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what is the difference Type A,B,C led tube lights?

About LED products knowledge and info


Type A Lamps are a fluorescent ballast compatible lamp with exceptions. These exceptions are expansive, in fact almost every manufacturer suggests consulting their list of compatibilities before installing LED T8 tubes. We have found that there are even scenarios where the LED lamp product is not compatible with ballasts from the same manufacturer.

The benefits of this type are that they come in different wattages and beam angles, and lumen output for this type can be controlled by the existing ballast: Low Power (LP), Normal Power (NP), and High Power (HP). Most often, these lamps are installed as a simple “relamp” project, but it is important to consider the age of your ballasts when choosing this type. If you intend to change ballasts the week after you install these LED lamps, that may undermine the goals and objectives of your project. Whether or not type A is going to be the best solution for your project depends greatly on your maintenance story.


Type B lamps are a direct wire lamp, the most dangerous of the three. This lamp requires the ballast to be removed and the sockets wired direct to line voltage. This system will also require an un-shunted socket, where terminals on the ballast are wired independently. Even though the fixtures are to be marked as having a direct wired lamp, the potential for an LED ballast or LED driver type lamp being installed is great. This will cause severe problems including lamp failure, sparking, even fires. Because you eliminate the need for a ballast, these lamps are chosen when trying to maximize maintenance savings, but safety must be part of the overall consideration to choose a lamp of this type.


Type C Lamps are an LED lamp with a fixture mounted driver, the drivers are now available with three different standard outputs as well as programmable for more or less output depending on the light levels required. The Type C lamp is also similar to an LED fixture, as you have a light engine and a separate driver. These lamps aren’t considered nearly as often as they should be. They typically offer the longest life, and dimming capability that the others do not. The reason they’re not chosen as often is due to their higher price point. Total Cost of Owning a lighting system should be evaluated when considering whether these are affordable for your project. The type C lamp has just recently achieved controllability using different Mili-amp Drivers. The drivers are more expensive, but in some instances the will achieve a higher lamp life rating 60,000 versus 50,000 hours.