I have a simple eaton spa panel with a 240 50A GFCI breaker. As soon as I plug it in or flip the main breaker it trips. I followed one of P-J's spa panel diagrams and have it wired like this:
I did check for shorts with my multi-meter, and there were no faults between the neutral and ground and the hots. I did notice a slight buzzing when I touched the two hots on the output end of the breaker. Is that normal.