LED Retrofit: What you need to know about your linear fixtures

January 8, 2020

If you haven’t switched your linear fluorescent lights to LED yet, I’m sure you’re at least thinking about it. But there are some considerations you should take into mind when choosing the right way to go about the retrofit.

Ballast vs. Driver

Your traditional fluorescent light fixtures are built with ballasts. The ballast regulates the voltage to the lamp so there is an even amount of power transmitted to the light source. If the power is too high, the lamp could fail and/or break. Ballasts are also specific to the light source.

Conversely, LED fixtures are built with drivers. The driver in the LED is specific to that fixture and is meant to do the same thing as the ballast – regulate current for even light and to keep the light from failing.

Because the construction of fluorescent lamps is different than new LEDs, there are some potential problems with retrofitting LED into the exiting ballast.

Lamp Holder Limitations

Fluorescent tubes are held into the fixture by lamp holders. Lamp holders are designed specifically for light-weight fluorescent lamps. Although there are LED lamps specifically built to retrofit into ballasts, the LED lamps are heavier. This alone increases the risk of the lamp falling off the holder and breaking. And in a high vibration environment, this is especially risky.

Arcing is another risk with lamp holders. Lamp holders can get brittle after time and can break as they get older. The lamp holders can’t hold the lamps as effectively when they are brittle and will crack with age. Putting new lamps in bad lamp holder leads to a bad connection between the tube and lamp holder which would lead to arcing.


Fluorescent fixtures aren’t designed to dissipate heat. Similarly, fluorescent enclosers aren’t designed to regulate the heat that LEDs emit. If you are trying to install an LED in a traditional fixture, the LED lamps will create more heat, will have a much shorter life, and therefore will require more frequent replacements due to lamp failure or breakage.


While there are specific LED lamps built to retrofit into a fluorescent ballast, you should consider the condition of the ballast. How old is it? Most warranties for fluorescent ballast fixtures were only 1-3 years. Your fixture has likely been installed at least that long, so it is likely out of warranty. Furthermore, the ballast would not last nearly long enough to support your new LED’s lamp life.


Whichever linear lamp replacement you are looking into, studies have shown that LED replacements have a wide range of performance outputs. While improved energy efficiency was noted across the board, luminous output from the replacement LEDs wasn’t as high as the fluorescent lamp. Additionally, light distribution in the LED lamps is different from fluorescent lamps. Therefore, if the fluorescent fixture was initially installed to meet specific lighting requirements, the distribution of light from the LED replacement may not meet those initial requirements and could also cause glare or insufficient light for the application or workspace.

UL Listing

If you are considering a retrofit on a fixture that was built with an approved UL safety listing, you will want to make sure that the retrofit kit you are replacing it with carries the proper certification in order to maintain the integrity of the original UL listing. For example, to maintain the integrity of a UL1598A rating, the retrofit must be UL1598C certified.

What now?

What do we at Phoenix make of all this? Know your options. Know your environment. Is the LED replacement lamp a quick fix or does it need to last for 50,000 hours? What were the original requirements of the light? Are the risks worth the additional cost?

Because Phoenix fixtures are built for durability and used in harsh environments, we believe in safety first … and longevity second! Keeping that in mind, we recommend using either a retrofit kit or replacing the fixture completely.

Phoenix offers a simple and safe retrofit kit for snaplights. Check out this fun video to see how fast and easy it actually is: https://www.youtube.com/watch?v=2utRZggQMEE.

Without breaking your budget, Phoenix’s line of linear LED fixtures delivers the quality and durability your operations require, plus the energy savings and improved safety your company will enjoy for years to come. Check out our variety of linear fixtures.

** For more information regarding studies focused on linear LED replacement lighting, visit: https://cltc.ucdavis.edu/sites/default/files/files/publication/LED_Retrofit_Options_Linear_Fluorescent_FINAL.pdf.