GFCI Shared neutral

[TiredDude]

My kitchen counters did not have GFCI protection.

The outlets are on a shared neutral circuit, but all the outlets are on the same hot (red). There is another hot (black) that runs through the boxes in the back.

The only way I have found to get GFCI receptacles to work is to wire one for each receptacle on the line side nothing on the load and getting protection on individual outlets.

I can not run new wire here as it is armored cable behind ceramic tile backsplash.

Is there any way to get all of these outlets protected by one GFCI?

I tried passing the hot on the load side and not the neutral, but it didn't work, the downstream outlets remain hot when the GFCI trips.

I resorted to wiring like the attached (although all on red) way but it looks goofy with 4 GFCI outlets in a row.

 

[pattenp]

It's my understanding that GFCI outlets just don't work properly on a multiwire branch circuit where you have a shared neutral. The solution is to use a 2 pole GFCI breaker in the panel. I just don't have any experience working with GFCI's on MWBC's.

 

[rlitman]

Why are you insistent on wiring everything off one GFI?
Just buy a three pack (or several), and be done with it.

 

[Charles (in GA)]

Might look "goofy" but probably the only way you will make it work without rewiring.

Charles

 

[TiredDude]

Why are you insistent on wiring everything off one GFI?
Just buy a three pack (or several), and be done with it.

I did wire each up separately, and they work fine. Originally, I spent a lot of time trying to get them working off one GFCI, but gave up and put in the individual GFCIs.

But it has bothered me ever since. Then I read a home inspector on another forum said that multiple GFCIs in the kitchen is a flag for a hack DYI job. This bothered me too, so I thought I would post it here if anyone had an answer.

 

[TiredDude]

Might look "goofy" but probably the only way you will make it work without rewiring.

Charles

I think you are right. I found directions for doing it if you split the neutrals after the GFCI but I can't do that.

 

[gatchel]

I did wire each up separately, and they work fine. Originally, I spent a lot of time trying to get them working off one GFCI, but gave up and put in the individual GFCIs.

But it has bothered me ever since. Then I read a home inspector on another forum said that multiple GFCIs in the kitchen is a flag for a hack DYI job. This bothered me too, so I thought I would post it here if anyone had an answer.

Doesn't the code say you need more than one counter circuit in the kitchen hence the need for two or more GFCI outlets?

 

[rlitman]

Yep. Multiple GFI's in a kitchen does not say hack job.
It could indicate that GFI's were retro-fitted to an existing install (like yours).
I prefer separate GFI's when it could be confusing to search out a tripped one.

 

[TiredDude]

Yep. Multiple GFI's in a kitchen does not say hack job.
It could indicate that GFI's were retro-fitted to an existing install (like yours).
I prefer separate GFI's when it could be confusing to search out a tripped one.

Thanks mate. Appreciate your thoughts. No one wants to think they are a hack!

 

[VHF]

The outlets are on a shared neutral circuit, but all the outlets are on the same hot (red). There is another hot (black) that runs through the boxes in the back.

You might want to have some of the GFCI recepticals hooked to the black hot instead of the red. Presumably the black hot is your "other" kitchen circuit.

Originally (before GFCI) the recepticles were probably split--top half on one circuit (red) and bottom half on the other circuit (black). This is how my 1970 tract house in Wisconsin was wired. I had to do the same thing--put a GFCI receptical at every outlet.

Since you have two kitchen circuits, try to divy up the load. Ideally high-power applicances that might be used at the same time should be on different circuits (for example, toaster and microwave).

 

[sberry]

They work on mwbc. I have a couple.

 

[TiredDude]

You might want to have some of the GFCI recepticals hooked to the black hot instead of the red. Presumably the black hot is your "other" kitchen circuit.

Originally (before GFCI) the recepticles were probably split--top half on one circuit (red) and bottom half on the other circuit (black). This is how my 1970 tract house in Wisconsin was wired. I had to do the same thing--put a GFCI receptical at every outlet.

Since you have two kitchen circuits, try to divy up the load. Ideally high-power applicances that might be used at the same time should be on different circuits (for example, toaster and microwave).

Yeah, good advice, but not really practical for me - the black doesn't have enough slack for me to cut and pigtail in to, it just runs through the boxes.

And in my case, the receptacles were always on red.

 

[TiredDude]

They work on mwbc. I have a couple.

They will work, either as a single outlet protection or will work if you split the neutrals. I can't split the neutrals. As I understand it, you can not share the neutral downstream from the GFCI as the GFCI would see the current on the neutral but not on the hot and trip.

 

[walrus]

They work on mwbc. I have a couple.

My shop is all MWBC with GFIs

 

[2ManyProjects]

My kitchen counters did not have GFCI protection.

The outlets are on a shared neutral circuit, but all the outlets are on the same hot (red). There is another hot (black) that runs through the boxes in the back.

The only way I have found to get GFCI receptacles to work is to wire one for each receptacle on the line side nothing on the load and getting protection on individual outlets.

I can not run new wire here as it is armored cable behind ceramic tile backsplash.

You might want to have some of the GFCI recepticals hooked to the black hot instead of the red. Presumably the black hot is your "other" kitchen circuit.

Yeah, good advice, but not really practical for me - the black doesn't have enough slack for me to cut and pigtail in to, it just runs through the boxes.

I don't quite understand this.

If that wiring is indeed Type BX or MC armored cable or similar, the individual conductors would necessarily start out all being the same length, including in that portion where the outer jacket/armor was possibly removed to "run through the boxes" -- and more importantly, to make the existing connections to the outlets, which implies some extra length of cable INSIDE the box. In which case, there SHOULD be more than enough slack in that unused black wire to make a splice/pigtail. Perhaps the extra is coiled up somewhere in the back of the box, where it may not be immediately obvious?

OTOH, if during the original install, the cabling was first cut into chunks and then stripped to get bare ends at each box, then presumably so too would the black wire be cut (and of course rejoined, probably with a wire nut). So again, it would seem that a pigtail SHOULD be feasible.

A third possibility: I'm "reaching" a bit here, but is there any possibility that the wiring is NOT really "armored cable", per se, but instead are individual conductors (such as THHN or such) run through flexible conduit? If so, you MIGHT be able to use the old wiring as a pull rope to install new wiring in that same conduit.

And in my case, the receptacles were always on red.

Given that you already have that second Hot wire (hence, a second breaker/circuit) SO close, you really ought to take advantage of it, if you possibly can.

They will work, either as a single outlet protection or will work if you split the neutrals. I can't split the neutrals. As I understand it, you can not share the neutral downstream from the GFCI as the GFCI would see the current on the neutral but not on the hot and trip.

That is correct.

 

[MrMark]

They will work, either as a single outlet protection or will work if you split the neutrals. I can't split the neutrals. As I understand it, you can not share the neutral downstream from the GFCI as the GFCI would see the current on the neutral but not on the hot and trip.

Right. You are out of luck with your current cabling.