First thing, what was the voltage supplied by the wrong unit? Almost everything revolves round the answer to that question. I don't have the specs for the 321 (we never used them in my company) but I would assume it required both 12v and 5v from the PSU. This adds another question. What is the pinout of the unit you incorrectly used? You have 4 pins to carry voltage to the unit and there is NO standard pinout for that 4 pin plug. If you got 12v where there should have been only 5v you have a dead unit and I assume no backup of your data.
If you need to try and copy the data from your disks we need to know how they were formatted, Raid 0, Raid 1, Standard or JBOD, each is different in how you recover data from them. You would also need some hardware to convert them to USB (the safe way of attaching them to a computer to minimise data loss especially if you are using a windows computer). RAID 1 is the easiest to recover data from, you have two copies of the data, one on each disk, and you can use a live Linux DVD to do the recovery. The other require recovery software and then don't guarantee full recovery.
Sorry to be so pessimistic but I have seen it all too many times before I retired.