Shorted Torch Error

[islander261]

Hello

I am having a problem with an intermittent shorted torch error (85psi LED and Error LED flashing)on a A-60 with the machine torch. This typically happens about every 30 to 60 pierces. Usually the hole in the material is pierced (smaller than usual pierce) but the arc goes out with the error being indicated before the torch starts moving. Rarely this error occurs in the middle of the cut. It happens so fast I can't tell what happens first, the arc going out or the error indication. I have changed consumables and start cartridges many times. I have checked the torch and cable with an ohm meter many times and have never found a short. I have visually inspected the torch (taken apart)several times an never seen anything to cause concern. The air supply has been checked many times for clogs or restricted flow but everything looks good. Inlet pressure to unit is always 100psi (air flowing)- 120psi (no air flowing) measured at air inlet to unit. Very clean and dry air, after cooler, automated tank drain, filter, refrigerated air drier, desiccant air drier and filter. Have tried varying torch pressure within working range (surprisingly wide) with no change. All I have to do to make it work until the next error is to cycle the power to the unit and back up the g code to the last pierce. Typical ohm meter checks with torch connected:

Shield to Work > 20Meg Ohms
Nozzle to work 9k Ohms
Electrode to work 190k Ohms
Electrode to Nozzle 199k Ohms

All measurements are > 20Meg Ohms with the torch disconnected from to unit.

I live in a remote area so I can't just drop by a local welding shop to have the unit checked out. The intermittent nature of this makes me leary of shipping it away only to get it back with a big bill and problem not fixed. Any suggestions of what else to check out?

John