That idea came from my neighbor. I am still not sure what he is going to do.
BTW Dale Electric has a Siemens 60a transfer panel on sale for $44. I looked at it but I still can't figure out how I could wire it up in my situation. I would certainly be looking at that same situation of multiple circuits/feeders between buildings. It would even be harder for me than the neighbor. I would probably end up with 2 transfer panels and having to bury another feeder out to the garage. Suppose I could sneak a couple #10s in the current raceway with the house feeder from the generator but that would open another question. Would you have to derate?
It is a non-coincidental load.
