Free breaker lesson.
Terminology - Breakers are; open, closed, or tripped, never “on or off”.
They do not know if they are “powered” on not.
By design breakers are only good for one full rating trip.
After that the breaker is considered out of spec.
This usually melts the contacts or weakens the bimetallic in the breaker.
A therman overload, as this was, is a time based trip depending on the overload severity. Resetting the breaker just shortens the trip time by how cool it got while tripped. I have seen them trip and rest so often the literally blow up in hand while being reset.
So a breaker trips faster the more loaded it is, or has been.
As a note, most breakers can begin to start their timed trip at 80% of rating. So a 30A breaker could start it’s count down at 24A, but it might take a week to trip.
This is too allow for manufacturing tolerances. Two identical 30A breakers each with it’s own trip rating.
A resistive load, hair dryers, lights, etc. can creep up on a breakers rating closely. But an inductive load; A/C unit or fridge will spike the current 6-8 times running current at starting up. The breaker will allow for this short duration spike, as it is usually much less than a second, then cool down.
So if able, start the inductive loads first, then resistive.
If a breaker trips on a short circuit it is considered dead by the professional industry, but not local electricians. On a short circuit, current, (100-1000 times), is so high it blows the contacts in the breaker apart magnetically. The main job of the breaker then is; extinguish the electrical arc, keep itself together mechanically.
The small breakers on boats are fairly robust, they see little current cause the boat electrical system is relatively small and contained. The only place you have real destructive power is electrically near the genset and shore power.
The genset running can generate a tremendous amount of magnetic power, and the pedestal has the power company behind it.
As a note, always protect your genset first with fuses versus breakers. Fuses should be specially rated and very fast acting, and will protect the generator wiring and insulation from getting hot. You typically will not get these fuses without special ordering them. Same for battery chargers and inverters.
It is better to suffer with no A/C than buy a new generator winding.