I had a spa panel installed when the home was built for a future spa. Now we've found a spa and it requires 60a breaker at the panel. The panel has a 50a breaker in it. The panel inside the house at the other end has a 60a breaker. The wire between the panels is 6 AWG copper. I've read 4 gauge wire would be better for the 60a but also that the 6 gauge wire is enough and is what is required per the spa manual. Can I just swap the 50a breaker for a 60 at the spa panel and not have to install 4 gauge wire and a 60a spa panel?
If it's a 50 AMP panel then you'll need to upgrade it to a 60 amp panel with a 60 AMP breaker. The #6cu is good for 65 AMPS so that will work. The #4cu would be a waste of money. You will need GFIC protection at one set of breakers.