Converting Old Fluorescent fixture to LED

[ht96]

Context:
- This fixture is daisy chained and this stopped working (with new tubes / starters) a few months back. The subsequent fixtures in the chain are fine.
- I opened it up and checked with my voltage detector that the current is entering but not leaving the ballast.
- I bought an LED tube (with starter, works with my other identical fixtures ) but am looking to bypass the ballast on this one to make it work

What I'm doing:
- I'm sending the live wire to the left tombstone by shorting the grey and brown wire at where the starter was (to test)
- Using my voltage meter I can see that the current is getting to the tombstone on the left
- Tube still not lighting up

Am I doing something wrong?

 

[ht96]

Or do I just need to short the ballast? But that scares me since on the right tombstone live going in is also sent out all the way to the left tombstone so wouldn't that short live and neutral on the left tombstone gets the voltage according to the meter. Or perhaps left tombstone doesnt short them like the right

 

[ht96]

Ok, it was exactly that, but I left the LED starter in the circuit - not sure if I should bypass that too?

Any major differences in life/light?

 

[ericmark]

The tube pins are wired in series with the starter between the two ends, so just the ballast shorted out using a single block connector. Although the power only goes to one end of the LED tube, the other end is a short circuit, so unless wired in series if the tube is fitted wrong way around it is a short circuit. The replacement starter is a fuse.

 

[SFK]

If LED tube is wired like this one

2ft 9w LED Fluorescent Tube - Daylight | LEDlite (LTT29DL)

-- there is a wiring diagram link at bottom of this web page link.
I would have cut the grey wires at both ends of your fixture.
At one end of the fixture made the wires safe (ie terminated them separately and safely).
At the other end of the fixture (as per your photo) connected one grey wire to live and the other grey wire to Neutral. And earth wire to fixture.
Then put LED tube in correct end towards the end that now has power.

This means ballast and starter not used at all (saves a bit of power).

Sfk

 

[FrodoOne]

Context:
- This fixture is daisy chained and this stopped working (with new tubes / starters) a few months back. The subsequent fixtures in the chain are fine.
- I opened it up and checked with my voltage detector that the current is entering but not leaving the ballast.
- I bought an LED tube (with starter, works with my other identical fixtures ) but am looking to bypass the ballast on this one to make it work

You KNOW that the Ballast is Open-Circuit.

What I'm doing:
- I'm sending the live wire to the left tombstone by shorting the grey and brown wire at where the starter was (to test)
- Using my voltage meter I can see that the current is getting to the tombstone on the left
- Tube still not lighting up

What you are NOT doing is specifying the Make/Model/Size of LED Tube that you are using.
(Picture 1 in Post #1 gives some indication.)

The tube pins are wired in series with the starter between the two ends, so just the ballast shorted out using a single block connector. Although the power only goes to one end of the LED tube, the other end is a short circuit, so unless wired in series if the tube is fitted wrong way around it is a short circuit. The replacement starter is a fuse.

Not sure if all the above is correct.
Some LED Tube replacements (Osram SubstiTubes.) work with a working Ballast
OR
if the Ballast is Short-Circuited.
However, the "Starter" MUST be replaced with the (Supplied) 2 Amp fuse - in a case which looks like a Starter.

Some LED Tubes have the Line and Neutral connected at the "Tombstone" connector at one end and others work as a direct replacement.

More information concerning that which you are attempting to use is needed.

 

[ericmark]

I will admit when I fitted a LED tube instead of the fluorescent it was some 4 years ago and things have moved on. When I did it they would only work with wire wound ballast or with ballast removed, today there are versions that will work with electronic ballasts. So yes

Some LED Tubes have the Line and Neutral connected at the "Tombstone" connector at one end and others work as a direct replacement.

That is a good point, one does need to read the instructions with the tube. The early tubes would work with or without the wire wound ballast, and clearly since ballast is faulty, in this case want it to work without.
So in my case this

became this

with starter replaced with fuse. This

will work, however the supply end needs a label and putting the tube in wrong way around is a direct short, so not recommended to do it that way. But do need to read instructions with the tube.

 

[FrodoOne]

I will admit when I fitted a LED tube instead of the fluorescent it was some 4 years ago and things have moved on. When I did it they would only work with wire wound ballast or with ballast removed, today there are versions that will work with electronic ballasts. So yes

That is a good point, one does need to read the instructions with the tube. The early tubes would work with or without the wire wound ballast, and clearly since ballast is faulty, in this case want it to work without.
So in my case this View attachment 337151 became this View attachment 337154with starter replaced with fuse. This View attachment 337156 will work, however the supply end needs a label and putting the tube in wrong way around is a direct short, so not recommended to do it that way. But do need to read instructions with the tube.

Thank you for your comments.
As you may glean from my Post #6,
it is more than "Irritating" when those who ask questions do not specify the Make/Model/Number of any Device concerned - so that others can look-up the information which the "questioner" should have on-hand.

 

[ht96]

Apologies @FrodoOne , this is my first post. I don't think the LAP tube had any diagrams to help me, but ultimately this was what worked for me:

but this is what I tried first which didn't work:

(I had two unterminated wires at the other end, maybe I needed to remove them/short).

Perhaps this is something to do with single-ended vs double-ended tubes. This is a "retro-fit" compatible tube so I assume it needs to support a ballast in the mix hence it is only supporting diagram 1 which would support a ballast in the mix.

It is good to know that the LED starter is the fuse I needed, so happy I left it in, and that the circuit is safe.