Fuses or breakers?
There appear to be some very obvious places where there is no question which to use, like you want a breaker on an outlet that can easily have something plug into, and that thing could be too big a load, or shorted.
But what about the places where there really should never be an overload, unless there is something wrong? You really don't want a failing piece of electronics cycling on an auto reset breaker, and a manual reset breaker can be just as hard to get at as a fuse in many cases. Breakers can also age and fail, and some tend to generate heat. From what I have read, breakers of moderate cost still have some accuracy of trip issues. Fuses also have some heat issues, can get corrosion on the connections, and are a PITA to change and haul around spares.
I am looking at all the parts I might need to do the upgrade to a single battery bank in the place that the generator used to sit, and circuit protection is one of the things that will change to new parts do to increased charging rates. Right now it looks like I will need 6 good sized protection devices, either fuses or breakers.
300 amps right after the engine alternator
Two 120 amp, one each end of each of the two 4ga wires from the separator to the coach batteries--total 4 identical pieces
300 amps between the battery bank and charger/inverter
These are pretty big for DC breakers, fairly spendy, fairly large mounting area, and sized this way should never trip, so I am tempted to go with fuses. It would take less critical space, be substantially less expensive, should give more accurate trip, etc, as long as they can be placed in an easily accessible place. Our current system has a mixture of fuses and breakers on the similar locations, and we have never had any of them trip in 3 years of use.
What would you all use?