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Dishwasher and Garbage Disposal on Same Circuit

jar546

jar546

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Is it possible to install a dishwasher and garbage disposal and have them on the same circuit, on the same duplex receptacle with one single 20A circuit and be code compliant?

When is it?

When isn't it?
 
jwelectric said:
Maybe, what is the amperage of the appliances?
Click to expand...
You tell me please. That is why there are 2 questions.

How many electricians have complained the inspector made them run separate circuits? Who is right is dependent on more factors than amperage of appliances.
 
Seeing that both the dishwasher and the disposal are both fastened in place appliances and you are not supplying lighting units, cord-and-plug connected utilization equipment not fastened in place then 210.23(A)(1) and (2) would not apply.

So 210.19 and 210.20 would be the driving factor in determining the branch circuit load.

Since neither the disposal nor the dishwasher would be considered a continuous load the combination of the loads of the 2 appliances could not exceed 20 amps.

So for example you could have a 12 amp dishwasher and an 8 amp disposal on a single 20 amp branch circuit and be code compliant.

Many people want to apply the 50% rule in 210.23(A)(2) to this situation but that section would not apply.

Chris
 
I have a dumb question. What raider posted is from the NEC. Wouldn't the IRC be applicable here? If so, wouldn't E4101.4 apply which is why I believe jwelectric asked the amperage?
 
422.16 Flexible Cords.

(A) General. Flexible cord shall be permitted (1) for the connection of appliances to facilitate their frequent interchange or to prevent the transmission of noise or vibration or (2) to facilitate the removal or disconnection of appliances that are fastened in place, where the fastening means and mechanical connections are specifically designed to permit ready removal for maintenance or repair and the appliance is intended or identified for flexible cord connection.

(B) Specific Appliances.

(1) Electrically Operated Kitchen Waste Disposers. Electrically operated kitchen waste disposers shall be permitted to be cord-and-plug-connected with a flexible cord identified as suitable for the purpose in the installation instructions of the appliance manufacturer, where all of the following conditions are met: See related ROP UL

(1) The flexible cord shall be terminated with a grounding-type attachment plug.

Exception: A listed kitchen waste disposer distinctly marked to identify it as protected by a system of double insulation, or its equivalent, shall not be required to be terminated with a grounding-type attachment plug.

(2) The length of the cord shall not be less than 450 mm (18 in.) and not over 900 mm (36 in.).

(3) Receptacles shall be located to avoid physical damage to the flexible cord.

(4) The receptacle shall be accessible.

(2) Built-in Dishwashers and Trash Compactors. Built-in dishwashers and trash compactors shall be permitted to be cord-and-plug-connected with a flexible cord identified as suitable for the purpose in the installation instructions of the appliance manufacturer where all of the following conditions are met:

(1) The flexible cord shall be terminated with a grounding-type attachment plug.

Exception: A listed dishwasher or trash compactor distinctly marked to identify it as protected by a system of double insulation, or its equivalent, shall not be required to be terminated with a grounding-type attachment plug.

(2) The length of the cord shall be 0.9 m to 1.2 m (3 ft to 4 ft) measured from the face of the attachment plug to the plane of the rear of the appliance.

(3) Receptacles shall be located to avoid physical damage to the flexible cord.

(4) The receptacle shall be located in the space occupied by the appliance or adjacent thereto.

(5) The receptacle shall be accessible.
 
Codegeek said:
I have a dumb question. What raider posted is from the NEC. Wouldn't the IRC be applicable here? If so, wouldn't E4101.4 apply which is why I believe jwelectric asked the amperage?
Click to expand...
E4101.4 and 422.11(A) and (E) are basically the same requirement.

This section states that IF an OCPD rating is marked on the appliance then you must protect it with an OCPD that doesn't exceed that rating.

Chris
 
Gregg Harris said:
422.16 Flexible Cords. (A) General. Flexible cord shall be permitted (1) for the connection of appliances to facilitate their frequent interchange or to prevent the transmission of noise or vibration or (2) to facilitate the removal or disconnection of appliances that are fastened in place, where the fastening means and mechanical connections are specifically designed to permit ready removal for maintenance or repair and the appliance is intended or identified for flexible cord connection.

(B) Specific Appliances.

(1) Electrically Operated Kitchen Waste Disposers. Electrically operated kitchen waste disposers shall be permitted to be cord-and-plug-connected with a flexible cord identified as suitable for the purpose in the installation instructions of the appliance manufacturer, where all of the following conditions are met: See related ROP UL

(1) The flexible cord shall be terminated with a grounding-type attachment plug.

Exception: A listed kitchen waste disposer distinctly marked to identify it as protected by a system of double insulation, or its equivalent, shall not be required to be terminated with a grounding-type attachment plug.

(2) The length of the cord shall not be less than 450 mm (18 in.) and not over 900 mm (36 in.).

(3) Receptacles shall be located to avoid physical damage to the flexible cord.

(4) The receptacle shall be accessible.

(2) Built-in Dishwashers and Trash Compactors. Built-in dishwashers and trash compactors shall be permitted to be cord-and-plug-connected with a flexible cord identified as suitable for the purpose in the installation instructions of the appliance manufacturer where all of the following conditions are met:

(1) The flexible cord shall be terminated with a grounding-type attachment plug.

Exception: A listed dishwasher or trash compactor distinctly marked to identify it as protected by a system of double insulation, or its equivalent, shall not be required to be terminated with a grounding-type attachment plug.

(2) The length of the cord shall be 0.9 m to 1.2 m (3 ft to 4 ft) measured from the face of the attachment plug to the plane of the rear of the appliance.

(3) Receptacles shall be located to avoid physical damage to the flexible cord.

(4) The receptacle shall be located in the space occupied by the appliance or adjacent thereto.

(5) The receptacle shall be accessible.
Click to expand...
These sections apply to cord and plug connected appliances but does not address the size or rating of the branch circuit that they are connected to.

Chris
 
I asked the amperage of the two appliances because of this statement.

raider1 said:
Seeing that both the dishwasher and the disposal are both fastened in place appliances and you are not supplying lighting units, cord-and-plug connected utilization equipment not fastened in place then 210.23(A)(1) and (2) would not apply.So 210.19 and 210.20 would be the driving factor in determining the branch circuit load.

Since neither the disposal nor the dishwasher would be considered a continuous load the combination of the loads of the 2 appliances could not exceed 20 amps.

So for example you could have a 12 amp dishwasher and an 8 amp disposal on a single 20 amp branch circuit and be code compliant.

Many people want to apply the 50% rule in 210.23(A)(2) to this situation but that section would not apply.

Chris
Click to expand...
Chris, do you ever get a headache? you make mine hurt just watching that rock and roller
 
jwelectric said:
I asked the amperage of the two appliances because of this statement. Chris, do you ever get a headache? you make mine hurt just watching that rock and roller
Click to expand...
Now that I'm getting older my headbanging looks more like a seizure. Also my hair isn't as long or as thick. :D :D :D

Chris
 
I agree with Chris. If you install the disposal & dishwasher with even one light then the 50% rule comes in but not if there are just two motors. Besides the legality of it there would never be a situation where the disposal and dishwasher being on at the same time would blow the circuit unless someone left the disposal running. That would be a good thing if it did blow- IMO.. The disposal is often on for less than 10 secs and there is no way that will trip the overcurrent protective device.

A similar issue arises with garage doors. How many have seen two or three doors on the same circuit with the receptacles in the garage and on a 15 amp cir. Not compliant but I bet it would never be an issue.

I am not saying to ignore it but IMO, there should be some exception added. I have not figured out how to word it properly to make the proposal.
 
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