Kitchen Dishwasher and Disposal

[Naga]

Hi Guys,

Had a question. I am doing a job where the owner changed his kitchen cabinets and I had to take apart the disposal and dishwasher boxes and put new ones because the locations changed not more than a few feet. The inspector now says the disposal and dishwasher have to be Gfci only problem is I found out the circuits are being fed by a 12/3 mwbc so they are sharing the neutral. Can the dishwasher and disposal be considered grandfathered in so I don't need to make them GFCI or if they have to how do I make this work? Use a 20amp 2pole GFCI breaker?


Thanks,
Grant

 

[Dennis Alwon]

I would use a dp gfci. I have never heard that ruling about a mwbc. Only the inspector can answer whether or not they will require gfci. IMO, if you messed with it then you have to bring it to code.

 

[Little Bill]

It would also need AFCI if it's being forced to bring it up to code.

 

[infinity]

The inspector now says the disposal and dishwasher have to be Gfci only problem is I found out the circuits are being fed by a 12/3 mwbc so they are sharing the neutral

Not an issue if you use a 2-pole GFCI breaker.

 

[Dennis Alwon]

It would also need AFCI if it's being forced to bring it up to code.

Since the inspector didn't mention it I assume they may be under the 2017 or there is an amendment

Nope Hawaii is on the 2020

 

[Naga]

Since the inspector didn't mention it I assume they may be under the 2017 or there is an amendment

Nope Hawaii is on the 2020

 

[Naga]

Ok I can use a 2pole 20amp to make both circuits GFCI but if it has to be also AFCI what can I do? The Arc fault wont work on a shared neutral

 

[Buck Parrish]

Splice the neutral in a j-box before your dishwasher and disposal circuit. Then you can use gfci outlets.

 

[Dennis Alwon]

Splice the neutral in a j-box before your dishwasher and disposal circuit. Then you can use gfci outlets.

I think you mean afci receptacles

 

[Little Bill]

Since the inspector didn't mention it I assume they may be under the 2017 or there is an amendment

Nope Hawaii is on the 2020

AFCI was/is required in the 2017. That's what we're on now.

 

[Dennis Alwon]

AFCI was/is required in the 2017. That's what we're on now.

I forgot we have an amendment of the 2017-- no afci in kitchens

 

[electrofelon]

Another option may be to just put them both on a single circuit - depending on the name plate of each appliance.

 

[Eddie702]

Agree with @electrofelon make it one circuit. A DW usually can work on a 15 am circuit so a 20 will probably do the DW & the disposal

 

[electrofelon]

Agree with @electrofelon make it one circuit. A DW usually can work on a 15 am circuit so a 20 will probably do the DW & the disposal

Yeah probably find most of the time, but You do have to be a bit careful, I got zinged for this once where the dish and disposal were both on the larger side and the math didn't work out. The solution was the HO got the next size smaller disposal, like 1/3 horsepower instead of 1/2 or whatever it was.