Are you still using the computer at that time? I know there was an issue where the computer would go into a power save mode and that'd stop the print.
Like 2ct asked; can you give a bit more detail into what the machine is doing when it stops the print. Does it say something like "cancelling print" or heat error, or whatever is on the screen? Does it finish drying? Does it shut off?
You do know that 200 inches is the max size for adobe products. For longer files you have to use the rip to scale it past the 200 inch size.