Originally Posted by Tool Junkie
If you havnt run the cable yet you can run a 3 wire cable and share the netural. Keep in mind the the breakers need to be next to each other so you can connect the switches together (via the holes on the breakers handles) as if one trips it is required (code) that they both trip.
Interesting and very helpful info!
I have a situation where previous owner used 12/3 BX into an outlet box, then ran another circuit from there upstairs. Share same neutral, but the breakers, although next to each other are not bonded.
Makes lots of sense to have breakers trip together for safety, but as I understand, as long as the breakers are next to each other (on opposite sides of the 220V line) there is no problem sharing the neutral, as the net current in the neutral wire is (theoretically) the difference between the circuits, not the sum. Would be a problem if one of the breakers is GFCI though!!