A Type A LED tube plugs into the fixture’s existing ballast, as long as that ballast is on the tube maker’s compatibility list. A Type B tube needs the ballast taken out and the fixture rewired, a job for an electrician, and a Type AB tube works either way.
The three kinds
| Type | Power comes | Who fits it |
|---|---|---|
| A, plug and play | Through the fixture’s ballast | You, once the ballast is confirmed on the tube maker’s list |
| B, ballast bypass | Straight to the sockets, ballast removed | An electrician |
| AB, hybrid | Through a compatible ballast, or direct after a bypass | You on the ballast; an electrician for the bypass |
From Feit’s ballast compatibility page and tube guides.
Before you choose a Type A tube
A Type A tube relies on the ballast to work, so the ballast has to suit the tube. The makers’ lists go by the ballast’s exact model, printed on its own label inside the fixture cover. The fixture’s wiring sits under that cover too, so have an electrician read the model for you.
- Feit keeps a ballast compatibility list for its Type A tubes, and says a ballast in a fixture more than 20 years old may be near the end of its life and can fail when a new lamp goes in.
- LEDVANCE’s list for its Sylvania tubes asks you to match the ballast maker’s exact description, recommends testing a few fixtures first, and says the tubes aren’t for ballasts more than ten years old.
- Philips says its LEDtube Type A T8 (046677580230) works with most instant-start electronic ballasts, and links its own compatibility list.
The makers set different ballast ages, so go by what the maker of the tube you’re fitting says.
Type B and AB tubes
A Type B tube runs on line voltage wired directly to the sockets, with the ballast taken out. That’s rewiring the fixture, so have an electrician do it. Westinghouse’s linear LED lamps in its 2022 catalog are this kind.
A Type AB tube, such as Feit’s T4815/4CCTABLED/2CAN, runs on a compatible ballast for now and on direct wiring once the ballast is bypassed. If the ballast fails later, an electrician can bypass it and the same tube carries on.
After a bypass
Feit’s bypass instructions finish with a retrofit label on the fixture, so anyone changing a tube later knows the ballast is gone, and from then on it takes only Type B or Type AB tubes. Look for that label before you change a tube, because a fluorescent or Type A tube needs a ballast and a bypassed fixture no longer has one.
If there’s no label and you can’t tell whether the ballast has been bypassed, have an electrician check before you fit a tube.
Some 4 ft. LED tubes
| Tube | Watts | Lumens | Hours |
|---|---|---|---|
| Feit T48/840/LED/2, Type A, for T8 or T12 | 14 | 1,750 | 50,000 |
| Feit T4815/4CCTABLED/2CAN, Type AB, T8 | 18 | 1,800 | 50,000 |
| Philips 16T8/LED/48-840/IF18/G, Type A, 47-1/4" | 16 | 1,800 | 36,000 |
From the makers’ product pages. Feit sells its T4815 as a T8 replacement on a ballast, and for T8 or T12 fixtures once they’re bypassed.
Match the length and the two-pin G13 ends to the old tube, and check that the LED tube’s listing names your fixture’s tube size.
The old fluorescent tube contains mercury. If one breaks, follow the EPA’s steps on the broken CFL cleanup page.
Switch the power off at the breaker before you change a tube, and leave anything under the fixture’s cover to an electrician.
Another shape?
Bases and shapes