I think first off it is cheaper to build as a compact unit, secondly, it is easier (cheaper) to R/R as a unit and third, it conforms cleanly with the spirit of the FAA rule to isolate the pack (all of it) away from other EE equipment, in case of fire, expansive failure (explosion), electrolyte spatter, and draining thereof.
Y'all have done a great job of describing how better to build it. Know this, Boeing knows this as well. But they built it the way they built it.
The reason? Also an interesting discussion. For one thing, LRU....
Last edited by Lyman; 27th Jan 2013 at 22:36.