The problem as I see it is that Boeing designed the Backup Battery systems to take on other tasks. That means it will be connected in the distributed system and any problem becomes a systems problem, a 'systemic' problem.
Talk of "isolation" should have stopped with the "Backup Function". If the breakers that remove the Backup system from the distributed system are within the Batteries' enclosure, how is that a dependable "open"?
The switching is remote from the Batteries' case, right?
SoS... There is your "Fusible Link", eh? That is battery #6 @ #5? Let's hope that was not the source of the Captain's "Zero Voltage"....Hopefully the breaker tripped prior?
Last edited by Lyman; 15th Feb 2013 at 12:48.