From: clewis@ferret.ocunix.on.ca (Chris Lewis)
Newsgroups: misc.consumers.house
Subject: Re: Dealing with ungrounded outlets
Date: 15 Oct 92 05:04:39 GMT
Organization: Elegant Communications Inc., Ottawa, Canada

In article <1992Oct14.203118.28764@news.arc.nasa.gov> doshay@ursa.arc.nasa.gov (David Doshay) writes:
>In article <1992Oct14.183011.4407@ulysses.att.com>, smb@ulysses.att.com (Steven Bellovin) writes:
>|> In article <DRAND.92Oct12111042@spinner.osf.org>, drand@spinner.osf.org (Douglas S. Rand) writes:
>|> >    The other area of concern is bedroom where we
>|> >    want to put a computer.  It has 2 prong
>|> >    outlets.  Will replacing these with GFIs be
>|> >    sufficient?

>|> > Yes.  Find the first outlet on the branch (usually tracing the wiring 
>|> > in the basement is easiest) and replace it with the GFCI outlet.

>|> Umm...  I'm not certain I agree with that.  A GFCI will certainly provide
>|> protection for *you*.  It won't provide a good solid ground for the
>|> electronics in the computer, nor for any surge suppressors.

You remembered! ;-)

>You must provide a ground. The GFI needs a ground to work.

I'm required to tell you that you've committed USENET offence #10,372:
Asserting that a GFCI outlet requires a ground to operate.

Penalty: sitting through 100's of postings and mail messages telling
you it isn't true.  Plus the occasional side flame-war about "does so!",
or whether the test button should work.  ;-)

No.  A GFCI works by detecting any difference in hot and neutral current
flow with a toroidal transformer.  The test button will also work properly.
The ground is irrelevant to GFCI operation.  GFCI's are an approved method
for upgrading 2 prong outlets for the protection of people.  In fact,
most codes will require either a GFCI or an installed ground if you
have to renovate 2-prong wiring for any reason.

The Wiring FAQ, CEC, NEC and Leviton (a major GFCI manufacturer) all say so.

The Wiring FAQ covers this in exhaustive detail.

>I cannot think of why your computer needs to be on a GFI circuit.

It protects you from defective cabling or little kids putting their fingers
in the socket.  It can't hurt.

Computers and other electronics (particularly digital) should have *real*
grounds.  This makes static zaps less likely to damage circuitry, particularly
on interfaces to devices in other chassis.  Ie: the monitor, modem,
printer or a terminal.

Furthermore, most surge suppressors need a ground to operate properly.
[Any surge suppressor with MOVs or other over-voltage device connected
to the ground prong will not work properly without a ground.]

For this particular purpose, the original poster is best advised to
run (or fish) a wire from the outlet back to a water pipe (as long
as it's continuously conducting back to the water main) or the panel
itself.  14ga or larger is best for this.  The GFCI is optional, but
recommended.

Though, if he's lucky, and it was wired in conduit or BX, he may
simply be able to connect the third prong to the outlet box.
But the armour has to be continuous back to the panel, and be
electrically sound.
-- 
Chris Lewis; clewis@ferret.ocunix.on.ca; Phone: Canada 613 832-0541
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