Yes they are accessible to the pilots. Maintenance also use them to isolate or remove power in order to perform maintenance tasks/make systems inop while aircraft is in hangar undergoing routine maintenance to prevent systems from activating while working on other systems that are incorporated in the whole aircraft.Excellent example of a breaker's superiority to a fuse in a specific application! Not sure if these are accessible to the pilots but, on the surface, finding the right fuse at 30k feet in a stressful situation might be a tad difficult!
Great thread and invaluable input on this!I'm currently rebuilding my 1fz-fe, and tidying up my engine bay and accessory wiring while the engine is out.
PO has replaced the main 100amp fusible link with a 100amp maxi-blade fuse in an inline fuse holder.
Its been kind of poorly done and I want to remove it. I accidentally shorted battery cables while working on stuff, and popped this fuse.
I tried several spares shops for replacement fuse, and had to order spares in (not great if a fuse blows in the back of nowhere(
I've got OEM fusible links on backorder with Toyota Japan. The 6-8week delay in sourcing replacements has me thinking about replacing all the fusible links with circuit breakers at the battery.
I know enough about them to make myself look silly. So I'm looking for tips. I did search, found some helpful stuff, but nothing directly related to replacing fusible links.
Part of my thoughts is that having a breaker pop while on a trip, you give it time to cool down. Investigate for a problem that may have caused it to trip, and then if all good reset, and you're mobile again.
I believe there's different types of breakers, with some that cope with momentary spike in current. Beyond that, not really sure what else I need to know.
Is there any inherent disadvantages of circuit breakers that would rule this out as a feasible solution?
I know initial cost is gonna be a lot higher than using fusible links. I'm more interested in a foolproof solution that isn't relying on me carrying spare fusible links, or having to do a trail repair on a blown link?
Fuses are just as susceptible to heat or heat soak as a breaker. Modern fuses and breakers have current limiting (from faults and shorts) as well as overload capabilities. When looking at overload protection, both overcurrent protective devices (OCPD) rely on the temperature the device "sees". The warmer the environment they are in, the earlier they will trip or fuse. This must be accounted for in the design. The problem both suffer is the extreme temperatures they are installed in.Great thread and invaluable input on this!
My only thing would be going back to the reasoning that the factory FL's are not satisfactory in the first place.
If it's because they are failing in an otherwise factory environment, then obviously a thorough look-see-hunt-down for the cause is required.
As others mentioned and I agree, FLs are the most compact and efficient device for the purpose.
Carry 4 of them if you're that concerned. Especially with that brand new sweet-running engine you got there.
If you want a fuse but not a FL, MRBFs would be the next most efficient and compact alternative to FLs. (but not cheap. Or ubiquitous)
Otherwise, 'all I got' for the FL team is that breakers can heat soak, and I haven't seen a fusible link or fuse do the same.
full disclosure - all 3 are deployed in my rig - OEM FL, MRBFs, and breakers.