2 circuits sharing neutral
We had an electrician install 4 separate circuits (as per contract) for our kitchen remodel. Wires were brought from the service panel into a junction box under kitchen floor and from there went their separate ways to feed future (1) built-in microwave; (2) dishwasher; (3) garbage disposal; (4) one of the kitchen counter outlet circuits. Yesterday I noticed that in the service panel only 3 white (neutral) wires are coming in from that junction box while 4 red (hot) wires are connected to circuit breakers. A closer look at the junction box connections revealed that (3) and (4) share neutral taking it back to service panel... I hate surprises like that and will talk to the electrician but wanted to ask you all - is this "kosher"? Is this safe? I understand that garbage disposal is in use intermittently but still GD has 4-6 AMPacity. All new circuits are 12 AWG and 20 AMP breakers. Thanks!