I just modded my FY3224S with a proper 3-wire grounded power cord... and managed to blow up the power supply board, (in spectacular fashion I might add), in the process of making this thing "safer".
I won't go too deep into my faux-pas, but suffice it to say that you are supposed to connect the SECONDARY-side-gound (low voltage DC ground) to mains-earth-ground. Do NOT, under any circumstances, connect the PRIMARY-side "ground" (from the bridge rectifier) to mains-earth-ground. That isn't a meant to be earth-ground. It's the ground "reference" of the primary.
I've noticed that FeelTech is using whatever power supply they can get their hands on, as mine looked nothing like the ones posted by med6753 & tombddiver. My unit came with a very nice SICO-650 power supply. (Well, it WAS nice 'till I fried it). I put in a "Universal DVD Replacement Power Supply" I managed to find on Amazon. It took some searching to find one with the required +5v & +/-12v outputs.
My mod included a toggle switch in the grounding path, in case I ever have the need to "float" the BNC outputs, the way the unit is shipped from FeelTech. Otherwise that switch stays in the safe/gounded position.
One more note; The sticker on the bottom of the unit is printed on an ink-jet printer. If it gets wet, it will bleed and smear.