Valuable Information Regarding the Fire Alarm System - Essay Example

FIRE ALARM SYSTEM CHAPTER ONE INTRODUCTION: Nothing is valued more important in the world than safety of life. People can get trapped in different situations for which they are sometimes prepared and sometimes not. For this reason it is always better to chalk out an emergency plan before one actually finds himself trapped in an emergency. When a fire breaks out in a building the first and foremost priority is the safety of the occupants. A quick method must be adopted to inform the occupants and the people around about the coming danger. With the presence of an early warning system it becomes a lot easy for the occupants to respond to the call and evacuate the building well before the situation actually gets worse and beyond control (Types of Fire Alarm Systems, n.d.). A well developed pre arranged plan is always advisable in such situations. In case of a fire break out a simple plan of evacuating the building, fire fighting and calling the fire department must be dealt with amicably. With the advancement of technology these functions can easily be performed by a fire alarm system in the building. Although it is mandatory for every large or small building to have a fire alarm system yet it is determined by the fire risk assessment carried out by the owners, occupants, employer or who ever is responsible for the safety of the building and its inhabitants (Types of Fire Alarm Systems, n.d.). For safety purposes it is always essential to have a fire alarm system in all the buildings other than those small places that are open and where fire can be easily detected and inhabitants can be informed by word of mouth or by instruments operated manually (Types of Fire Alarm Systems, n.d.). In this paper I intend to explore in detail some valuable information regarding the fire alarm system. The aim of this paper is to: Define the fire alarm system Understand the fire alarm system Understand the fundamental design of the fire alarm system and Study the different types of the devices in detail, their utility, advantages and disadvantages. I intend to discuss each topic in separate chapters for a proper understanding of the device. At the same time the advancement in technology must be appreciated for helping human kind in overcoming emergency situations. Before going into further detail of how does a fire alarm work and what are the different types of the device it would be pertinent to define the device in an appropriate manner for further understanding of the fire alarm system. A fire alarm system is defined as an active fire protection system that is designed to detect fire, traces of fire or the effects of fire. Due to its design it has the capability to notify the occupants in the building, people around the building, the fire department and activates all the fire controlling devices in the building. A simple fire alarm system may include an alarm initiating device, alarm notification device, fire safety control devices, and power supplies and wiring (Cote, 2000). References: Cote, A. E. (March 2000). “Fire Protection Handbook eighteenth edition”. National Fire Protection Association, pp 5-7. “Types of Fire Alarm Systems”, (n.d.). Retrieved on February 13, 2008 from http://www.usfa.dhs.gov/downloads/pyfff/alarmsys.html DESIGN AND FUNDAMENTAL DESIGN OF THE FIRE ALARM SYSTEM CHAPTER TWO AIM: The aim of this chapter is to: Discuss the design and fundamental design of the fire alarm system DESIGN: The design of the fire alarm system is carefully chalked out by competent engineers who are educated in fire protection and are licensed to practice their knowledge within a particular area as defined by the administration of a particular country or province etc. These engineers carefully design the device for active fire suppression, controlling lighting and electrical power etc. Fire alarm system is planted in the building keeping in view the design of the building. Further details are covered by the technician hired by the contractor. In the United States it is essential to hire a technician for fire alarm design who has been licensed by the National Institute for Certification of Engineering Technologies. The design has to fulfill the recommendations set for the model building code having jurisdiction in that area. In the United States the National Fire Alarm Code is usually followed for the design, installation and maintenance of the fire alarm system (Cote, 2000). FUNDAMENTAL DESIGN: A simple fire alarm system is made up of the following components: Initiating device: They have the capability to keep the device in alarm state. Examples include photoelectric smoke and heat detectors, simple heat detectors, Ionization heat detectors, in-duct smoke detectors, pull stations that are manually operated and sprinkler water flow sensors (Herres, 2006). Initiating devices are linked to the control panel by a 2 or 4 wire initiating device circuit. In case of limited power system 24V DC is provided to the initiating devices that are wired in parallel. The wires are not grounded and are isolated from EMT which is grounded through the connector at the control panel. The voltage provided in this manner is used to evaluate the state of initiating devices and wiring (Herres, 2006). Fire alarm system has a number of initiating devices which are based on different zones. The initiating devices are connected to the control panel through the initiating device circuit (Herres, 2006). Indicating Appliances: The purpose of indicating appliances is to make the people aware of the fire break out when the system enters the alarm state. The warning is made through horns, bells, chimes, strobe lights or combination units. They are also available in weather proof and hazardous location versions (Herres, 2006). Control Panel: This is the brain of the whole system. NAC Power booster is the most prominent example in this regard (Cote, 2000). The control panel consists of programming and operating electronics and user interface. It is fed by standard branch circuit wiring and has replaceable circuit cards for each zone. The operating electronics consist of alphanumeric display which indicates the state of the system and other information relating to the emergency, a touch pad system so that the person operating the alarm can silence it, reset and reprogram it once the emergency is over (Herres, 2006). The fire alarm system consists of the following parts: Primary power supply- includes commercial power and secondary power supply includes sealed lead acid batteries. Generators are used only under guided rules (Cote, 2000). Notification Appliances- They provide stimulus for initiating an alarm so that necessary information may be provided to the user, concerned personnel and occupants. Examples in this category include bells, siren, horn, speaker, lights, text displays and other audible and visible out put (Cote, 2000). Signaling line Circuits- SLC are the wires which transfer the data (Cote, 2000). Supervisory Signals- They have the capability to identify any problem in the system that could prevent the fire alarm from functioning. For example if there is a closed water valve the supervisory signals will detect it and notify it immediately (Cote, 2000). Trouble Signal- Trouble signal indicates any defect in the wiring system. For example a disconnected wire from the heat system can be detected by the panel and the user can be informed through trouble signal (Cote, 2000). Remote Annunciation- It is an alpha numeric display which mentions the place from where the alarm originated. It is a very useful device for the emergency personnel to detect the location of the fire. They may also carry such devices that may help in silencing or resetting the alarm. The device is key pad controlled (Cote, 2000). Auxiliary devices include remote annunciators with LEDs that display the state of the system. There is also a switch to silence the alarms along with a visual LED indication of the zone which initiates the fire alarm. Electromagnetic door holders are also available which when needed de energizes the magnet and shuts the door which can be opened manually after wards (Herres, 2006). Batteries: Sealed batteries are used in fire alarm systems which are similar to the ones used in emergency lights. Usually 6V batteries are used that are wired in series to make a 24V direct current for a power limited system. The batteries can be placed in a controlled panel or in a separate enclosure. Once the AC power fails the batteries start operating with no disturbance in the fire protection system. There is also a charger to recharge the batteries (Herres, 2006). It is very important for every one to understand the basics of fire alarm system. Everyone should be able to reactivate the fire alarm so that the provision of fire safety alarm should continue to work for further emergency situations. The modern fire alarms are designed in such a way to detect smoke, small flame, water flow in a sprinkler or a manually pulled lever of a pull station. Since they are linked to the concerned department the information and warning can be provided to the occupants without further delay (Herres, 2000). Recent advancement in the fire alarm technology has made life a lot easier. With the introduction of the addressable head the exact location of the fire can be detected without any waste of time. This system has enhanced a diagnostic capability which is a great achievement. References: Cote, A. E. (March 2000). “Fire Protection Handbook eighteenth edition”. National Fire Protection Association, pp 5-7 Herres, D. (2000). “Understanding Basic Fire Alarm Systems”, Retrieved on February 13, 2008 From http://ecmweb.com/mag/electric_understanding_basic_fire/ UTILITY OF FIRE ALARM SYSTEMS CHAPTER THREE AIM: The aim of this chapter is to study in detail: The usefulness of different types of alarm systems which will further highlight the need to have a fire alarm in residential complexes, office buildings and even small areas. The chapter will discuss the need of different types of fire alarms for different types of areas. Fire alarm systems are very useful. They are installed for the protection of life and property. With the presence of a good fire alarm system a place can be secured from damage and also valuable life can be saved. Fire alarm systems are designed according to the suitability of the place. There are different types of alarms for large and small areas. SMALL AREAS Usually in small areas it is not necessary to have an expensive equipment to warn the people about emergency. In a single story building where people work close to each other a simple shout calling “FIRE” can warn the people about the emergency. However one has to keep in mind that the call should be loud enough to be heard by everyone including those working in other rooms, roof and toilets. For this purpose it is always advisable to use manually operated sounders which include hand bells or rotary gongs etc. A simple call point connected to a bell is also suitable in such situations. However it must be kept in mind that the manually operated system must be placed in a way that is easily accessible to everyone. At the same time it should be located at a center point from where it is audible to everyone. Ideally there should be more than one alarm in any building (Types of Fire Alarms, n.d.). ADVANTAGES AND DISADVANTAGES: Purely manual alarm system may include hand bells, whistles, strikers, rotary gongs and hand operated sirens. These types of fire alarms have the advantage of being readily available and are also of low cost. There are however some disadvantages of such type of alarms. Some disadvantages include: Such types of alarms are only audible at a limited place The siren will sound only as long as it is in operation The person operating the siren will not be in a position to participate in other activities (Types of Fire Alarms, n.d.). LARGE BUILDINGS In larger buildings it is important to have an alarm system that operates at a larger level for the safety of the inhabitants of all the flours of the building. In such places a manually operated electrical alarm system having connection with the main power supply is essential. There should a back up battery system which is automatically turned on in case of power failure. ADVANTAGES: There are a number of advantages of this system. Once manually operated, the alarm will continue to sound unless it is turned off by the operating person. These types of alarms are clearly audible throughout the building and work without the operator thus making him free for other emergency evacuation activities (Types of Fire Alarms, n.d.). DISADVANTAGES: High cost and regular maintenance of such devices are some of the disadvantages of these devices (Types of Fire Alarms, n.d.). RESEDENTIAL FIRE ALARM SYSTEM Residential fire alarm system is a fire detector device that often performs functions other than detecting fire. The residential fire alarm system performs a number of functions such as burglar alerts other than providing fire protection to the house. Such a system identifies traces of burglary and informs the police or fire department. It is installed at places near the windows and doors where there is danger of breaking in. The system is attached to the central control panel which detects the smoke and raises an alarm. For burglary detection it has sensors that detect motion or body heat. It is usually linked with the primary electric supply but often has back up batteries that can operate up till 24 hours. Occasionally fire alarm systems often provide assistance to disabled people as well. For instance if a disabled person needs help he can trigger the fire alarm through the radio transmitter he carries. Signals received at the help center are identified as burglar, fire or medical aid and action is taken accordingly (Fire Alarm Systems n.d.). Residential fire alarms are also available with blinking lights equipment for those people who have problem in hearing. It is always important to replace the batteries after a few months to enable smooth working of the equipment (Turner, 2007). Upon detection of heat, smoke or motion the residential fire alarms are turned on which helps the occupants to evacuate the building before the situation gets worse. Fire alarms must be tested after a certain time period to avoid emergencies. It would be pertinent to discuss some prominent advantages of the residential fire alarm. ADVANTAGES OF RESIDENTIAL FIRE ALARM SYSTEM: It is very important to have a residential fire alarm system because every year property worth millions of dollars is damaged because of the lack of a residential fire alarm system. The damage to property and life can be prevented with the installation of a residential fire alarm system (Turner, 2007). Another advantage of a residential fire alarm system is the increased reliability and its portability. The alarm can be placed anywhere where the need is felt. Most people install the residential fire alarm system to detect burglar activity. The additional feature of fire detection is always appreciated (Turner, 2007). Another important feature of the residential fire alarm system is the fact that help can be provided according to the need of the occupants of the house. For example in case of a burglary the alarm will detect motion or body heat and inform the police department. In case of fire breakout the message is conveyed to the fire department and in case of medical aid to a disabled person help is provided accordingly. The remote monitoring service keeps all the information about the occupants of the house and incase of fire break out the message can be conveyed to the fire department and help can be sent accordingly (Fire Alarm Systems, n.d.). References: “Fire Alarm Systems”, (n.d.). Living With Fire, Retrieved February 15, 2008, from http://www.ehs.uci.edu/programs/fire/firealarmsystem.pdf Turner, T. (2007, February 11). “Residential Fire Alarm-Things You Need To Know”. EzineArticles. Retrieved February 15, 2008, from http://ezinearticles.com/?Residential-Fire-Alarm-Things-You-Need-To-Know&id=450469 Types of Fire Alarm Systems”, (n.d.). Retrieved on February 13, 2008 from http://www.usfa.dhs.gov/downloads/pyfff/alarmsys.html DIFFERENT TYPES OF FIRE ALARM DETECTORS CHAPTER FOUR AIM: The aim of this chapter is to study the different types of fire alarms. A fire alarm system has different devices that help it in its operation. These devices are mentioned below: FIRE ALARM PULL STATION OR CALL POINT: Pull stations are the red boxes placed on the walls near the fire exits. They are considered to be the fastest way to alert the concerned people about the up coming danger in case of a fire break out. In a normal situation when a fire breaks out a person has to inform the fire department about the emergency and the location of the building. This of course is a lengthy procedure. At times it is difficult to locate the phone and at times it becomes difficult to give proper location of the building especially when one is not familiar with it. In this situation fire alarm pull stations are very effective since they automatically inform the fire department. They are actually linked with the fire department. Once the lever is pulled the fire department is informed and help is immediately sent to the affected area (Faulkner, 2007). Because of their easy use the alarms are usually placed in a glass case to avoid accidental pulling of the lever. They are also placed at a certain height to keep away from the reach of children. SMOKE DETECTORS: Smoke detectors detect smoke in a particular area and are of two types, ionization detectors and photoelectric detectors. Smoke alarm has either one or both detectors. At times it is also equipped with fire detector sensors. The device is operated by 9V lithium battery or 120 V house wiring. IONIZATION DETECTORS: Ionization detectors are composed of ionization chamber and a source of ionizing radiation. Source of ionization radiation consists of a small quantity of americium-241 which actually is a source of helium nuclei. The ionization chamber ha two plates a centimeter apart. The battery charges one plate positive and the other plate negative. The americium releases alpha particles and they knock off the electrons from the atoms in the air thus ionizing oxygen and nitrogen atoms in the chamber. The positive electrons are attracted to the negative plate and the negative ones towards the positive plate due to which a small amount of electric current is continuously generated. When the smoke enters the chamber the smoke particles get attached to the ions and neutralize them so that they do not reach the plate. The change in current between the plates initiates the alarm (Helmenstine, n.d.). PHOTOELECTRIC DETECTORS: There are different types of photoelectric detectors. In one type smoke can block the light beam. The reduction in light thus triggers the alarm. In some cases smoke particles scatter the light on the photo cell thus triggering the alarm. There is a light emitting diode in the T shaped chamber that throws light across the horizontal T bar. A photocell is installed at the base of the vertical base of T which generates the current upon exposure to light. When the smoke enters the light is scattered and some of it falls on the photocell at the base of vertical T bar. The alarm is triggered when sufficient light falls on the photocell (Helmenstine, n.d.). HEAT DETECTORS: Heat detectors are initiated by the rise of room temperature above the fixed temperature. Some types of heat detectors include: SPOT TYPE OR FIXED TEMPERATURE DETEECTORS: They are usually categorized as Spot types and have a detecting element that responds to the changes in temperature in a fixed place. Some examples in this category include replaceable element fixed-temperature heat detector and combination fixed temperature or rate of rise heat detector. The spot type of fixed temperature detectors are used in unattended places to detect fires which increase the temperature of the device above its fixed temperature. The fixed temperature is usually 135*F to 145* F or 185 to 200*F. Higher temperature detecting devices are kept in such places where the normal temperature is high such as the boiler rooms, kitchens and attics etc. These devices are usually functional for one time and have to be replaced once they are used. The device has a fusible metal alloy that operates the device once it is melted or fused (Integrated Publishing, n.d.). RATE COMPENSATED DETECTORS: Rate compensated detectors operate to detect temperature change up to 5* F per minute. In case of higher rate of temperature change the operator detects the rise in temperature through its design and operates faster than the normal fixed temperature detector. It can reset automatically can be used again once the temperature drops below the fixed level of the detector (Integrated Publishing, n.d.). RATE OF RISE DETECTIORS: They are designed to raise an alarm in situations where the rate of temperature rise is 15*F per minute. The air pressure is raised inside the detector once the temperature is raised. The fast increasing temperature activates the bellow type of diaphragm that is connected to the alarm which is then activated causing signal. Once the detector is activated it can be used again. However it needs to be reset again because actuation it cannot be visible detected (Integrated Publishing, n.d.). COMBINATION DETECTORS: Combination detectors are a combination of fixed temperature and rate of rise temperature characteristics. If one of these element actuates it causes an alarm. Fixed temperature element actuates only once and needs to be replaced once it is actuated. The rate of rise element is reusable and resets automatically (Integrated Publishing, n.d.). CARBON MONOXIDE DETECTORS Carbon monoxide detectors identify the dangerous level of CO at a place. The alarm is turned on once the CO level goes above the normal level (Helmenstine, n.d.). There are different types of CO detectors. They are discussed below: METAL OXIDE SEMI CONDUCTORS: These detectors are designed on the original technology of detecting CO. Reaction between heated tin oxide and CO determines the level of CO. They are connected to the house power supply (Carbon Monoxide, n.d.). BIOMIMETIC: In this detector the gel coated discs change their color in the presence of CO. The change in color triggers the alarm (Carbon Monoxide, n.d.). ELECTRO CHEMICAL DETECTORS: In these detectors a chemical reaction takes place with the CO which triggers the alarm (Carbon Monoxide, n.d.). References: “Carbon Monoxide” (n.d). Canada Mortgage and Housing Corporation, Retrieved on February 13, 2008, from http://www.cmhc-schl.gc.ca/en/co/maho/yohoyohe/inaiqu/inaiqu_002.cfm Faulkner, David. (2007, August 09). “Fire Alarm Pull Station - The Fastest Way To Call For Help”. EzineArticles. Retrieved February 13, 2008, from http://ezinearticles.com/?Fire-Alarm-Pull-Station---The-Fastest-Way-To-Call-For-Help&id=68092 “Heat Detectors”, (n.d.). Integrated Publishing, Retrieved on February 15, 2008 from http://www.tpub.com/celec/95.htm Helmenstine, A.M. (n.d.). “How Carbon Monoxide Detectors Work”, About.com, Retrieved on February 15, 2008 from http://chemistry.about.com/b/2006/12/22/how-carbon-monoxide-detectors-work.htm Helmenstine, A.M. (n.d.). “How do Smoke Detectors Work”, About.com, Retrieved on February 15, 2008 from http://chemistry.about.com/cs/howthingswork/a/aa071401a.htm SOME ADVANTAGES AND DISADVANTAGES OF DIFFERENT TYPES OF FIRE ALARMS CHAPTER FIVE Every device has its own advantages and disadvantages. Different types of fire alarm have its own advantages or disadvantages. Before installing an alarm it is very essential to go through the details since there are different types of alarms that a best utilized in situations for which they are designed. The Aim of this chapter is to identify some of the advantages and disadvantages of different fire alarm systems. MANUAL CALL POINTS Manual call points are easy to use and are very simple. The person needs to pull the lever to activate the alarm. They are the quickest method to alert the occupants of the up coming danger. They are connected to the control department which sends message to the fire department about the possible fire break out. The only disadvantage is that they are easy to use so any one can mischievously pull down the level and initiate an alarm. To protect such false alarms the manual call points are often kept in glass cases. A person has to break the glass to pull the lever down (Wikipedia, 2007). ADVANTAGES OF SMOKE DETECTORS About 60% of fire deaths occur in those places where there is no alarm. Smoke detectors save life and property. They can alarm you even when one is sleeping or is away from the place of fire break out. They provide life saving warnings well before time and allows the occupants to evacuate the place well before time. They are also inexpensive Those operated with lithium batteries can last for up to ten years (Kentucky Injury Prevention and Research Center, n.d.). Ionization alarms are considered to be fast and inexpensive than the photoelectric alarms. Ionization alarms are quick in detecting fast building fires. Photoelectric alarms are more expensive. They detect slow smoldering fires better. They are less sensitive to smoke arising out of cooking and shower. It is easy to install them near kitchens and bathrooms without any danger of false alarm (Kentucky Injury Prevention and Research Center, n.d.). HEAT DETECTORS Heat detectors are on all the time even if one is not at home. They can also work on back up batteries which is very useful in case of power failure. Because they are connected to the control department help always comes on time even when there is no one in the building to make a phone call to the fire department (Francis, 2005). CARBON MONOXIDE DETECTORS Advantages: 1. Carbon monoxide detectors have the capability to detect fire from outside the closed door of any room or cupboard even before the fire is spread. This actually helps in evacuating the building well before the escape routes get covered with smoke or fire. 2. They are capable of detecting smoke even if they are wrongly mounted on the wall or even under the floor. 3. CO detectors remain functional even at places where the thermal barriers inhibit smoke movements such as those buildings that have metal roofs. 4. They also operate in beamed ceilings which actually act as an obstruction in the way of smoke flow (West Yorkshire Fire and Rescue Service, 2006). Disadvantages: 1. The effective life of CO is approximately 5 years. 2. It is not suitable for all types of fires such as early stages of fire in electrical wires and cables. 3. It is also not suitable for such places where chemical fires are the main hazard. For fast burning chemical fires ion chamber or flame detectors are more appropriate to use. 4. They are not recommended for duct air sampling applications. 5. They cannot detect non carbon fires such as pure metal fires. 6. They do not detect smoke and fumes alone and will act only in case of combustion (West Yorkshire Fire and Rescue Service, 2006). BATTERY POWERED ALARMS ADVANTAGES: Battery powered alarms remain unaffected by the cut down in the main power supply. They can be placed anywhere even at places where there is no electrical outlet or wires (Christopherson, 2006). DISADVANTAGES: The only disadvantage is that one has to keep a check on the batteries and replace them before they actually die. The beeping sound indicating low batteries can often become irritating (Christopherson, 2006). ELECTRIC ALARMS ADVANTAGES: The advantage of electrical alarms is that one does not have to change the batteries and experience the beeping sound of low battery. DISADVANTAGES: In case of a power failure the alarm becomes useless. They need to be placed only at places where there is an electrical outlet or wiring (Christopherson, 2006). Conclusion: Fire alarms have always been installed for the safety of the precious lives of people and for the protection of the property. As mentioned above 60% of the deaths occur due to the absence of fire alarms in the building and as such the importance of such alarms become self evident. The advancement in technology has opened many ways for the security of the people. These devices must be utilized by every one for the protection of precious lives and property. At the same time a periodic check up of these devices is also very essential in order to avoid any mishap. References: Christopherson, E. (2006). “Smoke, Heat and Carbon Monoxide Detectors”, Texas Children’s Pediatric Associates, Retrieved on February 15, 2008 from http://www.aboutkidshealth.ca/HealthAZ/Smoke-Heat-and-Carbon-Monoxide-Detectors.aspx?articleID=8862&categoryID= “Fire Alarm Systems”, (2006). West Yorkshire Fire and Rescue Service, Retrieved on February 15, 2008 from http://www.westyorksfire.gov.uk/new/departments/fireSafety/nfgs/FS-NFG002-FireAlarms.pdf “Fire Alarm Pull Stations”, (2007). Wikipedia. Retrieved on February 15, 2008 from http://en.wikipedia.org/wiki/Fire_alarm_pull_station Francis, M. (2005, May 28). “Alarm System: Smoke and Heat Detectors”. EzineArticles. Retrieved February 15, 2008, from http://www.ezinearticles.com/?Alarm-System:-Smoke-and-Heat-Detectors&id=39454 “Smoke Alarms”,(n.d.), Kentucky Injury Prevention and Research Center, Retrieved on February 15, 2008 from http://www.kiprc.uky.edu/fire/satips.htm Read More