# can a dishwasher and a garbage disposal share a neutral?



## Irishslave (Jun 20, 2010)

I was thinking running 14-3....both sides dedicated....yeah yeah I know opposite sides of the bus or you will potentially fry the neutral 

But aint this how it is usually done? You already need so much wiring for the kitchen this saves space and wire


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## Tinstaafl (Jan 6, 2008)

Ignoring the manufacturer's recommendation for dedicated circuits, I'd run 20A 12/3.


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## Irishslave (Jun 20, 2010)

Tinstaafl said:


> Ignoring the manufacturer's recommendation for dedicated circuits, I'd run 20A 12/3.


And you would what? Integrate recepticles on those (2) 20 amp circuits? Maybe tag one each for a light too? 

I'm trying to come up with a Kitchen plan that makes sense w/o overkill. 

NEC says at least (2) 20 amp circuits for a kitchen...plus a dedicated for the micro and frig


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## 480sparky (Feb 1, 2009)

The two 20a kitchen circuits (SABC's) cannot be used for either the dishwasher or the garbage grinder.

My SOP is to install a 20a circuit for both.

And yes, they can be wired a 12/3, *with a common disconnect*, and share a neutral.


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## Irishslave (Jun 20, 2010)

480sparky said:


> The two 20a kitchen circuits (SABC's) cannot be used for either the dishwasher or the garbage grinder.
> 
> My SOP is to install a 20a circuit for both.
> 
> And yes, they can be wired a 12/3, *with a common disconnect*, and share a neutral.


Wouldn't a common disconnect put both circuits on one bus? Geez I'm up to 6 circuits w/o lights


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## Tinstaafl (Jan 6, 2008)

Skimping on wire usage is a disservice to your client on more than one front, leaving aside any code issues. The responsible thing to do is not to wire to the absolute minimum requirement.

And with an eye to the future, I suspect that just about any shared-neutral circuits are going to be a problem down the road.


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## Seven-Delta-FortyOne (Mar 5, 2011)

Irishslave said:


> Wouldn't a common disconnect put both circuits on one bus? Geez I'm up to 6 circuits w/o lights


No.

And it's required by code.


Delta


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## Irishslave (Jun 20, 2010)

so now all MWBC's have to be on double pole breakers to comply?


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## 480sparky (Feb 1, 2009)

Irishslave said:


> Wouldn't a common disconnect put both circuits on one bus? Geez I'm up to 6 circuits w/o lights


Take a good look how buses in most panels are arranged.


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## TxElectrician (May 21, 2008)

Here, we are required to put all 120v 15 and 20 amp kitchen outlets on AFCI, not just counter top. May be easier to find single pole afci instead of 2 pole. If that is the case, you couldn't share neutral.


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## Leo G (May 12, 2005)

Around here the DW and disposal need to be on a single 2 pole breaker. So yes, they share a neutral. Personally I think it's stupid. It puts 220v in that box.


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## 480sparky (Feb 1, 2009)

Leo G said:


> Around here the DW and disposal need to be on a single 2 pole breaker. So yes, they share a neutral. Personally I think it's stupid. It puts 220v in that box.


There's 220 in your electric stove. There's 220 in your electric water heater. There's 220 in your well pump. There's 220 in your bubble tub. There's 220 in your welder. There's 220 in your air conditioner compressor. And there's 220 in your ENTIRE PANEL! Oh, the horrors! :laughing:


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## TxElectrician (May 21, 2008)

480sparky said:


> There's 220 in your electric stove. There's 220 in your electric water heater. There's 220 in your well pump. There's 220 in your bubble tub. There's 220 in your welder. There's 220 in your air conditioner compressor. And there's 220 in your ENTIRE PANEL! Oh, the horrors! :laughing:


I've got 221


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## Leo G (May 12, 2005)

Yes I totally understand that. But you expect it to be there. It's a 220 volt outlet so you expect 220v to be there. This is two 120v outlets with the capacity for you to get 220v out of it.

If you take wire and plug it into each outlets hot you get 220v. You don't get that with an ordinary outlet.

All this is to save 1 wire.

You are thinking like an electrician, not the normal moronic home owner.


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## TxElectrician (May 21, 2008)

Leo G said:


> Yes I totally understand that. But you expect it to be there. It's a 220 volt outlet so you expect 220v to be there. This is two 120v outlets with the capacity for you to get 220v out of it.
> 
> If you take wire and plug it into each outlets hot you get 220v. You don't get that with an ordinary outlet.
> 
> ...


That's why moronic HOs should call simeone qualified


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## Leo G (May 12, 2005)

Of all the codes I've seen written I've seen some pretty stupid ones because 1 person got themselves killed because they were a stupid HO. Yet a new code was written.

This is one of those codes that should have never been written.

They made a code that you can't put a panel box within 3 feet of a window because some stupid person reached in a window and killed himself off because he reached into the open panel.

That's a stupid code.


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## 480sparky (Feb 1, 2009)

Leo G said:


> Yes I totally understand that. But you expect it to be there. It's a 220 volt outlet so you expect 220v to be there. This is two 120v outlets with the capacity for you to get 220v out of it.
> 
> If you take wire and plug it into each outlets hot you get 220v. You don't get that with an ordinary outlet.
> 
> ...


Being an electrician, I expect just about ANY box can have 220 in it. Or 208. Or 480.

If said 'normal moronic home owner' gets zapped because they're a normal moron, oh well. They're free to kill themselves with their own stupidity. No law against that.


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## Leo G (May 12, 2005)

The codes aren't for the safety of electricians.


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## ComRemodel (Jul 5, 2016)

Leo G said:


> The codes aren't for the safety of electricians.


Obviously, since people seem to be getting dumber and dumber every code cycle has more and more ridiculous requirements to keep them alive. I say let Darwin do his thing. :whistling

-Hal


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## 480sparky (Feb 1, 2009)

ComRemodel said:


> Obviously, since people seem to be getting dumber and dumber every code cycle has more and more ridiculous requirements to keep them alive. I say let Darwin do his thing. :whistling
> 
> -Hal


Agreed.

If Darwin was right, how come there's still so many stupid people? :whistling


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## 91782 (Sep 6, 2012)

480sparky said:


> Nope. I didn't make any claims. So it's not up to me to prove anything.


Yes you did.
you gonna challenge - YOU provide the evidence.

Oh wait - you misplaced your code book - my bad.


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## Fouthgeneration (Jan 7, 2014)

See - 210.21 Outlet Devices.
- - (B) Receptacles.
- - - (3) Receptacle Ratings. Where connected to a branch circuit supplying two or more receptacles or outlets, receptacle ratings shall conform to the values listed in Table 210.21(B)(3), or where larger than 50 amperes, the receptacle rating shall not be less than the branch-circuit rating.
- - - - Table 210.21(B)(3) Receptacle Ratings for Various Size Circuits (Jerry's note: This states 15 amp receptacle on a 15 amp circuit or a 15 amp receptacle on a 20 amp circuit, *but not* a 20 amp receptacle on a 15 amp circuit.)




That is supposed to be a link to an image of the table of permitted ratings v CB amps.

And to think I was confused about pass through vs. face plate ampacity......


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## C'est Moi (Jun 6, 2015)

I agree with 4th gen--- Table 210.21(B)(3) is clear that a 15 amp circuit cannot be connected to a 20 amp circuit.

I also would not recommend a multiwire branch circuit anymore in a residence with afci requirements and now with gfci requirements for dishwashers.

If you run a multiwire branch circuit for a disposal and dishwasher you would have to install a gfci in a readily accessible location for the dishwasher.


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## C'est Moi (Jun 6, 2015)

Leo G said:


> They made a code that you can't put a panel box within 3 feet of a window because some stupid person reached in a window and killed himself off because he reached into the open panel.
> 
> That's a stupid code.


I assume that is a local code because it is not an NEC code


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## Fouthgeneration (Jan 7, 2014)

Not installing separate circuits and dedicated outlet fixtures, (every duplex outlet providing an outlet for low Ampere low use appliances)

is silly. As inverters and variable frequency digital drives become evermore common and "pollute" the their circuits with harmful voltage spikes/noise.

The code is a GUIDE for MINIMUM qualities and amounts, any structure that isn't a flop house or pre- engineered metal building should exceed them in a rational market place. IMHO:blink:

Yugos were legal, but would you let your only daughter drive/own one?:jester:


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## tjbnwi (Feb 24, 2009)

Fouthgeneration said:


> Not installing separate circuits and dedicated outlet fixtures, (every duplex outlet providing an outlet for low Ampere low use appliances)
> 
> is silly. As inverters and variable frequency digital drives become evermore common and "pollute" the their circuits with harmful voltage spikes/noise.
> 
> ...


The manufacturers installation instructions are the guiding documents. The NEC states you have to install per manufactures instructions. Most "permanently" installed require a separate circuit. 

On the Yugo question--sure why not. By now I would have taken care of any issues. 

Tom


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## C'est Moi (Jun 6, 2015)

Some appliance mfg. recommend a separate circuit so that does not require a separate circuit. I do agree that most of them do state separate circuit.


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## tjbnwi (Feb 24, 2009)

C'est Moi said:


> Some appliance mfg. recommend a separate circuit so that does not require a separate circuit. I do agree that most of them do state separate circuit.


I'm having a hard time understanding your response. 

Separate circuit or not if the manufacture installation documents state separate circuit?

Tom


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## C'est Moi (Jun 6, 2015)

I am saying that if the mfg company recommends a separate cirxuit then that is not the same as the mfg company requiring a separate circuit.

One is a requirement and the other is a recommendation and as such we do not have to follow it.


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## tjbnwi (Feb 24, 2009)

C'est Moi said:


> I am saying that if the mfg company recommends a separate cirxuit then that is not the same as the mfg company requiring a separate circuit.
> 
> One is a requirement and the other is a recommendation and as such we do not have to follow it.


Okay. Don't recall ever seeing one that "recommended" a separate circuit. If they mention it at all it's been in the "electrical requirement" section. 

I will pay closer attention on the next few installs. 

Tom


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## Irishslave (Jun 20, 2010)

Anyways job was completed last week 5 devices (outlets) 4 home runs other than pulling the 200+ foot of NMB.....piece of cake.....no garbage grinder...no DW....homeowner wanted neither


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## Leo G (May 12, 2005)

I don't have either of those. My dishwasher cleans the house, cooks me dinner, makes my lunch and does the laundry.


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## Inner10 (Mar 12, 2009)

Leo G said:


> I don't have either of those. My dishwasher cleans the house, cooks me dinner, makes my lunch and does the laundry.


I thought she only packed you lunch on Fridays?

Sent from my Nexus 6P using Tapatalk


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## Leo G (May 12, 2005)

Friday is Tuna day. Thursday is chicken salad day. Mon-Wed is deli day.

She loves me all week.


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## Hotneutral (May 17, 2017)

Appliances that consume half the ampacity of the circuit must be dedicated. If a diswasher uses 10.01 amps on a 20 amp circuit it must be a dedicated circuit. Likewise with disposals. Most are close enough to warrant wiring a dedicated circuit. Allowance for future appliance upgrade should be considered as well. I?ve never heard about the window rule for panels but considering the fact that most windows have a sill if the pane is three feet away then the sill is less which violates nec requiring panels to have 3 feet of clearance at minimum. More in some cases. I?m in the US so Canadian, European, etc. codes may vary on this I do not know.


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