Emergency lighting an essential service
Monday, 17 December, 2007
Emergency lighting is an essential service that is quite often forgotten until an accident or catastrophe happens. In the past, it's been fires. Today, the threats can be far more sinister and this highlights the need for emergency lighting maintenance and evacuation procedures to be regularly conducted to be prepared in the event of such an emergency.
In the September 11, 2001 New York World Trade Centre tragedy, the occupants had minutes, not hours to escape. Most escaped in darkness. Emergency lighting provides the illumination that enables people to see clearly, to avoid obstacles and to be able to move faster and more confidently to the nearest exit and to safety in a crisis.
A forced evacuation from a building is not easy, that's why evacuation procedures are mandatory in workplaces in Australia. Should a sudden crisis occur, the occupants of a facility will travel much faster down adequately illuminated pathways with well illuminated emergency signage. It is therefore imperative that the emergency signage is easily understood.
The emergency 'Exit' luminaire has recently changed to the international standard of pictograms. This new international standard displays an arrow pointing the way and a man hurrying to the nearest egress point. This is a truly universal sign that is to be adopted worldwide.
It is a requirement that emergency luminaires are positioned correctly to ensure adequate lighting is always available in an emergency. The emergency luminaire must be installed on a lighting circuit and derive its supply from a permanent active supply. It is essential that the emergency lighting is installed, routinely inspected, regularly serviced and maintained by qualified electrical personnel.
Emergency lighting is an essential service and periodical maintenance is mandated by the Building Code of Australia (BCA) and Australian Standard AS 2293 for building compliance. A number of manufacturers including M+H Power Systems Bardic have developed self-testing units to provide a cost-effective way to ensure the required tests are routinely performed to meet the criteria prescribed by BCA and AS 2293. The testing procedure is performed automatically every three months; at the completion of the test a report is generated by a series of signals from a dedicated yellow LED located on the side of the emergency luminaire.
These performance tests do not disrupt the occupants of the facility or the fabric of the building. It also ensures that the emergency lighting functions correctly in a sudden crisis by switching the emergency luminaire on.
The performance tests can also be performed manually at any time, by just pressing the test switch located on the emergency luminaire twice within a three-second period.
The self-testing unit tests the luminaire automatically by simulating a mains power failure. The test procedure disconnects the mains supply through an onboard relay so that the emergency luminaire is illuminated and powered from its own in-built battery source.
While the emergency luminaire is illuminated and the automatic self-test is in process, the in-built battery is slowly discharged. Once the test is completed, the mains supply is restored and the battery is trickle charged to full capacity. The cyclic effect of a slow discharge and then a trickled recharge increases the life of the batteries and the performance of the emergency luminaire.
To comply with the requirements of AS 2293, the emergency luminaire must provide the correct illumination for a period of at least 120 minutes on initial installation and 90 minutes thereafter.
Once the emergency luminaires' self-tests are completed, the results are recorded in the building's emergency lighting logbook and then the emergency lighting is deemed in compliance with AS 2293.
As it is never known when the emergency lighting may be called upon, the automatic self-testing of emergency luminaires, together with periodic maintenance procedures, virtually guarantees that should a sudden crisis occur, the emergency luminaires will function correctly and illuminate the area to facilitate easy egress of the building. The illumination from these emergency luminaires enables people to see clearly, and move faster and more confidently to the nearest exit and to safety.
It's little wonder that emergency lighting is such an essential service.
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