From: peterwieck33@gmail.com   
      
   > If you can plug a polarized plug into a non-polarized receptacle, then    
   > you can defeat the safety advantage offered by the polarized plugs.   
      
    NEMA receptacles (1-15P) for polarized plugs have been around since the late   
   1920s when the concept of 120/240 AC systems was fully described. We have them   
   in some old wiring in our house. NP (1-15) receptacles exist for situations   
   where the polarity of    
   the receptacle cannot be predicted - such as DC circuits, and 'back-panel'   
   receptacles in devices such are clock-radios that might be plugged into the   
   wall either way. Many more contemporary audio devices used NP receptacles in   
   the back (especially tube    
   stuff)  rather than polarized as they sometimes hummed less if plugged in one   
   way rather than another.    
      
   Polarized *receptacles* offer 'safety advantages' only if they are correctly   
   wired.    
   Polarized *plugs* offer safety advantages again, only if they are properly   
   wired and the device is functioning properly.    
      
   These distinctions are lost on our Non-North American friends. After all, it   
   was all pretty much invented here, and the rest of the world benefitted by not   
   having to make the same mistakes we did in the beginning. Nor are they living   
   with 110 year-old    
   wiring as we are (1913). It is perfectly fine, by the way, and called "knob   
   and tube". It has also been inspected by our insurance company and passed   
   without a peep.    
      
   Peter Wieck   
   Melrose Park, PA    
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)