LED tubes in ballasted fluorescent tube fixture.....

Did not see this addressed here before and realize that there may be several sources outside of Permies for the answer....but thought the answer may be of use to other members so here goes.   Had the fluorescent tube over the stove go out and was considering replacing the starter to see if that was the problem.  But before doing that, I remembered that I was interested in just replacing fluorescent tubes like this with LED counterparts.  There are several LEDs with the same pin configuration, tube length, and in a range of temperature 'colors'.   My question being, is there any modification needed of the lamp/receptacle for an LED tube to replace a fluorescent tube.  Certainly it seems the ballasts can be bypassed, but do they NEED to be.  And what of the starter module that I just removed from the unit.  Would it be superfluous as well?  I'm talking about a 24" T-12 F20 tube here so something pretty standard.  Thanks!

I tried some LED replacement tubes in some older shop fixtures and they didn't work properly.  It turns out you need newer electronic ballasts for this to work as plug-and-play for most of them (or LEDs that don't use a ballast at all, in which case you have to rewire the fixtures).

I have wrestled with this in various old and new fluorescent fixtures. Compatibility is very hit or miss. I haven't found a clear line between the old transformer ballasts and the newer electronic ones.

I also worry, in general, about the loss of efficiency that comes with converting voltage up and down for no reason except backwards compatibility.

So, for high-use fixtures, I really lean toward replacing the fixture entirely. For occasional use fixtures, I pick up lower-wattage fluorescent tubes on clearance.

This is a super simple conversion. I've done several. You'll just need to cut the ballast out of the fixture and connect one end of the fixture to hot and the other to neutral.
Disclaimer: I'm not an electrician; don't touch things that go *zap* when you touch them.

This guy gives a great tutorial:


Good luck!

John Weiland wrote: My question being, is there any modification needed of the lamp/receptacle for an LED tube to replace a fluorescent tube.

If the LED tube is labelled as a direct replacement, do not make any modifications. They are designed to just plug in to the existing fixture, in theory. But keep the receipt just in case.

Thanks for these helpful and informative responses.  I'm pasting a link which may be helpful for others as well that describes the difference between some of the LED tubes you may run into at the local retailer:

https://www.penglight.com/4-types-of-led-tubes-type-a-type-b-type-c-and-type-ab/

Based on this thread, I'm inclined to either solve the ballast problem and stick with a fluorescent tube or, if the price is reasonable, go with a plug-n-play LED tube made for a legacy ballasted system.  It now makes sense to me why the few self-contained, turnkey LED tube fixtures that I've purchased in the recent past had 'innards' that looked rather different than a standard fluorescent tube set-up.   Again, thanks for great insights here.

Personally I have been looking at the low voltage bulb replacements.  If it is done correctly I should end up with a bulb that can be lite from either AC or low voltage DC.  At the switch add a power supply and rectifier and a double pole switch.  Then run a low voltage line to the switch too.  Then the light can run from either battery or from AC.  The advantage is the system won't need any big inverters or feed back protetion gear for the line.  More expesive on an individual basis but should be far less expensive over all.

Why such a complex approach? Better to go full DC, I think.

I guess it depends on the setup, but mixing line AC and low voltage DC wiring in the same system seems like a pretty substantial fire hazard to me. Unless I've misunderstood what you're proposing.

UPDATE: It's not a bad idea, but personally I would leave the AC wiring intact without jury rigging it. Kitchen fires and electrical fires seem to be the most common causes of house fires, and investigators look for "cowboy wiring" and semi-permanent extension cords. I think it's much safer to have a dedicated DPST switch "downstream" of the AC/DC power supply, receiving both DC sources. As long as the circuit from the batteries has overcurrent protection (fuse etc.) matched to the wire used, it should be reasonably safe.