If you want to shut enclosures off, that means you are willing to stop IO from the application servers.
The right way to shut enclsures off with out coruppting data will be,
Shut the servers down, or in case of UNIX, unmount the file systems. Then shut the DS4000 controllers off. Finally,shut the enclosures off.
You have to allow 2 minutes time between each step.
When you want to bring the system up, use the revers order, starting from the enclosures.