Emergency lighting

In the event of a system breakdown, disaster situations and similar awkward situations, no one likes to find themselves in the dark. Particularly dangerous situation is to find yourself in the dark of an unknown object. In order to avoid such a situation and enable operations related to security measures, emergency lighting systems are installed in buildings. It is part of the life safety systems. This system is difficult to spot for a normal building user until the electricity goes out and the regular lighting goes out. Which means that the emergency lighting has two power supplies. So that when the primary power is turned off, secondarily (which is independent of the primary) it allows the emergency lighting to illuminate important areas.

The most famous pictogram on the signal signs of emergency lighting is the green man. In the picture of the pictogram, without the need to know a certain language it is easy to notice that the exit is indicated and thus does not set a language barrier. The world-famous pictogram was designed by Japanese Yukio Ota in the late 1970s for a competition by the Japan Fire Protection Association. And the 1985 design was accepted as an ISO standard for the evacuation direction label (ISO 7010).

Legislation

Emergency lighting is designed if required by law in Croatia on the basis of the Ordinance on fire resistance and other requirements that buildings must meet in the event of fire. According to the above regulations, a more detailed description of the application is described through the standard HRN EN 1838 Lighting applications – Emergency lighting, HRN EN 50171 – Central power supply systems and HRN EN 50172 – Systems Emergency escape lighting systems. Safety signs of evacuation direction on lighting fixtures should be according to ISO 3864-1, ISO 3864-2 and ISO 7010.

According to HRN EN 1838, the emergency lighting is divided as:

Escape route lighting has the task to assist the safe exit from a location for occupants by providing appropriate visual conditions and directions finding on escape routes and in special locations, and to ensure that firefighting and safety equipment can be readily located and used.

Safety signs are emergency lighting on escape routes with the task to provide appropriate visual conditions and direction finding to assist escape routes to be readily located and used.

Open area (anti-panic) lighting has the task to reduce the likelihood of panic and to enable safe movement of occupants towards escape routes by providing appropriate visual conditions and direction finding. The flow of light for escape routes or open areas should be downward to the working plane but illumination should also be provided to any obstruction up to 2 m height above that plane.

High task area lighting has the task to contribute to the safety of people involved in a potentially dangerous process or situation and to assist proper shut down procedures to be carried out for the safety of other occupants of the location.

System implementation

There are three possible implementation versions of this life safety system, and they are:

• Lamps that contain their own batteries (SELF-CONTAINED MANUAL TESTED)
  • Luminaires connected by a single cable to the mains
  • Suitable for systems where fewer luminaires are required (size range <40 luminaires)
  • When maintaining this system, it is mandatory to periodical check each individual lighting fixture
• Lamps that have their own batteries and are centrally monitored (SELF-CONTAINED AUTOMATIC TESTED)
  • A lamp that connects with two cables. These are mains power and monitoring lamps
  • When maintaining the system, tests are performed automatically, which minimizes the need for human resources
• Lamps that are connected to a central battery system and centrally monitored (CENTRAL BATTERY SYSTEM AUTOMATIC TESTED)
  • Possibility of powering the lamp with one cable
  • In order to reduce the possibility of the system not working in the event of a fire zone accident, two independent lighting supply circuits and a fireproof cable are required.

System implementation selection

Each type of design has advantages according to which it is determined for which application a particular design is selected. For such a decision it is necessary to consider all the parameters that affect the cost of ownership of such a system, and these are: 

• The amount of lamps needed 
• Capital cost of installation 
• Testing costs 
• Maintenance costs 

The following figure shows the total cost of ownership, which includes capital and operating costs for all three emergency lighting designs over a period of 10 years.

After selecting the type of emergency lighting, it is necessary to correctly select the lamps and their arrangement in the space it illuminates. The design solution is influenced by the profile of the user of the building, the purpose of the building and the complexity, i.e. the size of the building. With calculation it needs to be checked if the number of lighting planned to be installed will give sufficient amount of light output demanded by the standard. But it is always necessary to take into account objects that may be an obstacle to the light beam of the lamp (such as other installations). Examples of important places that need to be illuminated with the emergency lighting are: evacuation route, location where the direction is changed, staircase, firefighting equipment, call points, first aid stations, outside the exit of the evacuation route, etc.

Normal luminaires can serve as part of emergency lighting with an additional module that provides power in the event of a loss of primary luminaire power. This additional module allows the lamp to have a stand-alone extra battery or to be connected to a central battery system. One example of an application is when the emergency lighting is retrofitted to a building.

In complex buildings where the installation of a central monitoring system is recommended, there is possibility to chose luminaries that can change the direction of the evacuation safety signs depending on the location of the accident in the building. This redirects the person trying to evacuate via a disabled / destroyed route to a route that is not the shortest but is safe.

Lights test

Emergency lighting that has a central monitoring system has addressed all the lamps and performs automatic tests that should be saved on a monthly basis. They must be performed according to the standard Automatic test systems for emergency lighting powered by batteries HRN EN 62034. Emergency lighting without a central monitoring system should be tested by a person authorized by the owner of the building and should be carried out conscientiously and record the results tests. Tests are divided into daily, monthly and annual and should be performed according to HRN EN 50172.

When designing emergency lighting, the building should be considered as a whole in order to take into account all the risks that may affect the safe evacuation of the building. There is no emergency lighting system that suits all types of buildings, because of that it is tailored designed for each separate building. Since this system is intended to save lives and does not bring economic added value, it is important that the system is reliable and energy-intensive. When choosing equipment, the possibility of purchasing spare parts and the availability of trained service technicians should be taken as an important factor.