Greg:
Two comments for you from two different utility co's up here.
Pot two houses down block from home has a trip/reset hamdle on the side for the 120/240 secondary; it was reset many times due to overload until they replaced the 25KVA with a 50KVA. (12 homes load, summer time) It was reduced to 10 homes when they redid the block and added a additional pot.
Up where I work, the troubleshooters carry 5-10-15 & 25 rated fuses for the primaries; I do not know any info, but when I catch up with my 'go-to' shooter I'll chat with him.
Stay safe
