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I have a multiwire branch circuit (MWBC) connecting my dishwasher and disposal that connects to a Cutler-Hammer (using Eaton breakers) panel. After a renovation, an inspector told me I need the dishwasher to have an accessible GFCI break point, and of course, everything has to be AFCI too.

Apparently, an 'accessible' break point does not include the outlet that the dishwasher plugs into, because it is behind the dishwasher. So, that would mean I need a GFCI/AFCI breaker on the circuit. Since it is an MWBC, it appears what I need is a 2-pole GFCI/AFCI combo for my panel. But the problem is, I don't think Eaton (Cutler-Hammer) has a 2-pole GFCI/AFCI, type CH (to fit this panel).

So I don't know what to do: the breaker I need doesn't seem to exist, but code seems to indicate this non-existent breaker is the only solution. Does anyone know what to do here? Maybe I'm wrong about what I need?

Thanks in advance.

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  • But since there's only one neutral with the MWBC, the second breaker wouldn't work, right?
    – Mike
    Commented Aug 29, 2022 at 15:07
  • Darn, I think you are right. There would be no way for the gfci breaker to "know" if the returning neutral current was for it, rather than the other breaker. You can install GFCI outlets on a MWBC, but I agree with you, not breakers. Can you move the outlet for the DW to under the sink? That's what I always do for plug connected DWs. Since it will all be covered by cabinets/DW, cosmetics aren't all that important, I would think. Sorry for the bad suggestion. Commented Aug 29, 2022 at 16:12
  • EDIT, reposted comment: I was wrong on this suggestion, I don't want to mislead anyone so I'm reposting (can't edit comments). My suggestion won't work. Sorry to anyone who took it as gospel, I was wrong. Here is the original comment: You don't need a 2 pole GFCI/AFCI breaker. 2 GFCI/AFCI breakers will suffice as long as they are next to each other, on opposite hot legs and they are handle tied. Commented Aug 29, 2022 at 16:14

2 Answers 2

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A "deadfront" GFCI, AFCI, or both is a means to have the reset/test "Accessible" without having to have it "as a breaker." But, a deadfront AFCI has to have the circuit in metallic conduit to that point to qualify - a deadfront GFCI does not have that requirement.

But you have an MWBC. No big deal, you already split the MWBC into its 120V receptacles, just make that split before the deadfront device(s).

Image from Legrand website, no endorsement implied

So, you wire in a box in an accessible location, route hot1 and shared neutral to one GFCI, route that GFCI protected hot1 and neutral1 to dishwasher receptacle (or hardwire.)

Route hot2 and shared neutral to another GFCI, route that GFCI protected hot2 and neutral2 to disposal receptacle (or hardwire.) Or perhaps that one can be a normal GFCI receptacle if it's plug-in and acessible.

Two-pole AFCI CH breakers appear to be available, but pricy.

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  • I understand this solution and Eaton does have a 2-pole breaker that works, the CH215CAF.
    – Mike
    Commented Aug 29, 2022 at 15:25
  • Another thought occurred to me. If I have to add this extra blank front box in an accessible place anyway, couldn’t I just put an afci/gfci outlet from the current MWBC circuit under the sink, and add a long cord to the dishwasher that goes through a hole and to that new outlet? Then I don’t have to change the breaker. That 2-pole breaker is insanely expensive.
    – Mike
    Commented Aug 29, 2022 at 21:14
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    If you need to add AFCI protection, and the wiring is NOT already in metallic conduit, you are stuck with the insanely expensive breaker, or replacing the breaker box with one that has less insanely expensive breakers available, or running a sub-panel off the current breaker box that has less insanely expensive breakers available and moving the MWBC feed to that panel.
    – Ecnerwal
    Commented Aug 30, 2022 at 0:30
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AFCI requirements

I don't understand. Why did you run a new MWBC in this day and age? These kinds of problems are exactly why people stopped using them.

If you're using an existing MWBC, then that is a different kettle of fish. The existing circuit should be grandfathered as long as it was legal at the time it was installed. In that case it either a) does not need AFCI at all, or b) you are allowed to follow the AFCI retrofit rules, and install the AFCI at the first junction box past the panel. In the case of an MWBC, you better split the MWBC there because you will not find a 2-pole AFCI deadfront.

GFCI requirements

That is correct. In a kitchen remodel, a dishwasher needs to be GFCI protected. The GFCI protection can be at any suitable location, noting that all GFCI devices must be in readily accessible locations. You can't put them on ceilings or in ungainly locations, and that may well include behind a bunch of pipes in the kitchen sink cabinet. Depending on how the AHJ sees it.

Disconnect requirements

Dishwashers require a disconnecting means that is either in line of sight or lockable. That is so someone doesn't turn the breaker on while the repairman is servicing the dishwasher. However, my understanding is that a receptacle behind the dishwasher will suffice for this.

However, a recep behind the dishwasher cannot be GFCI because it is not readily accessible. What can we do? A GFCI "deadfront" in an accessible location is one way to do that, but those are not rated for switching duty, so a separate disconnect would be be required. That's awkward. What can we do? -->> See Ecnerwal's answer. That illustration is of a GFCI switch. It is like a GFCI deadfront, but up-rated for switching duty.

Whether you can get a GFCI+AFCI+switch, I do not know.

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  • It's an existing circuit. As you point out, the inspector said to pass, it now needs to be GFCI protected. Whether this is his interpretation or not, it turns out now that I'm messing with the circuit to add GFCI, it also must be AFCI. These cascading errors and requirements have already cost me thousands more than expected, so I got the inspector on the phone, and he said I could do something essentially as Ecnerwal suggested.
    – Mike
    Commented Aug 30, 2022 at 18:06

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