEMS
- 28. MANUALLY ACTUATED ALARM-INITIATING DEVICES (NFPA 3.3.102) Manually actuated fire alarm boxes, commonly called manual pull stations, allow occupants to manually initiate the fire alarm signaling system. Manual pull stations may be connected to systems that sound local alarms, off-premise alarm signals, or both. Manually operated alarm-initiating devices may look slightly different, but all are important tools for signaling emergencies. According to NFPA® 72, the pull station should be mounted on walls or columns so that the operable part is not less than 42 inches and not more than 48 inches above the floor. Single-action pull stations require only a single motion to trigger an alarm A double-action pull station has a panel that must be lifted so the operator can access and operate the pull station. FIRE DETECTION AND ALARM SYSTEMS
- 29. FIRE DETECTION AND ALARM SYSTEMS POSITIONING 1. Manual call points shall be located that, no person has to travel distances of more than 30 m to reach them. 2. Manual call points shall be located preferably near entry to staircases at every level. 3. When manual call points are also installed external to the building, the travel distance shall be 45 m. 4. Where necessary, the travel distance may require to be reduced to less than 30 m, where there is difficulty in free access or potentially dangerous risks. 5. Call points shall be fixed at a height of 1.4 m above the surrounding floor level.
- 30. BIBLIOGRAPHY Books NFPA 72 NBC -2016 IFC - 2018 Websites https://www.facilitiesnet.com/lighting/article/Occupancy-Sensors-Passive-Infrared-Ultrasonic-and-Dual-Technology--9608 THANK YOU