Why is my LED replacement for a flurescent tube not working?

[JohnW2]

The majority of people buying 'tubes' just expect them to work. They have no understanding of what may or may not be contained in the fitting or the tube, or how to dismantle light fittings and rewire the internals in the multiple ways that the various tube affairs require.

All true, but the blanket assertion you posted seemed to imply that fitting an LED tube to an existing fitting was "....guaranteed to be a pile of expensive time consuming problems." for everyone.

 

[robinbanks]

See the orange wires?

Cut them where the blue arrow is
Strip about 1cm of the orange sheathing off each end
Twist the copper strands and fold them over into a tight U shape
Remove the red scribbled wires entirely from the screw terminals
Link one orange wire onto the L and one onto the N, it doesn't matter which, per the green lines

Make sure you examine the LED tube and do not connect the "short circuit end" to the orange end

If you'd rather wire it up so the tube can go in any way round, post back. Additional materials will be required

 

[ericmark]

I have to agree in part with both @flameport and @JohnW2 the fluorescent fitting is not designed to take LED lamps, but of course neither were all the other fitting, be it E27 or BA22d the light is directed away from the base so often not in the direction wanted, and the LED tube does direct the light better into the room to the fluorescent tube it replaced, unlike many pendent fittings.

The idea of a light which has a limited life, even if that life is in years, needing the ceiling to be messed with to install yet another light fitting, and all the old fitting is dumped, makes very little sense, when the old fitting can be converted and once done, there is no wiring required for the householder to do when changing it.

The old problem is when wired like this

yes some kits do have a sticker to put on the fitting to show which way around to fit it, but wired like this

it does not matter, the

starter can be replaced with a fuse, and can't see why wire wound ballast needs removing, but shorting it out will mean less heat so it will use fewer watts per lumen as a whole if ballast shorted or removed.

With the HF ballast or electronic ballast, there is no gain using LED to fluorescent, only reason to change is the problem finding fluorescent tubes, the way they are wired, the ballast must be removed, at least from the circuit even if not physically removed, there are now a host of push in connectors

and these are the simple way to convert. The question is if the wires are long enough?

You are removing the length of the electronic ballast.

There are LED tubes designed to work with an electronic ballast, however I don't know which will work will electronic ballasts, maybe someone can help say which makes to use.

 

[JohnW2]

The idea of a light which has a limited life, even if that life is in years, needing the ceiling to be messed with to install yet another light fitting, and all the old fitting is dumped, makes very little sense, when the old fitting can be converted and once done, there is no wiring required for the householder to do when changing it.

Exactly my feelings. Even if someone needs to pay an electrician to effect the initial 'conversion', thereafter any required 'tube replacement' can be done by the householder, just as they would have done with a fluorescent tube.

I would also add (as I usually do!), that a quoted/claimed (median) life expectancy of, say, 10,000 hours does NOT preclude the possibility of it failing after 10 hours - so that 'messing up of the ceiling' could happen much sooner than one expects/hopes.

 

[ericmark]

I would also add (as I usually do!), that a quoted/claimed (median) life expectancy of, say, 10,000 hours does NOT preclude the possibility of it failing after 10 hours - so that 'messing up of the ceiling' could happen much sooner than one expects/hopes.

My first LED tube lasted just over a year, and for most of that time, the house was empty, to replace clearly no wiring required. The second one lasted until my son fitted down lights instead.

It took a day to change, time to go to Screwfix as I did not have one in stock, the time it would take to get an electrician to fit a replacement is clearly a lot longer.

 

[Fred Blogs]

Well all you knowledgeable people seem to think this is a monumental task to get these things to work. The two that I bought from B&Q just worked. I didn't have to remove anything or rewire anything I just plugged them in and they worked.

 

[JohnW2]

My first LED tube lasted just over a year, and for most of that time, the house was empty,

As I said, I think that many people do not really understand the meaning of the (median) life expectancies quoted by manufacturers, even if they are correct. For simplicity, look at this list of a very small number (11) of actual 'times to death' (in hours) of an LED tube (or anything else):

1
2
10
20
500
10,000
≥10,000
≥10,000
≥10,000
≥10,000
≥10,000

The median of those 'survival times' is 10,000 hours, even though nearly half of them (5/11) failed in 500 hours or less (some a lot less!).

to replace clearly no wiring required. ....

That's the point. Once the first one has been done, any subsequent replacements are no more difficult than replacing a fluouresecent tube.

 

[ericmark]

OK, mean mode and median is an 'A' level thing, and not everyone will understand. I look at what we can buy

the GX53 seems better 75 mm than the 50 mm lamps, but still rather small. The 2D lamp, does have a LED option, but be it 50 mm, 75 mm or 200 mm they are all made for fluorescent and the LED is an adaption.

What I want is a lamp when it fails, it can be repaired by the unskilled, and not seen a LED only lamp which fits the bill.

 

[JohnW2]

OK, mean mode and median is an 'A' level thing, and not everyone will understand.

Indeed. and understandable, which is why I tried to explain, since people seem to put a lot of weight on the published/claimed 'life expectancies' of lamps/bulbs etc. and often express surprise, disappointment or worse when a product they buy lasts dfor a much shorter time than the published/claimed 'life expectancy'.

Of the various types of 'averages' (the most common three of which you have mentioned) the median (which is what is used) is probably 'the least of the evils', the most reasonable reflection of what one can expect and certainly the most practical.

Of the three you mention, the 'mode' ("the most popular") is inappropriate for the sort of products that interest us. However, it is of value to manufacturers of selling of products which come in a range of discrete sizes/types/whatever (e.g. shoes, clothes, screws, car tyres), since it indicates which size/type one should manufacture or stock most of.

The 'median' is simply the figure (lifespan or whatever) that half of the products can be expected to achieve. So if one buys 50 products with a median expected life of 10,000 hours, then one can expect 25 of them to last for at least 10,000 hours. However, all it tells one aboutcthe other 25 is that they will last for less than 10,000 hours - but it tells us nothing about 'how much loess' Hence, as I illustrated in my previous post, it is possible to have a situation in which half survive for 10,000 hours or longer (so median is 10,000 h, but with all of the other half dying extremely early.

The other possible average to quote is the mean, which is the type of average that most people are familiar with ("add up all the numnbers and divide by the number of them"). The first problem here is a practical one, since one can only get an estimate of the mean after the very llast one has died - and that could take many years! However, a me an also has the same sort of capacity to mislead as does the median - since just a very small number of 'extremely long-lasting' products can dramatically increase the mean. Consider again a list of survival (in hours) of 11 products:

1
2
3
4
5
6
7
8
9
10
110,000

The mean of those 11 survival times is fractionally over 10,000 hours (actually 10,005), despite the fact that 10 of the 11 failed in the first 10 hours! With those numbers, the median is 6 hours - which I would suggest more reasonably reflects the actual situation than does the mean of 10,005 hours

 

[SUNRAY]

Yes but with all of the definitions considered, If I had a number of lights (let's say 9) and I fitted a new light emitting product in each of them listed as 25,000 hours, I feel that 9 is a large enough sample to expect to get 175,000 hours of service averaged across them.

Accordingly if one fails within the first hour of use I think it would be fair to expect one of the remaining 8 to last 49,999 hours, what I don't expect is for all of them (actually 10 devices) to fail well inside the first year (which is only 8,766 hours total but average daily use is probably under 2 hours or 736 hours annually) and for the next 2 full sets including spares to do the same thing.

Especially as the 3 previous technology devices had each been in there for many years (decades possibly)

 

[SUNRAY]

Shoving LED 'tubes' into places where fluorescents were intended to go is guaranteed to be a pile of expensive time consuming problems.

Possibly, but possibly nothing compared to the guaranteed pile of expensive time consuming problems caused by

Slinging the existing

servicable

fitting away and installing an LED batten in it's place.

Sadly yet again I find your generalisations at odds with my experiences.

 

[JohnW2]

Yes but with all of the definitions considered, If I had a number of lights (let's say 9) and I fitted a new light emitting product in each of them listed as 25,000 hours, I feel that 9 is a large enough sample to expect to get 175,000 hours of service averaged across them.

You could well be disappointed, then

You say you have "considered all definitions" (which I take to mean the different types of averages), but you are actually only thinking about one, namely the mean. When you go on write ....

Accordingly if one fails within the first hour of use I think it would be fair to expect one of the remaining 8 to last 49,999 hours, ...

.... you would be correct IF the 25,000 hours 'listed' were a mean. However, it's not, it is a median, and that changes everything. One simply can't do that sort of arithmetic with medians, not the least because a median is not dependent on the actual values, only on what value separates 'the lower half' from the upper half'. A median of, say, 25,000 hours does not tell one whether those who didn't survive for 25,000 hours all survived for only 1 hour or whether they all survived for 24,999 hours - the median would be 25,000 h in either case. By treating the 'listed' figures as if it were a mean (which it isn't) you are effectively assuming a totally symmetrical distribution of the figures (in which case mean and median wou[kd be the same), which is likely to be very far from the truth.

Just taking your example above, if the median were 25,000 hours, then it could be that there were none which were significantly (or at all) above 25,000, so there wouldn't be any of 49,999 hours to balance '1 hour' ones

I haven't got time at the moment but, if you so wish, I'll try to explain in more detail 'in due course'.

Kind Regards, John

 

[SUNRAY]

You could well be disappointed, then

You say you have "considered all definitions" (which I take to mean the different types of averages), but you are actually only thinking about one, namely the mean. When you go on write ....


.... you would be correct IF the 25,000 hours 'listed' were a mean. However, it's not, it is a median, and that changes everything. One simply can't do that sort of arithmetic with medians, not the least because a median is not dependent on the actual values, only on what value separates 'the lower half' from the upper half'. A median of, say, 25,000 hours does not tell one whether those who didn't survive for 25,000 hours all survived for only 1 hour or whether they all survived for 24,999 hours - the median would be 25,000 h in either case. By treating the 'listed' figures as if it were a mean (which it isn't) you are effectively assuming a totally symmetrical distribution of the figures (in which case mean and median wou[kd be the same), which is likely to be very far from the truth.

Just taking your example above, if the median were 25,000 hours, then it could be that there were none which were significantly (or at all) above 25,000, so there wouldn't be any of 49,999 hours to balance '1 hour' ones

I haven't got time at the moment but, if you so wish, I'll try to explain in more detail 'in due course'.

Kind Regards, John

Currently assisting 3rd grandchild into GCSEs so I hope I have a reasonable understanding of averages, so yes I am aware of the formats of mean, mode and median.
I'm also aware that most reasonable samples tend to come up with fairly similar results.

 

[robinbanks]

Well all you knowledgeable people seem to think this is a monumental task to get these things to work.

I wouldn't say putting two wires into a terminal block is "monumental"; it's less effort than changing a 3 pin plug

The two that I bought from B&Q just worked.

Your fitting/bulb pairing would then appear to be different from the OP's. It's wonderful that the ones you plugged in "just worked" but the ones the OP plugged in didn't, and alas your experience doesn't help them(unless you're asserting that they can definitely just go to b&q, buy the same thing you did and it will Just Work?)

 

[JohnW2]

Currently assisting 3rd grandchild into GCSEs so I hope I have a reasonable understanding of averages, so yes I am aware of the formats of mean, mode and median.

Fair enough,but, for what it's worth, In terms of such matters, I can certainly trump GCSE-level knowledge in a very big way

I'm also aware that most reasonable samples tend to come up with fairly similar results.

Yes, the larger the sample, the closer will what one sees reflect how things 'really are' in the entire population.

However, what you are overlooking is the question of "how things 'really are' in the entire population". You seem to be assuming a nice neat symmetrical distribution centered on the mean (the 'bell-shaped-curve of a 'Normal' distribution). However, with most 'survival' data, that simply is not the case.

For many manufactured products (LEDs, hard drives or whatever) as well as biological survival (e.g. human survival) the common situation is what is often called a 'bathtub-shaped' survival curve - with quite a lot of very earth 'deaths' (due to manufacturing defects, congentital abnormalities or whatever), followed by a long period during which there are hardly any failures at all, until one eventually reaches the point at which failure/death gradually starts increasing (due to 'old age'/'wearing out' . Here is a typical curve that I have just pulled fromon-line ...

... so the 'very early failures' are not any sort of 'quirk' but, rather, they are "how it is", and that will become increasingly closely reflected in what you see in a sample as the sample gets larger. In the sort of situation we are talking about (with the LEDs), the median (which is what the manufacturer quotes) will often be much higher than the mean (which is what you have assumed)). In the example I used in post #22 (which may well be the sort of thing ine sees with LEDs etc.), if one assumes that all the values in the top half were exactly, 10,000 (rather than the " ≥10,000 " I put in that list), then the median (which the manufacturer would quote) would be 10,000 hours, whereas the mean (which is what you seem to be assuming) would only be 5,503 hours.

No time at the moment, but later I'll see if I can think of a better way of explaining.