mysterious outlet wiring question

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On Sun, 11 Nov 2007 17:12:05 -0500, "RBM" <rbm2(remove

If the two white wires are connected to the same outlet terminal, as they were, isn't this doing what you mention?
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On Sun, 11 Nov 2007 17:12:05 -0500, "RBM" <rbm2(remove

And is it possible for a GFCI be placed on this circuit, or on the other outlet that is sharing the neutral, or on both?
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The danger, and the reason the neutral can't be dependent upon a device, is that if there is an open neutral situation, you get a 240 volt circuit feeding 120 volt devices. It is much more reliable to splice them independently and pigtail the outlet. Yes, you can install a GFCI on either of the circuits
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On Sun, 11 Nov 2007 17:49:17 -0500, "RBM" <rbm2(remove

Haven't I created an open neutral situation by disconnecting this outlet and leaving the hot return wire disconnected?
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The only wires you want to keep together are the whites. There are two circuits involved, the red wire was on one of them and in the box, you'll find two black wires spliced together, they are the second circuit
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I am not sure if this is what you have. But upon first reading, this sounds like a shared neutral. If refrigerator and washer/dryer are not on separate phases, then a very dangerous fire hazard exists. Both circuits should be a dual circuit breaker so that if one circuit trips, then both trip.
If both circuits share a common neutral, then a GFCI in the circuit breaker box with constantly trip and both circuits must be GFCIed. But refrigerators must not be on a GFCI according to code.
If it is a shared neutral, the best solution is to run a new circuit either to refrigerator or to washer dryer. A shared neutral must be performed with care to avoid fire.
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How can I tell if the are on separate phases or not?

They are on separate breakers.

I put the GFCI on one outlet (The washer/dryer with the one red line and the two whites), seems to work fine. I tried it on the refrigerator line but it kept tripping.
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Appreciate the concept. Determining what is good and bad by only testing is risky. View correct wiring AND verify it separately with numbers. Few problems are as dangerous as an improperly implemented shared neutral.
Route an extension cord from refrigerator outlet to washer room. The hot wire (smaller flat plug hole) from refrigerator to washer circuit hot wire must measure 240 volts. The hot wire from each hot wire receptacle to both neutrals (wider flat hole) (4 measurements) must measure 120 volts.
Finally, wire colors in refrigerator and washer receptacles should match colors attached to breaker box circuit breakers. Discover each circuit breaker positioned in box on opposite phases. Only then do you know (with certainty) that neutral wire will not be overloaded; create a fire.
Reason for putting both circuits on a dual breaker: 1) while working on one circuit, voltage from the other circuit would not accidentally shock the worker. And 2) it would make it obvious that this is a shared neutral - the next person should not make a mistake. Even if you don't install that dual breaker, still, absolutely verify the refrigerator and washer are on opposite phases.
A shared neutral will (should) not trip GFCIs in either receptacle. The fact that a refrigerator GFCI trips would make me nervous (not as nervous over the shared neutral). However, once that problem is resolved, code says to not use a GFCI on refrigerators.
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Horsepuckey.
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Regards,
Doug Miller (alphageek at milmac dot com)
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Doug Miller wrote:

In fact, the NEC requires plug-in refrigerators and freezers in commercial kitchens to be GFCI protected.
--
bud--

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There is, however, no generalized prohibition on using GFCIs with refrigerators, as w_tom claimed.
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Doug Miller (alphageek at milmac dot com)
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On Mon, 12 Nov 2007 18:13:04 GMT, snipped-for-privacy@milmac.com (Doug Miller) wrote:

In fact the only place it is even referenced is in 210.52(B)(1)ex2 where they allow a dedicated receptacle for the fridge that is not "serving the countertop" . That may be gone in 2008. I still haven't seen the final copy.
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snipped-for-privacy@aol.com wrote:

Sorry - I intended to agree with you and "put another nail in the coffin".

I see they are out at Barnes & Noble.
--
bud--

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That depends on the breaker box, but generally speaking, odd-numbered breakers are on one leg, even-numbered breakers on the other leg, e.g. (with the two legs labelled A & B):
1 ------- A -------- 11 2 ------- B -------- 12 3 ------- A -------- 13 .. 10 ----- B -------- 20

Bad idea, but not necessarily a Code violation.

That's why you shouldn't put a refrigerator on a GFCI.
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Doug Miller (alphageek at milmac dot com)
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Back in one of your earlier posts you said:
"Yes, if I turn on the breaker, I get 110v between the red wire and *one* of the white wires.
If I test between the red wire and the *other* white wire, I get 220v."
This proves that you are on separate phases
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washers and refrigerators shouldnt be GFCI protected because they false trip. one day you will be away and come home finding your fridge is warm because it false tripped.
washers may work fine for mmonths then trip out.
I have PERSONAL EXPERIENCE:(
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On Mon, 12 Nov 2007 07:17:14 -0500, "RBM" <rbm2(remove

That's what I was thinking... and since I disconnected the outlet without turning the other shared neutral circuit off, it I had been on the same phase wouldn't I have sent that circuit 240v and blown up the refrigerator?
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If you had both hot legs live, then separated the neutrals, you would create a 240 volt circuit, however if more than one thing was connected to that circuit, they would be in series and would be sharing that 240 volts
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Got a cite for that?
I didn't think so.
Putting a refrigerator on a GFCI is a dumb idea, but it's not a Code violation.
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Doug Miller (alphageek at milmac dot com)
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wrote:

Yes, you created an open neutral by disconnecting the receptacle. The neutrals should be pigtailed together so this cannot happen. You saw what kind of hazard opening the neutral can create. Your wire routing is incorrect if the black wire feeding the refrigerator does not come through this box but everything will work normally if you just pigtail the white wires and connect the pigtail to the line neutral terminal of the GFCI outlet. Connect the red wire to the line hot terminal of the GFCI outlet. Connect the ground, if used. All will be fine.
Don Young
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