This subject must have been around here before; I thought I saw what Don referenced above, but could not find any written word. Bob's mention of 310.15 not being an 'ampacity chart' was debated at length locally, and the ampacities listed are to be considered 'code' for resi work.
As I said, no one has attempted this in my area.
As to using multiple conduits....my only way as an EC.
John
