For those reading this thread who are not familiar with the 7355 power center that donabstron has, it is a combination of 120 volt power center and 12 volt
converter/charger with all the 12 volt
fuses. There are two sections to it, 120 and 12 volt sides.
The problem appears to be on the 120 volt side and sounds like major damage has been already done to the AC lines from the 120 volt CB to the AC itself. I would guess that the 120 volt side of the unit will need to be replaced and that may involve the entire 7355 system as it may have enough damage so it is not really repairable. I don't know if the 120 volt side comes out like the 12 volt parts do. I just replaced the converter/charger and 12 volt fuse block in mine two days ago, upgrading to a 3 stage charger by Progressive Dynamics. (2014, FC 20' 3 weeks old)
Since it is a 2012 unit, this seems to be a Warrantee issue that Airstream needs to deal with, not something I would tackle on my own, if it was my rig. I would guess that someone has not tightened up the wires into and out of the 120 volt side of the power center. I had a failure like that once in my AS 310 motorhome, fried all the wires in the CB box which fed the AC unit, as well as the CB itself. Was a result of a loose connection to the CB, overheating the wire feeding the AC.