You can do three phase on only three wires - most long distance power lines are done that way - but that would be unearthed, and therefore not recommended. If it is a 190/208V version rather than a 220/240V version it is probably expecting two of the three phases plus ground. Dunno. Passwords are only 4 letters IIRC so shouldn't be that difficult to crack if you've got a terminal emulator card in a PC. I'm afraid a quick glance through the pocket reference hasn't revealed anything useful :-( Philip.