LED Spec Assistance-Use of External Drivers

In an attempt to provide assistance to specification writers that are tasked with identifying the most cost-effective energy efficient lighting for their commercial, industrial and federal government properties GET, LLC through our friends at Independence LED Lighting offer up advice to help those writers and readers of this blog to identify key specification areas of focus in the use of LED lighting technology. 

Our focus: external drivers.
External drivers, a key selling point of LED lighting, have multiple efficiency, smart control, operation, and life safety advantages over Internal Drivers.  It is suggested that by separating the heat created by the drivers from the LEDs on the linear “Tube” modules, the combined system runs more efficiency, maintains its color more consistently, and lasts longer. Heat is simply the enemy of the LED. 

Also external drivers provide increased flexibility over internal drivers, when it comes to maximizing future connectivity for dimming, occupancy sensors, light harvesting, alert signals, and WIFI control. Many end users are focused, in the short term, on the energy savings with LEDs but the modular advantage of an external system is the ability to improve the technology as it evolves by connecting into other smart controls.

Since the external driver is a separate module, it can be easily replaced in the same way that a fluorescent ballast is replaced upon failure without throwing out the whole tube. This is the simple model of “don’t throw the baby out with the bathwater”, since the LEDs and the tube component are more valuable than the driver component. Modularity creates operating as well as energy efficiency. Think of the driver as the starter on a car or the power supply on a computer. It is best to specify Non-Proprietary Drivers for maximum flexibility over time to purchase if necessary additional drivers.  For failure diagnostics, if a tube goes dark completely then the failure is most likely in the driver versus any of the diodes on the tube, but personnel can always easily cross check by simply connecting a failed tube to a nearby fixture. Given that the drivers are the weakest link in the LED system, request a nominal extra inventory of drivers (e.g. 1 per 100 Tube sets) to have at hand in the event of failure. This is not unlike stocking extra ballasts in a project.

Finally, fluorescent tube fixtures to date have been typically designed to bring alternating current (AC) line voltage typically at 120V to 240V into the fixture and then step it down to safer lower voltage via the fluorescent ballast to Direct Current (DC). The danger of using internal driver LED tubes is that the step down to the lower voltage occurs inside the tube. So the installer of internal drivers bypass the ballast and run the higher voltage directly into the socket “tombstones” of the fixture. This means that the dangerous line voltage is right at hand in the fixture. If personnel touch the sockets, they WILL RECEIVE A SHOCK, and they are at risk of falling back off a ladder at the 120V level breaking an arm, hitting their heads, or worse.  There is an increased likelihood of  fatality for fixtures that are powered with higher 240V with the internal drivers. By contrast, external driver LED technology mirrors the model of the original fixture design by replacing the fluorescent ballast with the external driver and stepping down the voltage as it is fed into the tubes for increased safety.  LED tube solutions should include options for external drivers that are non-proprietary  to a sole source, so that the drivers can be replaced if necessary either during or after warranty periods. 

Need an LED solution for your facility? Check out our website at www.get-guam.com or give GET, LLC a call at 671-797-0789.  We are a provider of Independence LED Lighting and Deco Lighting Inc. products-Made in America!!!