LED tubes

Dec 06, 2018 Last reply: 7 years ago 44 Replies

The problem is often the light fitting itself and not necessarily the components you fit into it.

If you fit any of any kind of bulb in a recessed downlighter fitting then expect it to get hot as there is often insufficient free air ventilation. Replace your fitting for something well designed for LEDs then you stand a better chance of obtaining long life.

The OP is looking for replacement tubes and they are more likely to run cool in tat kind of fitting.

Some designs of LED light power supplies do take heat into consideration by monitoring the temperature and reducing the current to the LED when it starts getting too hot. This also will reduce the light output. Unfortunately it is virtually impossible to tell what kind of power conditioning has been used in most LED lights without stripping it down (and probably destroying it)

The answer in my case (converting existing basic florries) would be to rip out the ballasts etc and replace them with proper LED drivers. Keeping that part clear of the LEDs themselves. If such a kit of drivers and tubes existed.

Yes they do, and likewise the components used in the power supplies.

The quoted Life expectancy of LEDs IF they are kept at a temperature of 25C

Those used for (domestic) floodlights are usually firmly bolted to the metal case which acts as a large heatsink.

Dave Plowman (News) used his keyboard to write :

If you already have the fitting and the tube, there is no good reason to replace them with LED. Maybe swap a magnetic ballast for an electronic version, to improve the tube life and the efficiency.

You're probably right. It was originally T12 tubes, and the later smaller ones don't work as well. And take a while to get to full brightness.

You could believe in quoted life for filament and fluorescent, but semiconductors have completely random lives and are susceptible to voltage spikes. Users are now punters.

Totally Agree. The concept of "converting" a fitting seems wrong. Rip the guts out and rewire it!

Was the quoted life for something that was left permanently on or for a device switched on/off at regular intervals? I suspect the former.

The second hand fluorescent fitting that I installed in my loft space

35+ years ago was still working yesterday - but it's probably only been switched on a couple of hundred hours during that time :)

How many of your traditional light bulbs failed at the point of switch on rather than having a gradual end of life? There was a random nature to the failure associated with traditional filament bulbs due to point in the voltage waveform at which the switching occurred and as a result of voltage spikes.

With fluorescent the light intensity fell away but probably it wasn't noticed until the tubes were replaced and suddenly everything got much brighter. I also found that the small diameter tubes not only pulsed at times but the ends became blackened relatively quickly.

While its true that many of the early LED bulbs had a poor reputation for early life failure in my experience the LEDs I've purchased in the past couple of years have proved to be reliable. However I have replaced many old light fittings with LED panel type fittings.

It can make more sense to use led strips instead of fake florrie tubes.

50k hrs for LED lighting is very optimistic. With CFLs the figure they played games with was watt equivalence, with LEDs it's life expectancy. Some LED lights don't even give any meaningful life expectancy figure now.

NT

I suspect the switch on failure mode was one of the sudden expansion of the filament, rather than a result of the spike. Expansion stress due to sudden temperature rise.

I have had mostly LED's in use here, for all of the regular in use lamps, for three years. I have not had one single LED fail so far.

A local friend attempting to swap over to LED use, has had all of his fail.

That's just an annoyance with a cost involved where it is possible to replace the bulb, but it seems to me that more and more light fittings are being supplied with an integral LED, which is *not* replaceable. If those fail, you are into much more than just an annoyance.

They are replaceable but not by an unskilled person.

Why? The fitting is standard, so any conversion LED tube can be easily replace when it will invariably fail.

The alternative is to replace two fittings in the same period of time.

Unless you can get replacement pcb/modules which fit, repairing is probably a lot more trouble than it is worth except for an unusual light fitting. It is not necessarily the LED itself which has failed.

I have a dead LED bulb on the desk in front of me, only a couple of months old. All I need to do is remember who I bought it from...

Andy

I don't believe the LEDs themselves produce any significant heat. Any significant illumination involves a number of separate LEDs, mounted on a heat sink. The associated electronics is mounted on a separate heat sink and that is the bit that gets slightly warm.

I have a 100W LED floodlight, totally enclosed, water proof and dust proof, there is no noticeable heat on the outside of the case.

The higher wattage LEDs like with car headlights and floodlights certainly do.

Any

Not anymore.

mounted on

That's the incandescent equivalent wattage.

totally enclosed, water proof and dust

Now try that with a LED floodlight which takes 100W of electricity.

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