z axis and ohmic sensor

[jheartley205]

dynatorch xls 5x10 table. Hypertherm powemax 125.
recently the ohmic sensor has been giving us problems along with z axis not going down on the initial start. when I zero x and y and hit start it gives a "torch move to arc start height will exceed the range limit of motion of the torch" fault. you have to manually jog z down to the material then it would run the first cut. moving to the second cut it would stay at jog height and have a miss pierce (torch would light but not cut due to distance) then jog up a little and try to relight. manually jog it down to the plate then it would cut the second cut and so on. I've cleaned the slide for the torch and that doesn't seem to help. auto set point wont work because of the ohmic sensor not working properly. is it possible the ohmic sensor board is toast causing everything else not to work?

[adbuch]

Can you temporarily turn off thc and ohmic sensing and set your cut height manually? That might give us some clues as to where to start looking.
David

[acourtjester]

Some table software have a indicator showing when the ohmic sensor is touching the metal surface, or you could just use a jumper wire to touch them together for testing. I'm sure you understand the ohmic sensor is to reccorect the torch height for each cut. the table follows the G-code but it the correction is not made, it will be off as you are explaining.
You did not say if you have a floating head switch, that would act as a safety or second option for torch height control if the software is setup to do that.
This goes along with David's turning off the THC suggestion.