Still sorting out my 4X4 GS. Sometimes works fine but often have Height Control/Ohmic issues. Cutting 1/2 inch mild steel with Hypertherm 65. Cut 3/4 of the 18 holes OK then the torch stopped 2 inches above the plate and torch started, shows Ohmic Sensor detected, did it for 2 holes then cut 1 correctly then cut air again. Then went to the profile and cut for a while then crashed and dislodged torch. Could not get torch to move, system was locked up after that.
Reason the torch fired in the air is because the ohmic is getting detected. Usually this is from slag getting inbetween the sheild cap and the nozzle. If you just press STOP. Turn off the plasma. Unscrew the sheild and clear the slag and wipe the nozzle. Then screw the sheild back on. Power up the plasma. Press RUN it will resume. I would contact tech support to go over your system and your software version just to make sure you are up to date.
You can minimize the chance of getting slag blown back inside the shield by being sure that you set the pierce height and pierce delay correctly. You will find the proper settings in the Powermax operators manual mechanized cut charts. Correct pierce height is always higher than cut height....and the pierce delay time must be long enough so that the pierce is completely through the material before x, y or z motion occurs. This will provide the best consumable parts life and will minimize the chance of shorting shield to nozzle. Jim Colt Hypertherm
