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Dishwasher circuit

8K views 18 replies 9 participants last post by  theatretch85 
#1 ·
Just wondering what is typical for new dishwashers these days. Will a single 15 amp circuit do or should I go with a 20 amp or even higher?

Also is there anything wrong with making the dishwasher a plugin? Normally they are hard wired, but it's easier to install if it's made to plug in. I have to run a circuit while someone else will install the dishwasher, so I want to ensure it's ready to go and to code. Installing a plug just seems cleaner, but guess it wont matter since I won't see it after anyway. :p
 
#3 ·
Manufacturers often specify what size circuit to put it on, but you can't go wrong by pulling 12-2. You can pick the breaker size and receptacle rating when you get the dishwasher. If you do use a cord, make sure it is listed as an appliance cord, and of course, make the plug easily accessible. And it will be no more than 20 A, unless you got some industrial Tim Taylor-sized unit.
 
#4 ·
As In Phase stated; Make sure the plug is readily accessible.
In my installation, the DW wiring runs down to the basement into a J-box.
I don't think I could have used a plug if I had wanted to, because the wiring runs through the floor.

To use a cord & plug for an appliance, it is my understanding that the receptacle must be located in the same space that the appliance occupies; the cord cannot go through a floor, wall, or ceiling to reach the receptacle.
I'm not sure about going from one under-cabinet compartment to another, such as from the DW area into the area under the sink.

That said, my gas oven is installed under a cabinet, and plugged into a receptacle in the back of the compartment. This plug/receptacle is not readily accessible, as the oven must be removed to gain access. I do not know whether this violates code or not. I did not do the install.

I also agree with In Phase on the wire size to pull. I don't think any residential DW will require more than a 20A line.
I would make this a dedicated line.

FW
 
#5 ·
keep in mind that the wiring and water supply must enter the DW area a certain minimum distance from the floor and distance out from the back wall. make sure you leave enough slack so that you can pull the DW out a bit and tighten up the water supply if it is leaking...

the best place to get an idea for how to install electrical, and what options are acceptable is to read the installation manual that comes with the DW you purchase. it will tell you all the above mentioned rules including if it is allowed to take electrical to different under-cabinet area (say under the kitchen sink) and THEN plug it in, or drop to basement for hardwired. if you want to get a head start, goto the store and select the DW and ask to see the installation manual for that model (you don't have to purchase it straight away). or goto manufacturer's website and download the PDF of installation manual. then go do the work and buy when you're ready.

my DW was purchased last year (finally installed it only a few weeks ago..) and made by GE. it was 15A, hardwired.

Knucklez
 
#6 ·
The DW is ordered but I don't recall the exact model. I am pretty sure it is an Inquis though. I might call them up just to confirm the model and take a look at the specs.

For hard wired would there be anything wrong with me installing a receptacle downstairs (accessible as I will never finish the crawlspace ceiling) and then make it run a ~6' wire upwards? That way the wire can easily be shortened/lengthened without worry of making it too short in the future. Not that dishwashers get replaced very often, but may as well future proof this and also make it tidy.
 
#8 ·
Remember if you do not use a cord and plug, you must install a disconnect. From the disconnect, you will hard wire the DW. A good place for the disco or receptacle would be under the sink where its easy to access.

Some exceptions to this rule exist. Do not concern yourself with them.
 
#10 ·
I have never seen a dishwasher with a disconnect other than the breaker in the main panel. Every dishwasher I have seen has been hardwired in and usually shares a MWBC with the garbage disposal. Of course the garabage disposal I have seen both plugin and hardwired versions and always has a switch above the countertop.
 
#11 ·
This is due to the exceptions that J.V. posted. If an appliance meets certain conditions, its disconnect can be the breaker, but the breaker has to be capable of being locked in the off position. There are little metal clips that are made for most breakers that fit this purpose. Personally, I have never done it, not because of lack of knowledge in the code, but lack of enforcement:laughing:. I'm not one to condone knowingly violating the code, but this is one of those things way down on the list. If I'm giving advice, I would say, install a plug or local disconnect, or find the breaker lock.
 
#15 ·
from NEC 2008

422.31 Disconnection of Permanently Connected
Appliances.


(A) Rated at Not over 300 Volt-Amperes or 1⁄8 Horsepower.

For permanently connected appliances rated at not
over 300 volt-amperes or 1⁄8 hp, the branch-circuit overcurrent device shall be permitted to serve as the disconnecting means.
when i read this, i think my DW is not over 300V, so i can use the breaker panel as the ON/OFF. no mention of locking device requirement here (but probably elsewhere in NEC). doi understand this correct?
 
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