I would unplug the ozone, unplug the topside and blow it out, leave the ozone unplugged and give it a try.
if you have a Circ pump it could have gotten wet so you might unplug that and see if the 30 amp would reset.
Does this spa have a blower? That is another potential. Often I have people in remote areas unplug components one at a time and then reset. Always replug what you've already tried before unplugging the next.
I also thought the heater was on the 30 amp.... often when you drain and refill a spa you can cause a "dry fire" in the heater and have a failure.
If you shut off power and open the box you can trace the wires to see where they go.
Once you've located components than just (with power off) unplug, reset breaker and keep going through one at a time until you find the error.