History of the LED Tube

Millions of LED tubes have been installed in the US since their introduction about 5 years ago. Yet the LED tube has undergone many changes throughout that relatively short period of time and surely we can count on more changes ahead.

As we take a look at the history of the LED tube, we find that the common theme with each ‘type’ of LED tube is that each has their own benefit and none are flawless. Thus it has been up to the user to do the legwork in determining what is best for their particular situation.

Type A LED Tubes

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Type A LED tubes, also known as ballast compatible LED tubes, hit the market first with the promise that all you had to do was simply take out your fluorescent and install them and you have LED! In many instances it didn’t take long for both commercial and residential end users to learn that couldn’t be further from the truth.

Type A LED tubes sprouted up at Big Box stores around the country and eager customers found that the success rate of these lamps on their existing residential ballasts was minimal. On the commercial side, the three biggest lighting distributors came out and pushed Type A LED T8 lamps, and even these commercial grade Type A LED tubes had a less than stellar compatibility rate with existing ballasts. Customers received their Type A LED tubes and were disappointed to find that they didn’t work at all. Or they worked initially and then the ballast burnt out weeks/months later and they thought the lamp was defective. In actuality the ballast went bad and a new ballast had to be installed. So the upfront savings on labor that Type A customers yearned for turned out to be a mirage as it just created more work down the line. Saying that, Type A can make sense in the following applications:

  • When you have a high efficient electronic fluorescent ballasts that are relatively new (3 years or less)
  • When the long-term future of the space is unknown, and you desire energy savings
  • When budget is a concern and you want minimal upfront costs
  • When lights are tied in on the same circuit with other devices like printers. The ballast regulates the LED lamp when those devices are in operation.

Single-End Wired Type B LED Tubes

ballast-bypass-type-b-led-t8

It didn’t take long for lighting manufacturers to read the writing on the wall and realize another solution was needed. The ballast was a complication in the LED retrofit process and needed to be taken out. Thus Type B LED tubes were born.

Type B LED tubes, also known as ballast bypass or direct wire LED tubes, were released into the market initially as a double-end wired option, but then transitioned to a single end solution due to UL issues. The single-end wired Type B LED tubes quickly surpassed the popularity of Type A LED tubes. A little more work was involved in this retrofit process. The ballast was bypassed, and if the current fluorescent fixture had shunted sockets (most common in T8 fluorescent fixtures) it needed to be re-wired to one end with a new non-shunted socket. With the Type B tubes, the end user is also given a sticker to put on the fixture signifying that the fixture was modified and going forward would need a single-end wired LED T8.

The “Big 3” lighting manufacturers stayed away from this option initially due to safety concerns, such as shock during install if the power is not cut from the fixture during the re-wire process. They were also worried that upon retrofitting a fixture to Type B, an installer years later on might not read the sticker and throw in a fluorescent or ballast compatible LED T8. This would result in the lamps burning out instantly and possibly “exploding”. The risks notwithstanding, small to medium sized lighting manufacturers got behind this option and users loved it. The “Big 3” lighting manufacturers lost a lot of business over the years because of their initial decision and now they all have a Type B option. The Type B solution is the leading method for retrofitting tubes to LED by a wide margin primarily because once you have the fixture converted, all you need for that fixture to work are good LED Type B tubes (no ballast or external driver).

Type C LED Tubes

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Around the same time that Type B LED Tubes came out, GE developed a third option, Type C LED tubes. These also required bypassing the ballast but instead of wiring direct, they went a safer route by having the LED tubes hook up to an LED driver. So the wiring process essentially was like the Type A LED tubes but with a new LED driver powering the tubes instead of a fluorescent ballast.

This method was the most efficient in terms of lumens per watt and also allowed for more controls, like 0-10V dimming. But it never took off in popularity like Type B LED tubes did. The reason for this quite simply could be attributed to the cost of this operation. The tubes themselves were more expensive than Type A and Type B, and on top of that an LED driver was needed for each fixture. Install time was also comparable to Type B because the ballast had to be bypassed and a new LED driver was installed. That said, as time goes on this is one method to watch, as LED prices drop and demands for controls increase.

New Developments in LED Tubes

As with any new technology there are always improvements and LED tubes in Type A, B, and C are no different. Given the popularity, lighting manufacturers have been working on the issues of these options to come out with two new solutions that could very likely be the future of LED tubes.

Double-End Wired Type B LED Tubes

As mentioned earlier, many Type B tubes started as double end wired, but due to UL issues they were transitioned to single end. Double-End Type B LED tubes can now be produced without the UL issues, so they are taking off in popularity. The idea is that these will jump into the robust Type B LED T8 market and deliver a solution that results in less up-front work as you can re-use the existing sockets and don’t have to rewire the fixture. However, old fluorescent sockets often need to be replaced anyways making the single end option as feasible as the double end.

Type D LED Tubes

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Finally we come to Type D LED tubes, the most recent method for converting fluorescent to LED. Also known as combo LED tubes, these combine the technology between Type A and Type B LED tubes, meaning they work on the ballast initially and then when the ballast dies off, the user can bypass the ballast and wire it direct. This gives you the low up-front install cost that Type A offers, and the maintenance savings Type B offers when (if) you bypass the ballast. Initially the Type D options all came with Type A capabilities and then either single end or double end Type B capabilities. Now there are options that work off the ballast and can be wired single or double end.

This solution can bring the best of both Type A and Type B to the user, but some issues can still arise. First of all the same issues with Type A can occur, as users install Type D and find out they don’t work on their ballasts. If this is the case you can either buy a new ballast or wire the fixture to Type B. This is nice for flexibility, but going this route will be difficult to keep track of long term. Some fixtures will be wired Type A and some as Type B, so unless good records are kept there could be some confusion in the future.

What other advancements await the future of the LED tube? Despite the increase in LED prevalence, 80%+ of linear tubes are still fluorescent. Expect more changes on the horizon as the technology changes and user demands alter the landscape.

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One Response to “History of the LED Tube”

  1. Matt WrightSeptember 14, 2018 at 3:23 pm #

    Great read,Thank you

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