# Dishwasher And Garbage Disposal On Same Circuit?



## J F Go (Mar 1, 2014)

I've done it for many years without issue.


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## eddy current (Feb 28, 2009)

Does the NEC specify that a dishwasher must be on its own circuit?
Although it is commonly done that way, there is no code in the Canadian book that says it must be on its own circuit.


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## Dennis Alwon (May 9, 2009)

It probably is not compliant however most inspectors would not call it out simply because the disposal is on for seconds.

If you have a 20 amp circuit and the dishwasher is 10 amps or more than this section comes into play



> 210.23(A)(2) Utilization Equipment Fastened in Place. The total rating
> of utilization equipment fastened in place, other than luminaires,
> shall not exceed 50 percent of the branch-circuit ampere
> rating where lighting units, cord-and-plug-connected utilization
> equipment not fastened in place, or both, are also supplied.


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## Dennis Alwon (May 9, 2009)

I actual read that section differently. I think there is no issue with 2 motors as long as their combined amp is not more than the 20 amp circuit


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## splatz (May 23, 2015)

Dennis Alwon said:


> I actual read that section differently. I think there is no issue with 2 motors as long as their combined amp is not more than the 20 amp circuit


The issue could be if one or the other was cord and plug connected.


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## samgregger (Jan 23, 2013)

Both my disposal and dish washer fastened in place.


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## Dennis Alwon (May 9, 2009)

samgregger said:


> Both my disposal and dish washer fastened in place.


Of course.. but I see the dishwasher and disposal as 2 motors. 

If the dishwasher is 12 amps and the disposal 6 amps then 12 x 1.25= 15 amps + 6 amps = 21 amps. That would be a technical violation however you would never ever overload the circuit simply because the load would be under 20 amps. Even if it were a tad over it would take a long time to heat up a breaker enough to trip.


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## samgregger (Jan 23, 2013)

How about put the disposal and dishwasher on a 3-way? That way you can't run them at the same time, like a cheap circuit ampacity interlock.


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## Dennis Alwon (May 9, 2009)

samgregger said:


> How about put the disposal and dishwasher on a 3-way? That way you can't run them at the same time, like a cheap circuit ampacity interlock.



I believe that would work if the switch were not considered a disconnect


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## former farmer (Feb 27, 2013)

samgregger said:


> How about put the disposal and dishwasher on a 3-way? That way you can't run them at the same time, like a cheap circuit ampacity interlock.


Then you'll have to expain to the homeowner why their dishwasher quits working when they use the garbage disposal. I could see that being a headache from an electrical support aspect.


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## splatz (May 23, 2015)

former farmer said:


> Then you'll have to expain to the homeowner why their dishwasher quits working when they use the garbage disposal. I could see that being a headache from an electrical support aspect.


Do all dishwashers recover gracefully if you pull the power for a few seconds in the middle of a cycle? I never really thought about it, what do they do if power blips during a storm?


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## Dennis Alwon (May 9, 2009)

splatz said:


> Do all dishwashers recover gracefully if you pull the power for a few seconds in the middle of a cycle? I never really thought about it, what do they do if power blips during a storm?


There would never be a need to do that as it would take the breaker at least 30 seconds or more to trip on that overload


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## splatz (May 23, 2015)

Dennis Alwon said:


> There would never be a need to do that as it would take the breaker at least 30 seconds or more to trip on that overload


I meant with the switch, like @samgregger 's suggestion.


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## Dennis Alwon (May 9, 2009)

splatz said:


> I meant with the switch, like @samgregger 's suggestion.



Got it... In response to your other question I don't know about turning power off to the dishwasher but just opening the door doesn't seem to affect the cycle. Dropping power to the unit may kill the cycle--IDK


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## kb1jb1 (Nov 11, 2017)

This same dilemma exists with some laundry washers and gas dryers. NEC only requires one 20 amp laundry circuit. I have seen many electricians run the one circuit and put several receptacles on it. One for the washer and the other for the gas dryer. Some share a 20 amp duplex for both washer and dryer. The high end washers use 10.3 amps and the high end steam gas dryers use 12.6 amps. Now you have 23 amps on a 20 amp circuit. Is the washer permanently installed? Is the gas dryer permanently installed? Will this work? IDK. I gave up trying to figure out what others do because the NEC is not followed by many.


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