Neutral or ground?

[mrcaptainbob]

I have a new plasma torch that runs on 240v/40a. It has a three prong plug. The unit has an additional exterior threaded terminal that, according to the book, shows it to be an 'earth' connection. I purchased a Leviton three plug model 5378 250v/50a outlet. The Leviton is one end of an extension from the barn electric. It's schematic shows the the two hots and the the third shows 'ground'. I'd like to ground the plasma unit. Can I connect Leviton to the two hots and neutral instead of ground? And connect plasma torch ground (earth) to barn panel ground? The barn breaker panel does have the neutral and ground separate. In effect, the plasma torch would be plugged to two hots and neutral, while it's case is connected to ground. Would that be okay to do? Or must it be connected to two hots and the ground?

[HayZee518]

you'd be better off installing a four wire pigtail and connecting it to a four wire receptacle. the plug has isolated neutral and earth ground terminals same as in the panelbox either the main or sub-panel.
sub-panel has the neutral not bonded to the chassis, has a separate earth ground but at the main panel the neutral is bonded to the chassis.

the plasma torch ground comes off its transformer. has nothing to do with the input power supply.