From: JERONI.PAUL@terra.es   
      
   Peter W. wrote:   
   > > I don't understand how that small voltage drop in the cabling causes an   
   imbalance in current. The earth in all appliances is supposed to be fully   
   isolated from the hot/neutral isn't it?   
   > A sensitive GF device will detect a difference between flow to the neutral   
   and the ground, and perceive this as current going to ground.    
   >    
   > The ground and neutral are bonded within the main panel, and there is a   
   secondary ground feeding the main panel.    
   >    
   > So, the full path of each circuit Neutral is from each device to the panel,   
   where it is bonded to a local ground. From there to the Utility Transformer -   
   which is also grounded in its location.    
   >    
   > The full path of each circuit Ground is from each device to the panel, where   
   it is bonded to the neutral and a local ground. It stops at the local ground.    
   >    
   > In theory, the Neutral and the Ground should be at equal potential - thereby   
   avoiding false trips - as that is what the GF device is looking for - current   
   going to Ground (or somewhere), not Neutral. If the Ground and Neutral are not   
   at equal potential    
   - there may be something for the GF device to detect.   
   > Peter Wieck    
   > Melrose Park, PA   
      
   Thanks for explaining.   
   I seem to understand that the GF built in your wall plugs (we do not have them   
   here) trips because the small voltage between neutral and ground. That does   
   not look like the right thing it should trip on. Even if the installation has   
   few interconnects if    
   you plug a heavy load the drop will develop anyway.   
      
   Here in 230/400V areas there is no voltage between neutral and ground (they   
   could also be joined at the panel) but if you short them in a plug the GFCB   
   trips, this is because the small voltage drop developed in the cabling.   
   Shorting them creates a    
   parallel path and current will distribute proportionally, some current will   
   flow through earth instead of neutral.   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)