[tStano]

Yes. That is a real problem, and be sure that what you plug into a 30 amp slot doesn't draw more than 30 amps (at least for any sustained amount of time). They're thermal circuit breakers, so for short time periods(start-up), you can pull more than the number on them. The main breaker's a thermal circuit breaker too.

But as long as you don't run all your motors at once, especially near the end of the match, you should be fine for main breaker tripping and brownouts. Batteries also have limited energy stored in them, but that doesn't become a huge issue unless the motors have lots of load on them and/or you are running many of them a great percentage of the time.

As I understand it, you also aren't really running out of slots, just 40 amp slots. Good luck!