[finyuk2005]

Hi there
Almost have my plasma table working, unfortunately the manual for my Jasic cutter has the wiring for Arc start and Arc ok back to front, and because of that it sent 12v to my torch height controller :Sad ! So it blew up!
I have now sorted that wiring out and am waiting for a new THC board,

But the maker of the THC mentioned that i was asking for trouble having my grounds isolated as I asked him if having the +5v and 0v connected directly to the 5v power supply, instead of having the 0v connected to ground, may have caused issues.

The reason i have not connected any of the 0v of the power supplies was because i was getting interference and encoder issues when everything was connected to ground.
I have a separate 24v dc supply for the logic side of things (motion controller and the servo drives) and another for the limit switches and relays and z axis brake etc. And then a 5v supply for the THC and an arduino,
Am i right or wrong to have the 0v/negative of each of these DC supplies isolated from ground?

I do have all 240v supplies for the servo drives and the power for the DC supplies as well as one end of each cable shield, and all parts of the table itself all connected to earth/ground

Any wisdom, do's or don'ts much appreciated!

sorry for the long essay :HaHa

[Al_The_Man]

There was one major table manuf that used a GND rod at the machine, they grounded all earth GND's to this point, including the PC based controller, table and pilot arc etc, .
I never saw any problems of a GND nature over the years I was associated with it.