Electrical - Dishwasher hookup.

Discussion in 'Electrical Forum discussion & Blog' started by bjferri, Jul 14, 2010.

  1. ss3964spd

    ss3964spd New Member

    Messages:
    41
    Hi all, am reviving this old thread since it pertains to exactly what I am doing.

    If I am reading it correctly it is permissible to connect a DW via a correctly sized cord with a plug, and plug it into an outlet in an adjacent cabinet - in this case the sink base, or in an outlet mounted in the wall with the rear of the cabinet cut out for access to the outlet.

    If I chose to surface mount a box to the inside of the cabinet is it permissible to simply bring the feed wire through a hole in the drywall and cooresponding hole in the cabinet (this seems like an inelegant way of doing things).

    Same question pertains to the garbage disposal - can I also connect it to an outlet via cord and plug, or must it be hard wired?

    Finally, must the dishwasher and disposal be on completely seperate circuits?

    Many thanks,

    Dan
  2. jwelectric

    jwelectric Electrical Contractor/Instructor

    Messages:
    2,560
    Location:
    North Carolina
    Yes
    Yes
    Maybe but most likely yes
  3. ss3964spd

    ss3964spd New Member

    Messages:
    41
    Many thanks!

    Dan
  4. Chad Schloss

    Chad Schloss Member

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    330
    Location:
    USA
    Can you have a dishwasher hardwired, but then have the 14/2 for the d/w run to a junction box, say in a crawlspace or basement, where it then ties into a short cord to be plugged into a receptacle (under the sink, for means of disconnecting)?
  5. Homeownerinburb

    Homeownerinburb New Member

    Messages:
    525
    Location:
    Los Angeles, CA USA

    I cannot for the life of me imagine why one would. I cannot cite the code restriction, but I am as certain as I can be that one cannot have a cord disappear into a wall or a floor.

    Why not just run MC from the DW to a switch box in the sink cabinet?
  6. ss3964spd

    ss3964spd New Member

    Messages:
    41
    Thanks for the additional replies.

    One of the reasons for the ask is that this DW, a Bosch unit, has the electrical connection at the bottom front of the unit and the feed then runs down, under, and back through a channel in the bottom of the enclosure (ditto with the water line - but through it's own channel). The J-box at the bottom front is extremely small and trying to stuff 12 or 14/2 into it is no picnic. Using a cord/plug would allow me to wire into the J-box with more flexible wire, lay the wire into the channel, feed the electrical, water, and drain lines throught the sink base cab.

    Anyway, I've got it squared away - terminated a dedicated circuit in a wall box with a duplex receptacle within the sink base cabinet. I have a second dedicated circuit in the same box for the garbage disposal. Had I thought it out a little more I could have gotten away with one receptacle for both but as it now stands only one outlet on each is live.

    Dan
  7. Homeownerinburb

    Homeownerinburb New Member

    Messages:
    525
    Location:
    Los Angeles, CA USA
    Not to be pedantic or make you miserable, but:

    A dedicated circuit for a single appliance is supposed to end in a single outlet, not a duplex.

    As you describe, you could have had a duplex with the two receptacles used for the two circuits.

    In that event, it is required that they be feed in common by a two pole breaker, such that if one circuit trips, both will go cold. I really need to retrofit the one in my kitchen.....

    And of course one uses one neutral conductor, as the two circuits will be at opposite ends of the phase. One does not use one length of NM to bring one hot and one neutral and another to bring another neutral.

    This gets so very complicated......you have only violated a small item in the code (using two duplex outlets to terminate two dedicated circuits), there are aspects of the code that are harder to explain than others. This might be one of them.
  8. ss3964spd

    ss3964spd New Member

    Messages:
    41
    No worries, Burb, I like to learn and do things as correctly as I can.

    Maybe my explanation wasn't clear. I have two completely seperate circuits, both feeding into a single 2 gang box. Although I used two duplex receptacles I broke off the connecting tabs on each side of both receptacles, effectively rendering them (in my mind anyway) 4 single receptacles. The DW circuit is connected to the top of the duplex, the bottom is dead. Same for the BD. Once the DW and GD are plugged into their dedicated receptacle I didn't want anyone to plug anything else in so the others are dead. The only thing common is the 4 gang box. Does this arrangement seem sound or is it still a little wonky?

    What I meant by "I could have gotten away with one receptacle for both" was I thought I could have broken the side tabs off one duplex receptacle and wired one circuit to the top and the other to the bottom. I'd still have two separate, dedicated, circuits, sharing only the plastic body of the duplex receptacle.

    Dan
  9. Homeownerinburb

    Homeownerinburb New Member

    Messages:
    525
    Location:
    Los Angeles, CA USA
    What you have done is extremely dangerous.

    You have a duplex receptacle, two in fact, where half of the receptacle is unpowered.

    A repairman could easily get under there and think he has turned the power off and not actually have done so.

    You should reverse what you did. To be fully to code, replace the two duplex receptacles with single receptacles. If you just want to use duplexes, that would be much safer than what you did.

    Or change it to one duplex with two hots, opposite sides of the phase, fed by a two pole breaker.

    If the neutrals for the two hots are taking different routes (not a shared three-wire circuit) then break the tab on the neutral side as well and be VERY aware of which neutral goes with which hot. I'd tape them together a few inches behind the receptacle, color coded.

    The first solution is the best, considering that you have a two gang box. Getting a faceplate to suit might be a pain in the back side.
    Last edited: Jun 26, 2012
  10. ss3964spd

    ss3964spd New Member

    Messages:
    41
    Thank you for that insight. I always build/work to code (which is why I wanted to bounce this off the folks here) but since I do all my own work I often forget that eventually someone other than me might end up having to deal with something.

    Thanks Burb, I'll go back and make it right.

    Dan
  11. Homeownerinburb

    Homeownerinburb New Member

    Messages:
    525
    Location:
    Los Angeles, CA USA
    Yes, one of the reasons for building a code and sticking to it would be to work to a common minimum standard of safety. If I walk into your house twenty years from now after you have sold it, I should hope to find certain arrangements to be in place, and if I don't find them, I should take it as a clue that something is amiss and needs investigation.
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