Path: utzoo!utgpu!news-server.csri.toronto.edu!rpi!zaphod.mps.ohio-state.edu!uwm.edu!bionet!ames!skipper!rando
From: rando@skipper.dfrf.nasa.gov (Randy Brumbaugh)
Newsgroups: sci.electronics
Subject: Re: polarity
Summary: heck yes it matters
Keywords: polarity, stupid, babooze
Message-ID: <889@skipper.dfrf.nasa.gov>
Date: 23 Apr 91 20:10:37 GMT
References: <11864@jarthur.Claremont.EDU>
Distribution: usa
Organization: NASA Ames-Dryden FRF, Edwards, CA
Lines: 20

In article <11864@jarthur.Claremont.EDU>, cliff@jarthur.Claremont.EDU (Clifford Stein) writes:
> What's the purpose of polarized wall outlets with an AC
> signal?  I don't understand.   Is it really bad to force
> something to plug in the wrong way?

There is only AC potential at one blade of an ordinary 120v AC outlet 
(the hot side).  Inside the outlet it is wired with black wire to
make it easy to tell from the neutral, which should be near ground
potential.

For safety, outlets are designed so that it is possible to plug in
a connector only one way.  This allows all switches, fuses, etc.
to be placed in the hot, high potential side. Also, a light socket
is much safer if the small button contact at the bottom is hot
and the outside shell is neutral -- much less shock hazard.

If a plug is somehow forced in wrong, the equipment will still work,
but an electrical hazard is created.

Randy Brumbaugh  rando@skipper.dfrf.nasa.gov