LED type B Tubes are the best solution for replacing your inefficient T8 fluorescent tubes. There are a variety of different LED styles available on the market and it’s easy to be misled by statements made by some suppliers.
A true type B double-end power tube must pass the UL safety test for leakage and not exceed 50Uf. What this means in simple terms is when one side of the tube receives power 120 -277V the opposite end if not installed in the tombstone will have no continuity and be touch-safe.
Dual-mode tubes are known as type A+B and when installed with the ballast bypassed (double end power) these tubes will not pass the UL safety test. Type A tubes on the other hand are single-end power and as such the opposite end is simply a lamp holder with no electrical connections. Type A tubes typically require the existing tombstones to be replaced with a none shunted style and have the existing wiring reconfigured so that each tombstone has both a hot and neutral wire feeding the tube. Type A tubes due to the time and expense necessary to modify the fixture are overall more expensive than a type B tube to retrofit.
Beware of any type of magic tube that claims to work with either the ballast or without the ballast and be double end powered. It is my belief there is no UL-listed product certified in this way. Just because it works does not imply it is safe, or in fact that it has been tested and approved to install in such a way.
LED type B tubes that are UL approved for double end power are the only safe way of upgrading to high-efficiency LED lighting. Investing a little more for a product that is safe and won’t present a shock hazard for anyone removing a tube in an energized fixture is priceless.
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