I direct wired Plug and Play LEDs, is this bad?

I replaced the ballast and fluorescent tubes in a bathroom fixture with LED replacements. I'm gradually doing this to all my fluorescent fixtures as they stop working. I always buy direct wire and rewire, otherwise I'm just waiting for the ballast to fail eventually. But this is my first 18 inch, the others have all been 4 foot. And it was very hard to find an 18 inch LED tube.
The Amazon description clearly says to rewire. The instructions with the tubes clearly said to rewire. The tubes say Plug-Play and are from China. So I have rewired, though a bit confused over which was right. They turn on but are very dim, nothing like I expected. I emailed the manufacturer and to my surprise got a reply, that said they are PlugPlay and I should not rewire, and they do not work with all fixtures.
Maybe I can learn something. Will Plug and Play fail if direct wired? What is different about the circuitry, and why are some ballasts compatible and others not?
I read the Amazon reviews before buying. The negative ones were mostly from people who had not read the instructions and had not rewired.
Reply to
Tim R
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You need ^ That One! At least now.
"Plug & Play" is designed to take the strike-voltage for a fluorescent lamp. And without it, it will not light properly. Direct-Wire uses wall-plate voltage.
Save the one you have for another use.
Peter Wieck Melrose Park, PA
Reply to
Peter W.
Thanks! I've ordered the correct one and can return the wrong one.
I remain curious about the circuit but am happy with the change.
Reply to
Tim R
Standard florescent tubes have the heaters at each end, both placed in series with the supply and also the ballast/starter.
LED tubes internally are wired to the supply at one end, the other end is made as a short circuit - so that the LED tube can be used as a plug and play for a florescent tube if the starter (and ballast) is also replaced with a short.
Please refer to a standard fluorescent wiring diagram to see how this series wiring works, and then maintain the existing wiring so that the supply is still externally supplied to both ends in _series_
The problem in rewiring the fitting so that current is only supplied at one end, and the other ignored (which does seem at first sensible and tidy), is that in the future someone may replace an expired LED tube with another, however with that ones shorted end across the supply.
Bang!
(If you have done that, probably wise to scribble a warning with a permanent pen to remind ye which end of the tube should be fitted to supply)
Reply to
Adrian Caspersz
Thanks for the reply. This is only partially correct though, unless I'm misunderstanding.
I've been replacing fluorescent tubes in my house and shed for a while now, only a couple to go. The first several I did were exactly as you say, the LED tubes were single end powered. This required an unshunted tombstone at one end, with hot and neutral connected to that end, and the tombstone at the other end was just mechanical support with no wiring to it. This is the way the installation instructions read for all single end LED tubes. It's also the simplest and easiest to rewire, you usually have enough existing wire length to at least one end. (yes, at least once my tube didn't light, because I'd put the wrong end in)
If I understand what you are trying to say, you would use an unshunted tombstone at the powered end, continue the circuit to a shunted tombstone at the other end, then back to the powered end, then to neutral??? I think that would trip the breaker immediately but maybe I'm not understanding. Remember the ballast is gone with these tubes. Or you could run wires in parallel, one hot and one neutral to both ends with unshunted tombstones, and it wouldn't matter if you put a single end LED in either direction. But accidentally putting a double end tube or an old fluorescent in would be a disaster.
But I've also used the double end LED tubes, where you run hot to one end and neutral to the other, and I tend to think these are safer. This is how the installation instructions read for the PlugPlay ones I mistakenly bought. The instructions for this type say either use shunted tombstones or pigtail the wire to both contacts of a shunted one. I'm not sure why that is necessary, seems like one pin would be enough.
It seems to me that direct wire tubes would be easier to design and manufacture than PlugPlay, and my evidence is that not all ballasts are compatible. But I have no idea what extra circuitry is involved, and would be interested if anyone would share.
Reply to
Tim R
Much depends on what you have been supplied, but the circuit awareness is good and better than the average Amazon purchaser that frankly scares me.
When I mean a 'shorted end', I mean that particular 'plug and play' LED tube _internally_ has a connection between the end two pins. In that case, the non-shunted tombstone wiring is then connected series as normal for florescent tubes and both the starter and ballast are removed and their connections linked across.
If you have been supplied a 'direct wire' tube with one end internally open circuit, of course you just connect it at the supply end, and there is no issue if that same tube is later inserted the wrong way - other than darkness, and the fear that a future Amazon shopper might purchase the wrong replacement type isn't your problem ...
I think that would trip the breaker immediately but maybe I'm not understanding. Remember the ballast is gone with these tubes. Or you could run wires in parallel, one hot and one neutral to both ends with unshunted tombstones, and it wouldn't matter if you put a single end LED in either direction. But accidentally putting a double end tube or an old fluorescent in would be a disaster.
On the tube it is a 50/50 shoot which pin is the active one. They both won't be common/shorted as again, what happens if the Amazon shopper inserts the tube into a unshunted fitting wired traditionally?
I think it is unsafe supplying tubes with internally shorted ends.
I just get rid of ballasts and starters.
But I have no idea what extra circuitry is involved, and would be interested if anyone would share.
Reply to
Adrian Caspersz
Some led tubes are designed to work with a magnetic ballast in circuit so they do not need rewiring. I consider that a safe approach since the tombstones are the same, a normal flurescent tube could be installed in the future. I have never seen a magnetic ballast fail.
Reply to
Jeroni Paul
I have seen lots of them fail. However this in buildings that have hundreds if not thousands of them. Replaced lots of them over the years.
The LED replacements did not come ito use before I retired. The elecrtronics were not in use for too many years before I retired so can not coment on their lifetime.
At home when the tubes went out I replaced them with direct wired LEDs.
Reply to
Ralph Mowery
I have never seen a magnetic ballast fail.
Yes, me too, and occasionally start a fire.
Reply to
Tim R
I am disappointed with their reliability. I maintain the lights in my bloc of flats and the lift lights years ago used CFL GU10 type bulbs. They were rated a lifetime of 20000h which are 2.5 years as they are always on and they actually lasted about 3.5 years.
Three years ago I installed GU10 led bulbs with a rated lifetime of 50000h, that's 6 years! After two years both bulbs failed with blinking lights. They did not even reach the rated lifetime of CFL. I also see many TV led backlights fail more often than CFL. For now I consider CFL quite more reliable than led.
Reply to
Jeroni Paul
You may be right. I've had good life from CFLs, even stopped writing the date on the base.
I haven't had an Led tube fail, but have had a couple of bulbs burn out. Still most are going strong. Might it depend on how the fixtures trap heat?
I've yet to see a traffic light where all the leds work.
Reply to
Tim R
There's a lot of bad design/assembly choices being made in led replacements for long-tube ccfl replacements.
These stem from thermal expansion differences between the led chip carrier medium and the housing. FR4 doesn't cut it.
The use of adhesive simply causes bowing and thermal isolation, with added mechanical stress on the joints and thermal stress on the semiconductor.
The addition of screw tie-points doesn't correct for this - it simply determines where the bowing will occur.
Only those strips that use a viable thermally conductive substrate and a slide-able attachment scheme can benefit from semiconductor reliability, to demonstrate a long operating life.
RL
Reply to
legg
The brand Peter found was delivered, packed in an unusual cardboard mesh wrap.
I had already wired the fixture for double end power but as they were unshunted tombstones converting to single end was easy. They are much brighter than the plugplay ones, but not as bright as I'd hoped. I'll post again when they burn out. Anybody had one of these fail?
Reply to
Tim R

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