From: clewis@ferret.ocunix.on.ca (Chris Lewis)
Newsgroups: misc.consumers.house
Subject: Re: GFI question
Date: 12 Apr 92 07:04:40 GMT
Organization: Elegant Communications Inc., Ottawa, Canada

In article <1992Apr10.12099b@f8.n154.z1.fidonet.org> jack@myamiga.mixcom.com (Jack Decker) writes:
|In article <3383@ecicrl.ocunix.on.ca> dated 9 Apr 92 04:32:53 GMT,
|clewis@ferret.ocunix.on.ca (Chris Lewis) wrote:

| > >>Remember that a GFI recepticle protects all recepticles further on the
| > >>circuit as well as itself.  You can also buy a GFI circuit breaker
|(although
| > >>these are expensive--about $35 - $50 last time I checked).
| >
| > Triple that - a split receptacle needs a dual GFI breaker.  Cheapest
| > one I've seen was $150CDN.  Note that Chris is posting from Canada.

|[stuff deleted]

| > In most cases, the only practical solution for Chris is to install
| > a (very expensive) dual GFI breaker.

|I'm going to stick my nose in here with the caveat that I probably don't know
|what I'm talking about (and I am ***NOT*** an electrician), but on the off
|chance I do, it might save someone considerable money.

|In converted mobile home electrical panels in homes going to Canada, the
|Ontario Hydro inspector has allowed (and in fact encouraged) us to make "dual"
|breakers by using two SINGLE breakers side by side with a small metal device
|called a "tie handle."  These are not that easy to find (usually only the
|electrical wholesalers have them) but on the other hand they are such an
|inexpensive item that one time a counter clerk just gave me a couple of them
|rather than go through the trouble of writing them up (other times the guy has
|said "just give me a quarter", which I suspect went into a petty cash box (or
|his pocket) after I walked out the door).

|The tie handle simply connects the plastic handles of two breakers together in
|such a way that you can't have one breaker on and the other off.

|Now, I don't *know* that a tie handle could be used to bridge the handles of
|two single GFI breakers to make a dual, but in the absence of a code provision
|that specifically states that it's not allowed, I'll bet you could get away
|with it.

	a) tie-bars aren't usually permitted in residential situations in Canada.
	   At least according to Knight's book.
	b) Most single GFI breakers take up two slots, so:
		1) It would be difficult to arrange two GFI breakers to
		   be on opposite sides of the 220V service.
		2) Would need a non-standard "long" tiebar.
	c) Moot: original poster has a *fuse* panel :-(

|But the "fly in the ointment" is that not only the BLACK wire passes through a
|GFI breaker, but also the WHITE wire.  Obviously, in feeding a split
|receptacle, you'd have to tie the two whites from the two GFI's together on the
|side feeding the receptacles.  For some reason I suspect this still might work,
|but maybe it would not (I have to wonder if it's ever been tried).

|If any electricians tell me this won't work, I'll take your word for it!

Several people on the net will tell you that this won't work.  GFI's work by
"summing" the current in the two current carrying conductors (remembering
that at any given moment the current is going in opposite directions in the
hot and neutral) and ensuring that the sum is zero.  If you tied the neutrals
together on the output of a GFI, the hot and neutral current would only sum to zero
in both GFI's if there's no current whatsover flowing in one of the hot legs. 
Not very useful.  A true dual GFI sums the current in all three wires.

Thus, to do this you'd have to run two neutrals to the outlet box.  Implying
two runs of 14-2, and potentially an expensive wall renovation.  Another
strike against this: CEC frowns on two seperate power cables entering a box.

|Failing that, my other question would be whether putting two standard GFI
|receptacles side by side in a duplex outlet box would satisfy the code, if each
|receptacle were fed from opposite sides of the 220 volt circuit.  In other
|words, on the left hand side you'd have one GFI with two outlets fed from Black
|and White, and on the right hand side you'd have another GFI fed from Red and
|White (with the white common to both receptacles).

The neutral would have to "Y" on the *line* side (input) of the GFI, not the
load (output/GFI protected) side.  So "common neutral" is misleading.

|In my mind, this would be
|the same as two split receptacles except the "split" would be between left and
|right instead of top and bottom.  I suppose the code wouldn't allow anything
|THAT sensible!

There's a good chance that they would permit this.  A little unusual,
but okay.
-- 
Chris Lewis; clewis@ferret.ocunix.on.ca; Phone: Canada 613 832-0541
Psroff 3.0 info: psroff-request@ferret.ocunix.on.ca
Ferret list: ferret-request@ferret.ocunix.on.ca
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