Re: Ground for Gen6 by M_Alban
If there is any difference between the 0V dc 'earth' and 'real earth', it will be negligible, and remember, at most you will have 12-24Vdc (12 on the GEN6, 15-24V on the heated bed) on the frame, which is considered low voltage, and you wouldn't feel it.
Also, the PSU can only supply 60 watts of power, so there's no real chance of major injury, unless the current travels across the heart. ie, touching the frame with one hand, and something earthed with the other. Also, most of the time, a person is not sufficiently earthed to provide a 'path to earth', due to the large resistance across the skin (somewhere in the region of 2 Megaohms) and the resistance between the persons feet and the earth (when standing; if sitting etc the resistance is potentially lessened, although still not enough to allow 12 volts through.)
However, because the frame is 'earthed', in the event of an insulation fault to the frame, a short would occur, and the voltage on the PSU would drop to 0V, either at maximum current, or if the PSU is clever, no current.http://zone.ni.com/devzone/cda/tut/p/id/2827