5000W Generator backup for a house, 20A 120/240 output
Tranfer Switch is 2 30A breakers
I'm using #10 (20A X 1.25) ? for all feeders
Should breaker from main panel be 30A, or 20A?

I used 30A in the past (cause I was told to), but with a 20A output from the Generator, I'm second guessing. Maybe I'm missing a rule or something.

What do yalls think?