Path: utzoo!utgpu!news-server.csri.toronto.edu!rpi!usc!cs.utexas.edu!rice!uncle-bens.rice.edu!kossackj
From: kossackj@uncle-bens.rice.edu (Jordan Marc Kossack)
Newsgroups: sci.electronics
Subject: Re: polarity
Summary: Leakage current?
Keywords: polarity, floating neutral, leakage curent, ZZAAAP!
Message-ID: <1991Apr30.071408.16711@rice.edu>
Date: 30 Apr 91 07:14:08 GMT
References: <11864@jarthur.Claremont.EDU> <889@skipper.dfrf.nasa.gov> <1991Apr27.174257.21380@sci.ccny.cuny.edu>
Sender: news@rice.edu (News)
Followup-To: sci.electronics
Distribution: usa
Organization: Rice University, Houston TX  (Victim of the 1990 Economic Summit)
Lines: 29

In article <1991Apr27.174257.21380@sci.ccny.cuny.edu> 
sukenick@sci.ccny.cuny.edu (SYG) writes:
>
>At the fuse box, ground (bare, green and/or cable shield ) and neutral
>(white wire)  are tied together.  Ground is usually
>tied to a pole in the ground and/or maybe the metal plumbing.
>The difference between ground and neutral is that neutral carries current,
>and since wires have some resistance, may be a few volts above ground.
>
	So, this makes me wonder if this is a cause of leakage current.  
   When I was working as an electronics tech, we sold some electronic
   stuff to hospitals and physicians and had to guarantee that the leakage
   current did not exceed a specified value.  To test a unit, we would 
   unground it and measure the leakage current between the metal enclosure
   and 'actual' ground.  At times, a physician or hospital would send one 
   back to us claiming excessive leakage current, but when I measured it
   on the lab bench, it was OK.  Could this have been caused by the neutral
   side of the circuit at the hospital floating too high above ground?  
 
	Any ideas?  OBTW, I'm not working there any more so I'm not trying
   to weasel out of meeting the specs.  ;-)  Thanks.

							- Jordan  

--
        +-------------------------------------------------------+
        |        Although robust enough for general use,        |
        |     adventures into the esoteric periphery of the     |
        |         C shell may reveal unexpected quirks.         |