Exemplary 2 Circuits In One Box
American electrical advice forum.
2 circuits in one box. 1 of 3 go to page. Discuss can you have two separate circuits in one box junction box. Other than that you can have as many circuits as you have devices in the box as long as you have adequate room in the box for splices and connections.
As stated in this question if the junction box has the required cubic inches for the wiring that will be installed then yes it is acceptable to have more than one circuit in the same electrical box or junction box. Discuss can you have two separate circuits in one box junction box. So for your examples.
American electrical advice forum. 1 totally normal and 2 yes you re running 12 3 for a multiwire circuit where your dishwasher and disposer share the neutral conductor in the 12 3 cable. So two circuits require a double pole breaker or two single pole breakers with handles.