Emergency Lighting System - Case Study Example

TABLE OF CONTENTS CONTENTS PAGES Introduction 2 Emergency Exit in the Homes 2 Testing Emergency Lights & Exit Signs 3 Types of System 4 Emergency Luminaire’s 5 How Much Light 6 Sitting of Luminaire’s 6 Servicing & Testing 7 Routine Inspection 8 Commissioning Certificate 9 Maintenance 9 EMERGENCY LIGHTING SYSTEM. Introduction. An emergency lighting system are lighting system which are mainly used in emergency situations when a building’s main power supply fails either as a result of a fire or a power cut. This abrupt power cut may lead to total darkness which may cause panic and lead to unnecessary movements hence collision and physical danger for the occupants. The emergency lightning system should always operate automatically and should give a sufficient illumination that enables people from the minority group such as the disable, infants and the old aged to evacuate safely. Most modern buildings have an emergency lightning system in place and the design and type of equipment to be used can only be specified by a registered architect, local authority or a property consultant. Emergency Exit in the Homes During a 1987 residential fire in phoenix where a family of four who were living there were instantly killed. This was later on found that they had installed some security bars over their windows. This calls for fire safe bars to be installed with a single action release device whenever security devices are being installed over emergency exiting. There must be some special considerations if the home has infants, young children, disabled or the elderly who are likely to seek help during an emergency, this may be aided by creating a unique home fire escape plans that involves all those underprivileged. It is important to plan up a home fire escape plan and this may be achieved by drawing up the floor diagram of the house and noting the regular and emergency escape routes with each and every room at least having two exit routes to be used in the event of a fire outbreak within the house. Members of the family should be acquainted with the operation of the exit routes and any faulty emergency panes should always be repaired the sooner the better. Family members need to be taught and understand that during an emergency period should the exit window get stuck, then it is wiser to use a very hard object to break it and thick clothing materials may be placed over the sharp edges of the broken glass to protect against the cuts when exiting. Some of the proven safety procedures when exiting in an emergency situation may involve; sliding out the feet and the stomach first, you should hang on with both of your hands and last but not least you should try and bend the knees while landing. Away from the house, a unique location may be established and it should be known & shown to all the family members, this removes fear from family members wondering where are the others and it will also help in restraining them from going back to the burning house to look for the loved one which is even riskier. There should be a point person in the family who will be responsible for reporting the emergency situation and should anyone be found missing it is important that the fire department should be notified as soon as possible on the possible whereabouts and no family member should be allowed to go back to the house whatsoever. It is important that the home escape plan is practiced by the family often and this may be aided by installing a monitored smoke alarm that relays information automatically to the fire department even when home occupants are asleep or away from the house. Testing Emergency Lights and Exit Signs. Emergency lights installed within business premises are just ordinary electrical devices that come integrated with a small battery as their backup source of power. The device may be connected to the buildings mains supply which may aid in recharging the backup battery and during a power failure the circuit is automatically triggered to activate the lights which eventually warns all the occupants by either blinking or lighting in a unique manner. On average they work on up to thirty minutes from the initial power blackout. Exit signs work by using the same principle, the only notable difference is that they come bundled with a twin bulb set, one is usually on all the time and operates at the buildings AC voltage and the other will light up whenever a power failure has been detected and it operates at a much lower DC voltage and they may sometimes not work at all during emergencies because there is a very high likely hood that they have probably been burnt out due to the high voltage from the mains power supply. In modern buildings emergency systems have been backed by the emergency power generators and their testing is routinely performed whenever that of the generator is being performed by the assigned contractor. The fire code also requires that the emergency systems should be at least Inspected & tested at every calendar month which must include a mandatory thirty second testing of the emergency lighting system and an annual testing should be performed on the emergency lights for at least thirty minutes on their emergency mode. Most of the emergency systems may be tested by triggering their built in “Push to test” button that their manufacturer bundles them with. In order to ascertain that the system is in a proper condition, they will be bright and uniformly lit for the entire testing period which should be at least thirty seconds, and should they dim or some lights go off then there is an urgent issue that will need to be addressed urgently. The lights may also be tested by locating the fuse or circuit breaker within the emergency systems, turning them off and carefully observing if they are going to work within the prescribed testing period which should be at least thirty seconds if it is a routine monthly test or the thirty minutes if it is an annual testing period. It is critically important to test the light for at least thirty seconds per month since defective batteries will only maintain enough electrical charge to be used up by the electrical bulbs for only a few seconds. Types of System. The emergency lightning systems have different categories such as the: Non-Maintained: These illuminate whenever there is a mains power failure. Maintained: These illuminate consistently at all the times whether there is an emergency situation or not. Sustained: These are fitted with a twin set of lamp. One operates on 110/240 AC voltage and the other runs on DC voltage in the event of the AC mains failure. The systems together with their emergency duration are usually abbreviated so as to give a proper distinction whenever making a purchase or an installation, these may include: M4-Maintained System, emergency duration is 4 hours. NM3-Non-maintained system, the emergency duration is 3 hours. S2-Sustained system, Emergency duration is 2 hours. Emergency Luminaire’s. It may be of the self contained type whereby all its components are integral within the body or slave to a central system whereby it is only the lamp that is on the luminaire body and the power supply is from a different central source. The self contained type may possess advantages such as the: Low cost and easier installation. It is possible to use a standard wiring material. Its maintenance cost is very low since it requires only some periodic cleaning on the surface and some general testing. No need of sub circuit wiring. Hardware equipment cost is very low since there is no need for extended wiring. Disadvantages: Their operating range within the environment is very limited due to the ambient temperatures which might affect the batteries. Battery life is always limited. The testing of Luminaire’s needs to be done on an individual basis. Central type advantages Its routine testing and maintenance is easier since there is only one location to be considered. They come with a superior battery performance which may be anything between 5-25 years. They can operate at very high or very low temperatures hence absolutely stable. They are less expensive since large batteries are cheaper per unit of power. Disadvantages They are expensive to install due to the cost of the equipment and wiring. Whenever the battery or the wiring circuit fails a large part of the system may be disabled. There must be a battery room to house the cells and the charger circuits which may require the ventilation of the acid gases. There could be a voltage drop on the luminaire wire which is the furthest from the battery which could cause the emergency system to be inconsistent. However, the question of deploying which type of luminaire equipment is usually based on cost factors. If a particular installation requires longetivity and low maintenance in the long run then the expensive cost of installing a central battery is acceptable on a project of a large magnitude but when it comes to smaller projects then the self contained luminaire is the most preferred. How Much Light. BS5266 have recommended that there should be some level of horizontal illumination within the floor level which the escape route should not be less than 0.2 & 0.5 lux minimal for the areas described as anti panic. Fifty percent of the room should be lit to a minimum of 0.1 lux, but the actual degree of illumination should be related to how the building has been designed and the types of occupants with factors such as age, is it a hospital, pub, supermarket or a discotheque. Sitting of Luminaire’s Proper consideration need to be given on sitting of the lighting units and the exiting signs within the premises so as to form a strong basis on the selection of the equipments to be used. The equipments should be located in such a way that they clearly show the exit routes which leads to final exits within the premises and whenever the exits are tricky to identify then there should be at least a sign directing people to the exit which also special attention should be given to areas such as the stairways, lifts, toilets, changes in level of corridor and control rooms just to mention a few and also access to the fire alarm points and the fire fighting equipments should be clearly labeled and properly illuminated. There are legislation within the United Kingdom and the rest of Europe on the requirement of emergency lightning and particular areas it should cover. The emergency lighting system should at least cover the; escape routes, emergency escape signs, changes in floor level, each of the exit doors, fire fighting equipments & fire alarm focal points, equipments that have to be shut down in case of an emergency and last but not least lifts and other areas which are in premises that are greater than 60m2. However, it may not be necessary to provide individual luminaire for each of the above but the overall lighting should be sufficient enough to enable them to be visible during an emergency situation. Servicing & Testing. In the testing of an emergency lightning system there should be simulation of a normal power failure within the lightning circuits, this automatically triggers the emergency lightning system to get into action and start using the backup power. This process may be performed either manually or automatically. Manual Testing: This may be performed by manually disconnecting the circuit either by using a switch or unplugging the electrical cable. However, within the non-maintained system, there is a central switch for the whole circuit within the building or there may be different switches available for the different circuits in the building therefore when you simulate the mains failure you have to go round the entire building checking whether the emergency lighting system are properly functioning and when the mains have been restored you have again have to walk to see that they are properly re-charging. Finally, after the test, it is recommended that the performance of the emergency system should be logged. Automatic Testing: Manual testing comes with lots of disruption and may cost a lot of the engineers time therefore the testing of the Luminaire’s may be automated. The automatic systems have a main control panel with a remote unit per luminaire which reports back to the main panel which can hold up to 500 Luminaire’s and each of the remote units may be configured in such a way that they are maintained or non-maintained for some specified periods and the frequency of the tests to be conducted may also be set. There may also be restrictions on testing. All activities can be logged on the main panel and may be printed by the systems printer upon request, the logs may have up to 1000 entry capability and the system could be battery backed. The systems information is always stored in the EEPROM which means they are preserved even when the battery power supply dies out. Some systems even come embedded with serial ports that enable modem connection to a central station where they can be remotely monitored on a regular basis. The system should come with features for testing its conditions, and additional issues need to be addressed which may include: The staff available to perform the testing should be thoroughly vetted. The level of difficulty involved in performing the tests. The discharge test should be performed outside the normal working hours of the building so as to avoid disruption on the activities within the building. Finally all the information pertaining to the tests should be properly documented Routines Inspection & Tests. Due to the risk of a possible failure occurring on the normal lighting supply shortly after the tests have been conducted, a complete duration test should be performed before a time of low risk to allow for the battery re-charges just in case of a temporary blackout. There should be daily inspections on the indicators of the central power supply. On a monthly basis the results of the short test need to be recorded and the following procedures may be used in carrying out the test. The Luminaire’s and the internally illuminated exit signs should be set to their emergency mode so that they are able to use the battery power supply, this is going to depict a normal power failure situation and we will be able to observe the period that each lamp is able to sustain itself. The proper operation of the system monitors shall be observed within the central battery systems. Annually whenever the automatic testing devices have been used, the results should also be properly documented which may also involve: Ensuring that the luminaire and the illuminated signs are tested on a monthly basis in accordance with the manufacturer’s instructions. The normal lighting should be restored and this sign should be indicated by the emergency systems in place and their charging system should be properly checked if they are functioning efficiently. The test date and results should be documented on the systems book. Commissioning Certificate. There are set out standards particularly within the European Union that demand written declarations of compliance that must be available within the site for inspection, these may include: Installation Quality: The IEE regulations must be conformed to. Photometric Performance: There should be some evidence of complying with the light levels and this has to be proven by the system designer. Declaration of a Satisfactory Test of Operation: This requires that all the system test and results should be properly documented and all the logbooks test & commissioning forms to be provided by the manufacturer of the devices. Once the installation of the emergency system has been completed then an Installation Certificate will be issued by the installer of the system to the occupier or owner of the premises. Maintenance. In order to ensure that the system is fully operational, there should be routine servicing and logging of all the performance and in case of consumables such as the replacement lamps and spares then they should be readily available for use. Read More