dishwasher wiring residential homes

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mikie65

New member
does the electrical code still allow a 15 amp circuit to be used for a spec house dishwasher location? and why?
 

Jljohnson

Senior Member
Location
Colorado
Another example of wiring to code minimum perhaps being synonymous
with "poor design". I would never wire a DW with less than a 20 amp circuit personally. Please note that I did use the word "perhaps". This would mean that this is MY opinion.
Jim
 

iwire

Moderator
Staff member
Location
Massachusetts
Jim if you 'never wire a dishwasher with less than a 20 amp circuit' you may well have been in violation of 110.3(B) and 422.11(A).

Some dishwashers specify 15 amp circuits and that is not 15 amp minimum it is 15 amps period.

422.11 Overcurrent Protection.
Appliances shall be protected against overcurrent in accordance with 422.11(A) through (G) and 422.10.

(A) Branch-Circuit Overcurrent Protection. Branch circuits shall be protected in accordance with 240.4.

If a protective device rating is marked on an appliance, the branch-circuit overcurrent device rating shall not exceed the protective device rating marked on the appliance.

Minor issue but a code violation none the less.
 

infinity

Moderator
Staff member
Location
New Jersey
Occupation
Journeyman Electrician
Why is a dishwasher wiring residental homes in the first place? Shouldn't he be washing dishes? :lol:
 

aftershock

Senior Member
Location
Memphis, TN
You must also take into account the local codes.
I have to wire a 20 amp circuit for a dishwasher. And I am still allowed to have the dishwasher and disposal on the same circuit.
Since I have been reading these forum, I have see alot of things allowed in other areas that I am not allowed to do and vice versa.
I got turned down on an inspection once because I used a 40 amp breaker for a stove circuit. Go figure , AHJ wanted a 50 amp before he would pass it.
 

Jim W in Tampa

Senior Member
Location
Tampa Florida
I would wire it with #12 and then if needed put in a 15 amp breaker.With #14 your asking for a problem should the buyer or owner selects a different dish washer that needs the 20.Are we getting to cheap to use #12 ?
 

electricmanscott

Senior Member
Location
Boston, MA
Jljohnson said:
Another example of wiring to code minimum perhaps being synonymous
with "poor design". I would never wire a DW with less than a 20 amp circuit personally. Please note that I did use the word "perhaps". This would mean that this is MY opinion.
Jim

Understood, your "opinion". But why?
 

jeff43222

Senior Member
Does the NEC prohibit dishwashers and disposals on the same circuit? I usually put them on separate ones, but I don't know of anything that prohibits putting them on the same 20A circuit, assuming neither appliance pulls more than 10A.
 

Ragin Cajun

Senior Member
Location
Upstate S.C.
I do a lot of apartments. I call for a split receptacle under the sink, one side for the dishwasher, the other side for the disposal. Using SO cord to each appliance also provides for a convenient disconnect feature.

I use a 20A, two pole breaker to feed the split receptacle.
 

celtic

Senior Member
Location
NJ
infinity said:
Why is a dishwasher wiring residental homes in the first place? Shouldn't he be washing dishes? :lol:

Watch out !
brick.gif
 

jeff43222

Senior Member
Ragin Cajun said:
I do a lot of apartments. I call for a split receptacle under the sink, one side for the dishwasher, the other side for the disposal. Using SO cord to each appliance also provides for a convenient disconnect feature.

I use a 20A, two pole breaker to feed the split receptacle.

This is exactly what I do when circumstances permit. There are occasions where it's not feasible, though.
 

iwire

Moderator
Staff member
Location
Massachusetts
Rajun and Jeff again I point out

422.11 Overcurrent Protection.
Appliances shall be protected against overcurrent in accordance with 422.11(A) through (G) and 422.10.

(A) Branch-Circuit Overcurrent Protection. Branch circuits shall be protected in accordance with 240.4.

If a protective device rating is marked on an appliance, the branch-circuit overcurrent device rating shall not exceed the protective device rating marked on the appliance.

I doubt that you will find that dishwashers or disposals require a 20 amp circuit, there are DWs that are marked with 15 amp and feeding them with a 20 is a violation.
 

jeff43222

Senior Member
I think the key phrase here is "protective device rating." I also noticed that the code section says if such a rating is marked on the device, then it has to be followed. So if I look at a dishwasher's nameplate and see, for example, 9.6 amps, is that merely the rating of the dishwasher, or the "protective device rating" of it? That "if" makes me think it's not something that will always be on a nameplate.

On the more practical side, if I wire up a multiwire circuit/receptacle for the dishwasher and disposal, I often have no idea what the appliances are rated for when I do the wiring because the homeowner frequently doesn't decide on a specific model until later in the process. I don't think it will fly if I tell someone that I'm only going to install for 15A unless they prove to me that the appliances will allow a bigger circuit.

I've done these dual 20s for a while now, and none of the inspectors I've dealt with has ever said a word to me about it.
 
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