Can T8 LED tube lights be used in T12 fixtures?
In answering this question, we need to evaluate for both physical as well as electrical compatibility.
In terms of physical compatibility, both T8 and T12 lamps use the same G13 bi-pin base, so as long as they are the same length (e.g. 4-ft), a T8 lamp will physically fit inside a T12 fixture.
Electrical compatibility is a bit trickier, because T12 fixtures will almost always contain a T12 ballast, which is not compatible with T8 lamps. Direct-wire compatible T8 LED tube lights can be used in a T12 fixture, as long as the T12 ballast is either bypassed, or completely removed. T8 LED lamps which are not direct-wire compatible (with ballast) will require a T8 ballast to operate, so unless the T12 ballast in the T12 fixture is replaced with a T8 ballast, a non-direct-wire compatible T8 LED lamp will not work in a T12 fixture.
Waveform Lighting's T8 LED tube lights feature compatibility with all ballast configurations (ballast, ballast bypass single ended, ballast bypass double ended), so they can safely be used in T12 fixtures as long as the T12 ballast is bypassed or removed.
For further instructions on installation and wiring, please reference our installation manual: