The provisions of the code are just the minimum requirements for safety and overthinking/ worry on the details of the code provision gets you nowhere, IMO. You could have been missing the forest for the trees there!I think I understand now what to do for this.. I found this snippet from Generac:
NEC 430.62 requires that the protective device be sized per 430.52 which limits the maximum inverse time breaker size to 250% of the motors nameplate rating. This sets the maximum size of the breaker. What about the minimum size of the breaker? What does “provide short circuit protection only” mean? NEC provides for short circuit, ground fault, and overload protection. Thus, short circuit only protection means no protection against ground fault or overload. NEC 430.32 defines overload protection at a maximum of 125% of the motor nameplate rating. Breakers sized larger than 125% provide no overload protection and thus provide short circuit only protection. The result of all this is that any breakers from the on-site generator source to the fire pump must be sized greater than 125% and less than 250% of the fire pump rating and support the temporary locked rotor amps associated with normal starting.