Question
Are there LED retrofits for emergency lighting? Are two light sources required?
Answer
Product category Emergency LED Drivers (FTBV) covers battery packs that can be factory- or field-installed into specific LED luminaires. These battery packs are functionally parallel to fluorescent luminaire products commonly referred to as “inverter-charger packs.” However, because certified emergency luminaires are evaluated for providing a prescribed minimum light output for at least 90 minutes in addition to risk of fire and risk of electric shock, emergency LED drivers certified under FTBV are classified for use with specific luminaires, identified by manufacturer and model number on the product or in the installation instructions provided with the product.
Most LED luminaires with battery backup (or other emergency source) use the same LED array (lamp) for normal and for emergency operation, although the light output during emergency operation may be less to preserve battery power for illumination for the required duration. However, an LED luminaire may alternatively have an auxiliary array that operates only during emergency (power outage) situations, with the emergency source feeding only that auxiliary array.
The Guide Information for Emergency Light Emitting Diode Drivers (FTBV) can be viewed on UL’s Online Certification Directory at www.ul.com/database and by entering “FTBV” in the category code search field. The Guide Information for FTBV will also appear in the 2012 UL White Book.
