GFCI - MWBC - GD, DW, SBAC

[ESolar]

Why am I not seeing this as standard for MWBCs in this application? Any issues here? (Note the dead front is not an outlet even though it states as such)

 

[retirede]

Since you need 2 SABCs anyway, I think that would be a better place to run a MWBC.

Since most places now require AFCI as well, it may be more cost-effective to use dual-function breakers without the MWBC.

 

[ptonsparky]

The dead front is considered an outlet by definition.

 

[infinity]

Why am I not seeing this as standard for MWBCs in this application? Any issues here?

No issues if as retirede stated you do not require AFCI protection. If so then running two separate two wire circuits is probably better.

 

[rc/retired]

Why am I not seeing this as standard for MWBCs in this application? Any issues here? (Note the dead front is not an outlet even though it states as such)

View attachment 2567746

Well, I might be confused.
In a commercial kitchen, I have no problem with the drawing. However, (there's always a however in life), in a residential kitchen, this is incomplete.
For residential, as stated, a dual function breaker is the way to go.
But, the SABC that supplies the the disposal and dishwasher does NOT meet the requirements for the 2nd SABC for residential kitchen counters.

Ron

 

[jaggedben]

In existing houses I most often see the GD and DW on an MWBC, and then 2 separate SABCs on single poles since AFCI has been required for those for a while now. I see a fair number of houses where the GD and DW is the only MWBC. Probably because they reliably go to the same place and so guys with a general prejudice against MWBCs make an exception there.

Having the GD and DW on the same circuit probably is fine most of the time ... until someone drops a fork in the GD while the DW is on the heat cycle. Just guessing, not from experience.

(As an aside, when labeling panels, please don't use 'GD' for both the disposal and the garage door. Also the inscrutable acronym soup here is hilarious, and I'm just going with it.)

 

[rc/retired]

(As an aside, when labeling panels, please don't use 'GD' for both the disposal and the garage door. Also the inscrutable acronym soup here is hilarious, and I'm just going with it.)

I cannot agree more!

Ron

 

[Tulsa Electrician]

Using NM,would code require a grounded conductor in the switch outlet. Or would it be exempt for a motor.

 

[LarryFine]

Also the inscrutable acronym soup here is hilarious, and I'm just going with it.

"Excuse me, sir. Seeing as how the V.P. is such a V.I.P., shouldn't we keep the P.C. on the Q.T.? 'Cause if it leaks to the V.C. he could end up M.I.A., and then we'd all be put on K.P." ~ Robin Williams as Adrian Cronauer in Good Morning, Vietnam

 

[ESolar]

The common 1990's wiring here are two MWBCs: GD/DW - SBAC, and Microwave-SBAC. AFCI was not required recently. I'm concerned that because they just switched to 2020, they are going to flag for AFCI.
Re ARE, ALOL, AFN.

 

[ESolar]

Using NM,would code require a grounded conductor in the switch outlet. Or would it be exempt for a motor.

I use it. Just not shown. Thanks.

 

[rc/retired]

Re ARE, ALOL, AFN.

Huh?

 

[ptonsparky]

Huh?

Thank you.
I've already used up my 'huh' for the week.

 

[electrofelon]

.

Having the GD and DW on the same circuit probably is fine most of the time ... until someone drops a fork in the GD while the DW is on the heat cycle. Just guessing, not from experience.

I did a house a few years back with both on the same circuit. HO got a 3/4 HP disp, and the DW has a rather high nameplate so it was technically out of code (doubt it would have ever tripped) and the inspector caught it. HO changed disp to a 1/2 HP and wasn't mad, said he'd use the 3/4 elsewhere. Just recently I did 4 townhomes and also did the DW and disp on same circuit, because it was a rather cheap bid job. I knew they would use small cheap DW and disposals and it was fine. Inspector did scold me for "limiting future options for the homeowner". I wanted to smack him so bad, shut the hell up, go get your own 4 unit town home job and you can do it however you want .....

 

[ptonsparky]

Has anyone had a DW and Disposal on the same circuit that tripped the breaker during normal operation?

 

[LarryFine]

At least he acknowledge the difference between code and preference.

 

[electrofelon]

At least he acknowledge the difference between code and preference.

I don't mind a friendly recommendation or a "heads up some combinations of DW/disp exceed a single circuit", but he was condescending.

 

[infinity]

I don't mind a friendly recommendation or a "heads up some combinations of DW/disp exceed a single circuit", but he was condescending.

They're permitted on the same circuit if the two units do not exceed the circuit ampacity so what was the total current in relation to the branch circuit size?

 

[electrofelon]

They're permitted on the same circuit if the two units do not exceed the circuit ampacity so what was the total current in relation to the branch circuit size?

I forget the specifics, but in the first case they were indeed over a 20 amp circuit

 

[ESolar]

Huh?

ARE - Acronym rich environment
ALOL - Actually laughing out loud
AFN - That's all for now
.
If I keep this up I might get B& (acronym for banned)