I did some testing of the ground integrity check w/o opening mine up. I connected the ground pin of the EVSE to an earth ground (a screwdriver driven into the dirt) instead of the house ground. It still passes the ground check and works normally, even though the impedance between neutral and gnd is very high, so this rules out the idea that it's checking the for neutral shorted to ground. My ammeter shows that there's a constant ~0.6A (sounds high to me.. but my two ammeters had the same reading) current running from hot to gnd. It checks the ground continously... if you disconnect it, the green ready light blinks, and when you reconnect the ground, it goes solid again.
So.. since it doesn't try to short neutral to gnd, and *if* there's nothing in the hot path through the relays that can't handle 240V, I think it should work on 240V with a power supply that steps it down to the 20V that the control board needs.
Some questions from the photo's I've seen of the insides:
1) Why is the small relay for GFI trip test 13A? Isn't that overkill?
2) Why is the fuse 25A when the main relays can handle only 20A, it's supposed to be used on a 15a circuit, and have 12A max current draw?
3) If it has a 25A fuse, why didn't the fuse blow when Ingeneer did the 26.5A smoke test?