Frequently Asked Questions About Converting Fluorescent Fixtures to LED

"Can I use LED tubes in a fluorescent fixture?" That's where most people start when they're thinking of converting to LED. Good news: the answer is yes, absolutely!

Below we cover the other common questions we get as people look into how they can cut energy costs and eliminate the need to replace failing bulbs every few years. (LED tubes last up to four times longer than fluorescents—more good news, right?)

Questions Covered:

Is there a benefit to choosing retrofit LED tubes over ballast compatible?
I have a T12 fixture. Do I have to buy T12 LED tubes?
My 8-foot fluorescent fixtures are more than 20 years old. Can I use LED tubes with them?
Do installation instructions come with your LED tubes?
If I'm doing a retrofit, do I need to buy anything besides the LED tubes?
What if I have other questions or run into problems converting my fluorescent fixtures to LED?



Fluorescent Fixture - Before Fluorescent Fixture with LED Tubes - After

Q1: Is there a benefit to choosing retrofit LED tubes over ballast compatible?

I like the idea of being able to just switch out the tubes without having to do any wiring, but there must be a reason there are so many retrofit tubes on the market.

Most people switch from fluorescent to LED to save energy. When you do a retrofit (also called a "ballast bypass,") you essentially get rid of the ballast in the fluorescent fixture. When you use ballast-compatible tubes instead, you keep the ballast. The thing about ballasts, though, is that they use energy—about 25% additional energy than a ballast-free fixture, and that energy takes away from the power going to the tube, so you don't get the full brightness. (We tested this in house, with a 2200 lumen ballast compatible tube and a 2200 retrofit tube, and the difference was noticeable.) Some ballasts also produce a massive voltage surge when you flip the light switch, in order to get the fluorescent tube started. This surge can damage, or even kill, an LED tube.

Additionally, all ballasts will fail over time, and when they do, you'll have to climb back up into your fixtures, remove all your ballast-compatible LED tubes, cut the power to the dead ballasts, install a new ballast, and put all your tubes back up.

So, if you just want a fast, hassle-free install, ballast-compatible tubes meet that short-term goal—but they do it at the expense of long-term energy costs and brightness, and you'll still need to replace your ballasts as they start to fail. If you're in the eastern half of the United States and have any questions as you research your purchase, you may well end up talking to Rob here at ELEDLights. If you ask him about ballast compatible versus retrofit LED tubes, he'll tell you, "Don't put a band aid on a broken arm." If you're going to convert to LED, do it right the first time and save yourself hassle down the road.

If you want to get the biggest energy savings for your buck and not have to worry about getting up into your lights again for many years, retrofit LED ballast-bypass tubes are the way to go. 

Q2: I have a T12 fixture. Do I have to buy T12 LED tubes?

Our T8 LED tubes fit both T12 and T8 fluorescent fixtures. (If you are switching from T12 fluorescent to T8 LED tubes, the energy savings you experience will be even more noticeably, by the way. Those fat T12 fluorescent tubes are even less efficient than the T8 fluorescents.)

Even more good news for you: if you have a fluorescent fixture designed for T12 tubes, you don't need to change out the tombstone when you convert to LED. (If you have T8 tubes, see If I'm doing a retrofit, do I need to buy anything besides the LED tubes? for more information on that.)

Q3: My 8-foot fluorescent fixtures are more than 20 years old. Can I use LED tubes with them? 

If they're still in good condition and you're not itching to install sleek new integrated LED linear fixtures—absolutely.

The simplest option is to retrofit the fixture so that you can use any 8 foot LED tube with it—and 8 foot tubes are actually the easiest to retrofit. Simply disconnect the wires running into and out of the ballast and connect them together, hot to hot and neutral to neutral.

Alternately, you may be able to put in a "plug in play" ballast-compatible 8-foot tube, which saves you the trouble of wiring. The downside is that you have to make sure to get one that works with the ballast in your fixture. If you don't know what kind of ballast the fixture has, that can be difficult. Also, ballast compatible tubes, as mentioned in "Is there a benefit to choosing retrofit LED tubes over ballast compatible?", lose efficiency due to the power consumption of the ballast—and you're eventually going to have to replace the ballasts as they fail. ELEDLIghts.com recommends retrofit, ballast-bypass 8ft LED tubes instead for those very reasons.

Q4: Do installation instructions come with your LED tubes?

You bet. Most of our tube product pages have a short video tutorial, plus you'll find a link to installation instructions (PDF format) with clear wiring diagrams in the specifications section on each tube product page.

Q5: If I'm doing a retrofit, do I need to buy anything besides the LED tubes, or are there other parts I'm going to need to upgrade my fluorescent fixture?

8 foot tubes require nothing but the tubes, unless the tombstones in your fixture are cracked or broken, in which case you purchase new ones pretty inexpensively when you place your tubes order.

Also, if you're replacing T12 tubes, you won't need to change any tombstones; they'll work just fine for the retrofit.

If you're replacing 4ft T8 fluorescent tubes, you'll need to do a little more hands-on research to find out whether the tombstones in your fixture are "shunted" or "non-shunted."

4 foot LED tubes require one-side power, which means that when you bypass the ballast, you'll do all the wiring into one—not two—tombstones. For that, you need non-shunted tombstones. Here are two ways you check which your fixture has:
  1. Visual examination: If the tombstone has two differently colored wires coming out of it (one black, one white, for instance), it's very likely non-shunted. A non-shunted tombstone has 2 inlets for wires: the hot wire goes in one inlet and the neutral goes in another. With shunted tombstones, there is only one inlet and one wire.
  2. Voltage meter: Turn the meter to Ohms, then insert both prongs into the tombstone, as if they were a tube. If the meter lights up or beeps, the tombstone is likely shunted. If it does not, it is likely non-shunted.
If you have shunted tombstones on your 4 foot fixtures, you'll need to order one new tombstone for each of your new LED tubes. You'll find them in the accessories section on any 4 foot LED tube product page on our site.

Q6: What if I have other questions or run into problems converting my fluorescent fixtures to LED?

We have years of experience with all kinds of fluorescent tube fixtures—call, live chat, or email us for help: 215.355.7200 or lights@eledlights.com!