- I direct wired Plug and Play LEDs, is this bad? - 2 Updates
| Adrian Caspersz <email@here.invalid>: Sep 15 12:55PM +0100 On 14/09/2022 11:54, Tim R wrote: > 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. 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) -- Adrian C |
| Tim R <timothy42bach@gmail.com>: Sep 15 06:14AM -0700 On Thursday, September 15, 2022 at 7:55:46 AM UTC-4, Adrian Caspersz wrote: > supply) > -- > Adrian C 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. |
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