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#35517 - 03/12/04 06:35 AM Multiwire (Edison) circuits and GFCI
Sir Arcsalot Offline
Member

Registered: 11/17/03
Posts: 117
Loc: Lynden, Washington
I hope I don't get run out of Dodge by bringing up multiwire circuits (I still tend to call them Edison circuits even though the configuration, I believe, was intended for DC as Edison HATED AC as most folks know).

Anyway, I have two pairs of existing Edison circuits (four circuits total) that I do not intend to completely re-wire since they work just fine. However, one of these pairs feed the outlets in my kitchen which I would like to GFCI-protect; the second pair feeds the clothes washer and a freezer outlet which I'm debating about GFCI retrofitting.

My questions are:

1) I intend to use two-pole GFCI breakers to accomplish this- are they prone to nuisance tripping in this type of setup?

2) I heard somewhere that GFCI outlets can be used on these IF they are installed at the end of the circuit run(s); is this true?

Yes, multiwire or Edison circuits are like oysters, we either seem to love them or hate them (my brother despises them something fierce but I don't mind them myself); nonetheless, they do have their place. I do not intend to start a debate (war??) on this configuration but merely have some questions on GFCI protection on these types of circuits.

Thank you in advance.
_________________________
No wire bias here- I'm standing on neutral ground.

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#35518 - 03/14/04 06:18 AM Re: Multiwire (Edison) circuits and GFCI
electure Offline

Member

Registered: 12/24/00
Posts: 4226
Loc: Fullerton, CA USA
You can install GFCI receptacles on any section of a multiwire circuit, but cannot use the feed through option.
Your multiwire circuit's grounded conductor should be pigtailed at each outlet any way.
Just install the GFCI receptacles individually.
You will need a separate GFCI receptacle for each location...S

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#35519 - 03/14/04 07:19 AM Re: Multiwire (Edison) circuits and GFCI
Electric Eagle Offline
Member

Registered: 04/20/02
Posts: 928
Loc: Alpharetta, GA
You can protect both circuits on the multiwire by putting a GFCI outlet at the first outlet on each line after the circuit splits.

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#35520 - 03/14/04 10:50 AM Re: Multiwire (Edison) circuits and GFCI
Sir Arcsalot Offline
Member

Registered: 11/17/03
Posts: 117
Loc: Lynden, Washington
I think what I'll do is put a two-pole GFCI on the kitchen circuits and use solo GFCI outlet(s) on the other two circuits if/when I feel the need for them.

quote:

You can protect both circuits on the multiwire by putting a GFCI outlet at the first outlet on each line after the circuit splits.

I've heard that GFCI outlets do NOT like this on a multiwire configuration... I think electure's point on not using the feedthroughs may be the correct one... I just want to be sure. Maybe I didn't understand the comment correctly???


quote:

Your multiwire circuit's grounded conductor should be pigtailed at each outlet any way.

Indeed. You folks would not believe what I found when I bought this house (well, actually, maybe you would). Someone decided to use the backwire and sidewire slots on the duplex receptacle feeding the clothes washer to split up the circuits!!!!! If this was ever legal, I don't believe it ever should have been. If the device fails, subsequently opening up the neutral, well, you know... WOW! That washer NEVER spun those clothes so dry before Needless to say, I ripped it out and done it up right.

UTMOST CARE must be taken to ensure neutral integrity on multiwire circuits.

Again, I must thank the host(s) for this fantastic website, and thanks to all of you for your expert advice on matters such as this.




[This message has been edited by Sir Arcsalot (edited 03-14-2004).]
_________________________
No wire bias here- I'm standing on neutral ground.

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#35521 - 03/14/04 11:04 AM Re: Multiwire (Edison) circuits and GFCI
Ryan_J Offline
Moderator

Registered: 08/19/03
Posts: 1355
Loc: West Jordan, Utah, USA
I would agree with Eelctric Eagle on his response.

Remeber that A GFCI compares the difference between the ungrounded and grounded conductors downstream of the device, not upstream. The GFCI is blind about what is occuring before the device. As long each circuit has its own nuetral after the GFCI you should be OK.
_________________________
Ryan Jackson,
Salt Lake City

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#35522 - 03/14/04 03:55 PM Re: Multiwire (Edison) circuits and GFCI
Edward Offline
Member

Registered: 12/14/02
Posts: 309
Loc: California
I have installed GFCI on Shared neutral circuits but it kept triping. So i had to pull in an additional neutral.(flex job)
It was very strange to me because a GFCI does not see anyhting upstream from it. But it kept triping. I know there wasn't anyhting on the load side connected.


Edward
_________________________
Thanks
Edward

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#35523 - 03/14/04 04:21 PM Re: Multiwire (Edison) circuits and GFCI
Roger Offline
Member

Registered: 05/18/02
Posts: 1779
Loc: N.C.
Edward, I must ask, what did you mean by
 Quote:
i had to pull in an additional neutral.(flex job)


Roger

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#35524 - 03/14/04 04:25 PM Re: Multiwire (Edison) circuits and GFCI
iwire Offline
Moderator

Registered: 01/05/03
Posts: 4343
Loc: North Attleboro, MA USA
Ed there must have been something else going on.

The feed to any panel is essentially a multiwire circuit and GFCIs work down stream from there
_________________________
Bob Badger
Construction & Maintenance Electrician
Massachusetts

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#35525 - 03/14/04 04:35 PM Re: Multiwire (Edison) circuits and GFCI
Edward Offline
Member

Registered: 12/14/02
Posts: 309
Loc: California
What i meant was that the job was not romex. So i did not run just a grounded(neutral) wire through the studs. I ran an additional neutral through the flex.

I am not sure if there was anything else going on, because as soon as i connected the additional neutral all was working fine.

Edward
_________________________
Thanks
Edward

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#35526 - 03/15/04 05:52 AM Re: Multiwire (Edison) circuits and GFCI
earlydean Offline
Member

Registered: 12/22/03
Posts: 749
Loc: Griswold, CT, USA
Must have hooked them up backwards!
_________________________
Earl

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