Flavio,
Most likely the neutral wire and ground are
bonded at the power panel which put them at a
common ground. In other words, what you
propose will work but it presents a potential
safety hazard. The difference is that you
expect current flow on the neutral while you
don't on the ground. If you use the ground
wire there is a chance that nearby electrical
devices with three prong outlets may
experience a voltage at the ground prong.
Then when someone touches that device, they
could potentially feel a shock if the path to
earth ground has less resistance through them
versus the resistance between the XPDI3
switch and the power panel. I think the
chances are really low that this safety
hazard could actually happen, but who wants
to take the chance?
Something for you to think about...what's the
resistance across the XPDI3 case and XPDI3
neutral connection? If you know and
understand the result then you'll be able to
answer your own question.
