I have a 8-place Square D subpanel with a 70A switch and a 30A breaker wired with one of those mechanical interlocks that prevent both from being on at the same time.
So I'll run the 30A breaker via 10/4 romex to an outside plug, which is where I'll connect my approx 5500W portable generator.
Then I'll run the 70A switch (2 hots) and a neutral via some 6ga wire in a conduit to a 60A 2-pole breaker in my main panel. Including a 8ga ground in the same conduit, being sure that the ground and neutral are not tied together in the sub-panel.
Then I'll load the remaining 4 spots in the subpanel up with the QOT tandem breakers. One of these is for a 240 circuit (water pump), and i'll tie two adjacent breakers together with a tie pin from Square D to make a 2-pole breaker. This leaves 6 circuits for 120V service.
Two things I want to make sure about:
If I add all the breakers in the subpanel up, I'll have 70A (2x20, 2x15) per leg, which exceeds the 60A subpanel feed breaker and certainly the 30A generator feed breaker, and even more so, the 5500W generator capacity. But I don't think the feed breaker will ever trip, and I'll just have to be careful when on genny. Is there anything not kosher about this setup?
I need to transfer a handful of circuits from the main panel to the sub panel. Can I do this the easy way.. by leaving each circuit run in the main panel, and splicing the hots ONLY with a wire nut to feed to the subpanel via wire of the appropriate guage in a conduit? Anything to be aware of here, especially if it is OK to leave the ground and neutrual for these transferred circuits terminated in the main panel? I could run those to, but not if I don't need to...