Light fixture disassembly?

[vavet]

I have two 4 foot twin tube fixtures not working. I’ve exchanged the tubes other light fixtures and they worked. I’ve taken known good tubes and installed the, in these 2 fixtures and they did not work.

So I suspect the wiring. Perhaps a wire nut came loose.
I can’t figure out how to disassemble the cover on the fixture to inspect what’s inside. Anyone have any advice?

 

[Fishingfoolemjak]

See that little metal clip at one end on the face? Turn it 90* and the cover will come off....

 

[Mr_fixit]

That won't be a loose wire, It's the poor quality ballast that's made in China. Of course, that's my opinion.

 

[Platonic Solid]

To be fair - most name brand quality ballasts come from China too. Even the best ballast has a life span.

 

[tfi racing]

This is some kind of joke,right? We all had a laugh-now just go fix your light...

 

[vavet]

Thanks, that was it. It just took more force than I expected to turn the clip and I chickened out thinking I was going to break it.
These fixtures are about 4 months old. 2 of 10 are not working.
It seems like it must be the ballast. The wires are connected on the first one. I haven’t disassembled the second unit yet.
Now the question is: do I replace the ballast? Or change the tube to one that doesnt require the ballast? What I have now are LED tubes, but the label clearly indicates the ballast is required.

 

[Platonic Solid]

Since a quality ballast will cost as much as 2 LED bypass lamps, this is a no brainer.

 

[EOC_Jason]

Check the wires going into the ends of the connectors, not just the power connected to the ballasts... When I install them I always give them a good push-in and then a little tug to make sure they are secure. I've come across more than one that wasn't inserted all the way or wasn't a tight connection.

But yes, ballasts do fail too...

 

[Bert_]

I think those drop in tubes have a tendency to shorten the life of, if not kill ballasts.

 

[OH_Varmntr]

This is some kind of joke,right? We all had a laugh-now just go fix your light...

Don’t forget there are folks from all levels of experience on here. [emoji482]

 

[cybrdyke]

Thanks, that was it. It just took more force than I expected to turn the clip and I chickened out thinking I was going to break it.
These fixtures are about 4 months old. 2 of 10 are not working.
It seems like it must be the ballast. The wires are connected on the first one. I haven’t disassembled the second unit yet.
Now the question is: do I replace the ballast? Or change the tube to one that doesnt require the ballast? What I have now are LED tubes, but the label clearly indicates the ballast is required.

Being that new, two ballasts shouldn't be dead unless their really really crappy ones. Before you decide if you want to replace the ballast, you should verify which ballasts your lamps are compatible with. If that turns out to be difficult, then just get yourself some bypass tubes.

I think those drop in tubes have a tendency to shorten the life of, if not kill ballasts.

Nope.

CD

 

[Bert_]

Nope.

CD

Any experiences to back that up?

I have seen quite a few early ballast failures show up shortly after installing those drop in tubes. In one building there was a strange symptom, half a dozen lights would work one day, next day they would not light, then a day or two after they would be fine again. That cycle repeated itself for a couple of weeks. I have never seen that happen with the fluorescent lamps that the ballasts were intended to drive.

Now I have no idea if these ballast were already close to eol. but it just seems like to many for it to be coincidence. That said there are many more that are still working fine.

 

[vavet]

Since a quality ballast will cost as much as 2 LED bypass lamps, this is a no brainer.

If a quality ballast is as much as 2 bypass lights, then doesn’t it make it a wash from a price perspective? These are twin tube fixtures.

 

[cybrdyke]

Any experiences to back that up?

I have seen quite a few early ballast failures show up shortly after installing those drop in tubes. In one building there was a strange symptom, half a dozen lights would work one day, next day they would not light, then a day or two after they would be fine again. That cycle repeated itself for a couple of weeks. I have never seen that happen with the fluorescent lamps that the ballasts were intended to drive.

Now I have no idea if these ballast were already close to eol. but it just seems like to many for it to be coincidence. That said there are many more that are still working fine.

You've got it figured out. The LED tubes will expose a ballast that's at end of life. The driver inside the LED tube is far less tolerant of a poor current level from the ballast than a fluorescent lamp is. However, the LED tube didn't create the problem. In fact, the LED tube will actually extend the ballast life by reducing load on the transformer and thus allowing it to run much cooler.
But, yeah...if the ballast is near end of life, the tubes will misbehave.
(all above assuming that the ballast/tube are compatible)
CD

 

[Platonic Solid]

If a quality ballast is as much as 2 bypass lights, then doesn’t it make it a wash from a price perspective? These are twin tube fixtures.

From price perspective yes. From lamp life, energy efficiency and full output at cold start perspective LED bypass is superior.

Caveat - There are fluorescent lamp and ballast combinations that will yield very long lamp life and energey efficiency, but the price for this premium lamp/ballast combination is higher than their LED bypass equivalents.

 

[cybrdyke]

From price perspective yes. From lamp life, energy efficiency and full output at cold start perspective LED bypass is superior.
/QUOTE]

Nope.
The large majority of both styles of tubes are rated at 50,000 hours with some up to 70,000 hours.
Both bypass tubes and plug and play tubes vary between 110 and 130 lumen per watt. For instance, the Lumegen 22w bypass tube delivers 2640 lumens (120 lpw). The Philips 16.5w InstantFit uses 20 watts, ballast losses included, and delivers 2500 lumens (125 lpw).
Most of both types are rated down to -4F, and will come to full brightness at start up even when cold.
Now, one might be able to find an exception, but for the most part, the only difference between both systems is whether or not you want to leave the ballast in.
CD

 

[Platonic Solid]

CD - I was comparing Fluorescent vs LED, not bypass vs ballast compatible. My bad.

That said, WRT ballast compatible vs bypass - If you're capable of wiring a fixture, there's no good reason to use ballast compatible.