My question refers to a 120/240 VAC Single phase panel. The kitchen circuits would be the 2 small appliance circuits that require GFCI protection above the countertops and then a feed with the 3rd ungrounded conductor to the cord connected garbage disposal. I'm just wondering where you draw the line on sharing the neutral since the receptacles would be getting use by small appliances (with motors) and the garbage disposal alone can pull up to 7 to 10 amps. What is the general rule of thumb to make sure if you run multiwire branch ciruits to different parts of a house that you do not risk a fire by overloading the neutral. Lets say one receptacle has a toaster plugged in and it is running at 10 amps and then a blender is running at 2 amps and then the garbage disposal gets turned on (another 10 amps). Well the circuit breakers are not going to trip because you have not exceeded the maximum amperage on each ungrounded conductor. But is the neutral then carrying a total of 22 amps?
