From: email@here.invalid   
      
   On 14/09/2022 11:54, Tim R wrote:   
   > 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.   
      
   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   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)