Emergency lighting

FAQ: Frequently asked questions

Emergency lighting has two functions. In the event of power failure, emergency lighting ensures that persons can leave the building quickly and safely and that emergency services can come into the building from outside. Emergency lighting is subject to legal provisions. The respective building owner is responsible for the implementation.

Different technologies are available for the implementation. A distinction is usually made between centrally and decentrally supplied emergency lighting systems.

In the case of centrally supplied emergency lighting systems, a large battery or a generator provides the energy for the emergency lighting via a specially protected supply network. Tridonic provides an extensive range of products for this area. All Tridonic LED drivers and electronic ballasts for fluorescent lamps in compliance with the EN 50172 standard can be used.

Decentrally supplied emergency lighting systems manage without an own supply network and are simpler and more flexible as a result. They consist of an emergency lighting unit, a battery and an indicator LED. Using these additional components, every luminaire can be converted into an independent emergency luminaire with only a few simple steps.
The advantages of decentralised emergency lighting systems are obvious: Thanks to installation of all necessary components in the luminaire, the expensive wiring of a central battery system is not necessary and the risk of total failure is significantly reduced by the use of many decentralised individual batteries.

There are two different operating modes for all types of emergency lighting: standby mode and continuous mode.
In standby mode, the luminaire is off while the mains power supply is available. Office applications are a frequent application area of this operating mode.
In continuous mode, the luminaire is always switched on irrespective of the mains power availability. This operating mode is frequently used for the signage of emergency exits (escape signs).


LED emergency lighting

The LED technology provides further possibilities for the integration of emergency lighting. For example, it is possible with only a few emergency lighting unit variants from Tridonic to provide an optimum solution for all common LED modules. In order to be able to cover all customer requirements, emergency lighting units are available in different variants, as manually tested devices and as autotest device with or without DALI interface.

  1. Power control for the EM converterLED
    • The focus during the development of the EM converterLED was on maximum flexibility and a lean range. Thanks to the integrated power control, the user always obtains the maximum possible luminous flux, irrespective of the LED module used. Any programming or adjustment of the current and voltage values for different LED modules is not required.

  2. Current and voltage values for the EM converterLED
    • Thanks to the power control, the current and voltage values of the EM converterLED are adjusted independently. In order to be able to determine the relevant parameters in advance, it is recommended to determine the appropriate values using the data sheet.

  3. Combined emergency lighting units
    • Combined emergency lighting units such as the EM powerLED 50 W or the EM powerLED 80 W provide an “All-in-One” solution. While mains voltage is available, the EM powerLED operates the connected LEDs with the specified current. In the event of any mains power failure, the control gear automatically changes over to emergency lighting operation. The advantages of this solution are the simple wiring and guaranteed compatibility of the components.

  4. SELV and non-SELV emergency lighting units
    • Emergency lighting units with different voltage classes are required for different luminaire types. In the case of luminaires that do not have a protective cover, the voltage must always be smaller than 60 V DC and all components used must have the specified insulation values.
      Only SELV-specified emergency lighting units are permitted to be used for luminaires in this category.
      Emergency lighting units with a higher voltage class are used for luminaires with higher LED forward bias.

  5. NiCd, NiMH and LiFePO4 variants
    • In order to be able to achieve the optimum performance of different battery types, appropriate charging and discharging processes are necessary.
      With NiCd, NiMH and LiFePO4, different battery types are available for decentralised emergency lighting systems. Thereby, it must be ensured that emergency lighting unit and battery are correctly matched with each other. An incorrect combination of emergency lighting unit and battery type can result in early failure of the battery.

  6. Which drivers can be used with the EM converterLED?
    • A LED driver can be used in combination with the EM converterLED if the limits regarding output current, inrush current, output voltage and output power do not exceed the maximum values stated in the respective EM converterLED data sheet.

  7. Which light output do I get in emergency operation?
    • An approximate light output can be calculated with the formula:

      light output in emergency operation = (LED current in emergency operation) / (LED current in mains operation) × (light output in mains operation)

  8. What does the EL and EL-T mark on LED drivers mean?
    • EL
      The LED driver is suitable for the use in emergency lighting applications. The mark is used for LED drivers for centrally supplied and single battery applications.
      Emergency LED drivers with this mark have an inbuilt automatic test function which complies with the IEC 62034.
      For further information, have a look at the technical document Emergency Lighting – EL and EL-T mark which can be found under “Technical data > Other technical documents”.

  9. How long does it take for Tridonic emergency LED drivers to switch to battery operation?
    • < 0.25 s from detection of emergency event.

  10. How are the Emergency LED drivers charging the battery?
    • Tridonic Emergency LED drivers use three different charging algorithms: Constant Current charging, Multilevel Charging, Intermittent charging.
      The different charging algorithms are further described in the document Whitepaper Batteries EM which can be found under “Technical data > Other technical documents”.


Emergency lighting with fluorescent lamps

A major part of existing emergency lighting systems is operated with fluorescent lamps. Tridonic provides emergency lighting units with different functionalities for all common fluorescent lamps.

  1. How long does it take for devices in the PC COMBO family (combined electronic ballasts and emergency lighting units) until the lamp starts in emergency lighting operation after a mains power failure?
    • Less than 200 milliseconds.

  2. Why are there four different types for EM BASIC?
    • The EM BASIC emergency lighting unit range consists of four different product types (A, B, C, D). These are optimised for the different start and operation requirements of various fluorescent lamp types. They thus ensure the best possible lamp operation and a long lamp life with a minimal number of battery cells.



  1. Warranty
    • Details about the warranty conditions for batteries from Tridonic can be found at Guarantee conditions.

  2. Ageing
    • Batteries like any other electrochemical component are always subject to ageing. The expected lifetime of the battery can be found in the data sheet of the emergency LED driver or the Declaration of Design. The precise value depends on the temperature and the number of discharge cycles.

  3. Declaration of Design
    • The Declaration of Design specifies the limit values with which the expected lifetime of the battery is achieved. There are different documents for different charging circuits. These are located in the download directory of the respective battery.

  4. Declaration of Safety
    • The safety and the chemical composition of the respective cell types are described in the Declaration of Safety. The content of this document is particularly relevant for the transport and storage of batteries. The document is located in the download directory of the respective battery.

  5. Battery Technologies
    • NiCd and NiMH batteries are mainly used for individual battery systems. The prohibition for the use of NiCd batteries is not applicable for emergency lighting applications.
      NiCd batteries are robust and economically attractive energy storage. NiMH batteries provide the advantage of significantly higher energy density. As a result, they are frequently used in luminaires where space is limited.

  6. What is the cadmium content for NiCd batteries?
    • The cadmium content for NiCd batteries is around 20 % of the total weight.

  7. Are the batteries and the supplied connection wires free of silicone?
    • Yes, the batteries and the supplied connection wires including the spade connector for the battery connection are silicone-free.

  8. Do the emergency lighting batteries have to be replaced after the design lifetime?
    • Not necessarily. The emergency lighting batteries must be replaced if the specified emergency lighting operating time is no longer achieved. The emergency lighting batteries are designed for a durability with maximum permissible casing temperature.

  9. Do the Tridonic batteries comply with the European Battery Directive?
    • Yes, the batteries comply with European Battery Directive 2006/66/EC.

  10. What does multi-level charging system mean?
    • The different charging methods are described in the document Whitepaper Batteries EM which can be found under “Technical data > Other technical documents”.

  11. What are the advantages of the multi-level charging system?
      • Lower battery temperature and as consequence a longer service life of the batteries 
      • Shorter charging times 
      • Lower power consumption 

  12. What charge state do the emergency lighting batteries have when they are delivered?
    • The emergency lighting batteries are delivered with approx. 30 % charge. The charge state reduces during storage of the batteries due to self-discharge. Depending on the storage time, the charge state can be correspondingly lower when installed in the emergency luminaire.

  13. Why do different drivers have different temperatures for batteries?
    • The different charging methods are influences on the ageing of the battery. To compensate for the faster ageing due to the charging method, the temperature is reduced for some charging methods so that we can still offer a 4 years design life.


General Information

  1. Layer structure
    • Tridonic provides emergency lighting units with different functionality:

      Emergency lighting units in the BASIC family make manual tests possible. The duration of the emergency lighting function must be checked manually. The required test log must be maintained manually. The test is performed either using the optionally installed test switch on the emergency luminaire or using a switch in the electrical installation.

      Emergency lighting units in the SELFTEST family perform both the function as well as the duration test according to a defined pattern. Any manual intervention is not necessary for this. It can be established using the indicator LED whether the test was successful. The required test log must be maintained manually.

      Emergency lighting units in the PRO family have a DALI interface. The emergency lighting unit communicates with a control unit via this interface. Using the control unit, the entire emergency lighting system can be controlled and monitored from a central point. The test log is created automatically and stored on an external data carrier if necessary.

  2. What is EBLF?
    • EBLF stands for “Emergency Ballast Lumen Factor” and is the ratio of the lamp luminous flux in emergency lighting operation to the luminous flux of the same lamp during operation with the corresponding reference ballast.
      The value of the EBLF must be stated in the data sheet. Thereby, the smallest value between 60 seconds after mains power failure and the end of the rated operating time must be stated. The value after five seconds must reach at least 50 % of the stated EBLF. See EN 61347-2-7 for the precise wording of the standard requirement.

  3. Is the dielectric strength test with 1500 V AC permitted to be used for emergency luminaires?
    • In order to avoid any damage of the electronic control gear elements, the dielectric strength test with VAC is not permitted to be used.
      According to IEC 60598-1 Annex Q and ENEC 303 Annex A, every delivered luminaire should be subjected to an insulation test (insulation resistance measurement) with 500 VDC for the duration of one second. The test voltage is applied between the phase and neutral conductor terminals connected to each other and the earth conductor connection terminal. The insulation resistance must be at least 2 MΩ.

  4. What is REST mode?
    • Emergency operation is automatically started when the mains supply is switched off. If the Rest mode is activated, the discharging of the battery will be minimized by switching off the LED output.
      Rest mode can be used during short periods of time when a building is completely unoccupied and the mains supply is switched off intentionally, for example during a holiday period. Using Rest mode prevents a full discharge and possible damages to the batteries during these times.
      Activation is only possible after the mains supply has been switched off.
      A detailed description of the REST mode can be found in the product manual of the respective product.

  5. What is the INHIBIT mode?
    • If the INHIBIT mode has been activated before switching off mains, instead of going into emergency mode the driver will automatically activate REST mode.
      A detailed description of the INHIBIT mode can be found in the product manual of the respective product.

  6. What is the Prolong time?
    • The Prolong Time allows the EM driver to continue emergency operation after restoration of the power supply.
      The device leaves this continued emergency operation after the set time has expired or as soon as the low voltage battery cut off level has been reached (discharge protection), that is, when the total operating time has been exceeded.

  7. How does the simple corridor function work?
    • The simple corridor function is an easy way to realise a simplified corridorFUNCTION with the use of a standard presence detector.
      When presence is detected the device switches to 100 %. When no presence is detected anymore the device switches to 10 %. A detailed description of how to use the simple corridor function can be found in the datasheet of the respective products.