Can I run 12/3 across a garage, overhead to a basement, and then use this shared neutral to feed 2 GFI proctected dircuits? Pigtail the neutral to go to each separate circuit - each having 2-3 outlets - unknown and variable loads - depending on homeowner.
Breaker will be a 2 pole 20 - yoked - common trip.
Each GFI will compare incoming - red or black - with neutral, and will be independant of the load on the other red or black feed. Right?
So if the load on the black is 6A and the load on the red is 10A what happens? In this case, does the GFI device look only "downstream", or does it look "upstream" as well - that is, does it see the imbalance at the pigtail, or only on the load side of the device?
Or do I need a 2 pole GFI breaker?