From: blockedofcourse@foo.invalid   
      
   I am using devices like this:   
          
   as volt-free interfaces to the signalling from smoke and CO detectors.   
      
   The mains connections are visible (BK/WH).  The balance are connections to   
   the isolated form C contacts, the "signal" wire from the detector(s)   
   and a nominal 9VDC supply (that I would like to avoid using).   
      
   First question:  does the "device" count as a regular "device" in   
   terms of volume computations?   
      
   Also, there are separation requirements from the mains when sharing a box.   
   Aside from a split enclosure, I can't see how you can guarantee that   
   given the rats nest you find in most boxes!   
      
   Second question:  how would such a device typically be deployed to   
   satisfy those requirements (the documentation accompanying it is   
   ridiculously sparse).   
      
   Third question:  if I use the contact to deliver mains voltage to something   
   like a small indicator (forfeiting the galvanic isolation) and optically   
   couple that state across the boundaries of the enclosure, what can you   
   recommend (*listed*!) inside the box?   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)