Originally Posted by hellothere123
Sorry for asking a newbie question, I just want to make sure I do work in the panel correctly.
So I'd basically have 1 conductor running to the breaker...with the other end of that conductor connecting to the 2 conductors that go to the outlet and the dishwasher.
Is that the idea?
Depends on how "right" you want to do it.
1) NEC 110.3(B) incorporates the manufacturer's installation instructions, which supersede any more lenient provisions of the code.
So, strictly speaking, if the manufacturer specifies a dedicated circuit for the DW, that's what is required, per the NEC. (When this gets discussed on electrical discussion groups, some commentators note that the manufacturer's requirement is likely present to reduce liability rather than for more practical reasons, but in the end agree that this is the way the NEC is written.)
This prohibition is the first reason you "cannot" just tap some other, lightly loaded, circuit to power the DW.
2) Never the less, some local code authorities will allow a dishwasher and disposal on the same circuit, usually citing as 210.23(A)(2) as allowing this use. (Many others will not allow both loads to share this circuit, and require a dedicated circuit for the DW).
your AHJ allows this, you could power the DW off an existing 20A circuit serving only a disposal, however
you need to be aware that some disposals impose a load of 11A or more, so a DW and disposal on the same circuit can exceed the circuit's allowable total load.
3) The NEC prohibits powering either the DW or the disposal from the kitchen small appliance (counter) circuits, so you cannot
tap those circuits for the DW and any point along their length.
4) What about other circuits?
I'm not aware of any AHJ in my area that allows this. If they did, other provisions (for example NEC 210.23(A)(2)) would apply, and would likely prohibit attachment of a DW to many circuits.
So the bottom line is: check with your local AHJ, however be prepared to discover that powering a DW off any existing circuit (other than perhaps a dedicated 20A disposal circuit) is likely prohibited.