Is it a code violation to have the garbage disposal and the dishwasher fed from a 4 wire feeder, with a common ground and neutral? They are each on their own breaker? All are #12 AWG. The 4 wire feeder is connected to dual receptacle box under the kitchen sink.
If the breakers are on the same phase, the neutral currents from each appliance will add together. Depending upon the load connected, the neutral current can sum to double the current on the phase legs.
I note:
The 4 wire feeder is connected to dual receptacle box under the kitchen sink.