From: email@here.invalid   
      
   On 15/09/2022 14:14, Tim R wrote:   
   >   
   > 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???   
      
   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.   
   >   
   > 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.   
      
   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.   
      
   >   
   > 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.   
      
   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.   
   >   
   >   
      
      
   --   
   Adrian C   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)