The U.S. Department of Energy reports that 75+ percent of lighting systems installed in commercial buildings are fluorescent, with a majority of these lamps being installed in recessed troffers. As LED technology continues to come down in cost, it has become a suitable retrofit option for fluorescent luminaires. All installed electrical products should carry an appropriate electrical safety listing from an organization like UL. An issue with fluorescent-to-LED upgrades is the question of whether the fluorescent luminaire retains its original electrical safety listing after the upgrade. The authority having jurisdiction decides whether luminaire upgrades require inspection.
UL has published a guide that helps building professionals navigate, available here. LINK: http://ul.com/wp-content/uploads/2014/04/ul_LumenaireRetrofits.pdf
In a nutshell, when upgrading a linear fluorescent luminaire to LED, there are three paths forward.
- First is to replace the fluorescent luminaire with an LED luminaire. In this case, the new luminaire should already have the required safety certifications. This also offers the advantage of a purpose-built product and straightforward installation.
- Second is to install an LED retrofit kit consisting of the light source plus all electrical and optical components in a prepackaged solution. In this case, the product may be certified and marked as “Classified” by a nationally recognized testing lab. The kit’s manufacturer provides a label, which is stuck on the luminaire in a prominent location and indicates the luminaire 1) has been modified and 2) can only be used to operate the specific installed LED replacement lamp. The label info must match the installation instructions and other documentation.
- The third option is LED linear replacement lamps. While “drop in” LED lamps are available, the large majority of products require electrical modification of the luminaire–changes to the luminaire’s electrical wiring, replacing the ballast with an external driver, and/or altering the lampholders, depending on the product. When such electrical modification occurs, on-site inspection and field safety certification by a nationally recognized testing lab would be needed, imposing an additional cost to the retrofit. The luminaire should be clearly labeled that it can’t be used with the originally intended lamp(s).
The information provided is for general educational purposes only. For more information and specific requirements related to your project, consult the manufacturer, applicable AHJ and appropriate UL standards.
Craig DiLouie is an educator, journalist and marketing consultant specializing in the lighting industry.